Title : Facility to Support RADARSAT Type : Antarctic EAM NSF Org: OD / OPP Date : January 5, 1994 File : opp94011 National Science Foundation Office of Polar Programs Washington, D.C. ENVIRONMENTAL DOCUMENT AND FINDING OF NO SIGNIFICANT AND NOT MORE THAN MINOR OR TRANSITORY EFFECT Facility to Support RADARSAT, A Joint Project of the National Aeronautics and Space Administration (NASA) and the National Science Foundation (NSF) at McMurdo Station, Antarctica DECEMBER 28, 1993 I. FINDINGS The National Science Foundation (NSF), the lead agency, in cooperation with the National Aeronautics and Space Administration (NASA), has prepared an Initial Environmental Evaluation (IEE) and an Environmental Assessment (EA) as a combined environmental document, for the construction of a 17-m diameter radome and 130-m2 support building 1.8 km from the center of McMurdo Station, Antarctica. The facility, support buildings for the RADARSAT project which is to receive satellite data for ongoing and future scientific investigations, is to be in operation for 15 to 20 years. Three to four people would be required throughout the life of the project to provide year-round, seven day per week, 24-hour per day staffing for remote operation of the facility from the Crary Science and Engineering Center (CSEC) in McMurdo. At the conclusion of the project, the facility would be dismantled and removed from Antarctica, unless the responsible decision-maker makes a decision with appropriate environmental evaluation and decision documentation to continue use of the facility, considering the condition of the facility and the continued need for the facility. It is possible to use the facility for radio frequency (RF) transmission purposes at a future date. The decision to initiate RF transmission operations at the site would be evaluated as a separate decision after an assessment of radiation safety hazards, electromagnetic interference (EMI) compatibility, and additional environmental considerations were performed. Based on the analyses in the environmental document (IEE/EA), the NSF Office of Polar Programs (OPP) has determined that implementation of Alternative D is not a major federal action which would have a significant effect on the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969 nor is the action one which would have a more than minor or transitory effect on the antarctic environment, within the meaning of the NSF implementing requirements for the Protocol on Environmental Protection in Antarctica. The selected alternative, D with identified mitigation, provides for the construction, operation, and removal of two buildings for support of the RADARSAT project. To lessen the possibility of power outage at the facility, a comprehensive analysis and power conservation program for McMurdo Station's power plant and electric energy network will be initiated upon completion of the buildings. Operation of the receiving dish would be curtailed until an energy conservation and improvement program was implemented. Use of the facility or site for programs or projects other than or in addition to the RADARSAT project would require appropriate environmental evaluation and decision by the NSF. The construction, operation, and removal of the facility is consistent with the NSF's efforts to promote scientific investigations, cooperate with other federal agencies, and protect the antarctic environment. s/Dr. Cornelius W. Sullivan 1/05/94 Dr. Cornelius W. Sullivan Date Director, Office of Polar Programs National Science Foundation 4201 Wilson Blvd. Arlington, Virginia 22230 II. PURPOSE AND NEED FOR THE PROPOSED ACTION The National Science Foundation (NSF) in cooperation with the National Aeronautics and Space Administration (NASA) proposes to construct, operate, and decommission a ground receiving station for the capture of real-time data as an earth orbiting satellite (synthetic aperture radar satellite) passes over McMurdo Station, Antarctica. The ground station antenna, located north of McMurdo Station (77 51' S, 166 40' E) near Arrival Heights (see Attachments A, B, and C), would consist of a ten-m dish enclosed in a 17-m radome and a 130-m2 building for electronic receiving equipment and occasional use by a technician. Construction of the facility requires an approximately 245-m long 3-m wide access way and installation of: a 1.8 km fiber optic line from the CSEC at McMurdo Station; an approximately 396-m power line from the station grid to the site; an underground conduit between the radome and the support building for cables and a boresight antenna with electronics equipment for communication with the CSEC by telephone modem located near Building 126 on the lower side of Observation Hill. The facility, 1.8 km from McMurdo Station, is not near any areas of historical interest. However, the site is near a Site of Special Scientific Interest (SSSI) No. 2 "Arrival Heights, Hut Point Peninsula, Ross Island". The proposed facility would receive real-time satellite data in the Ross Sea sector of Antarctica, where coverage provided by the German ground station at O'Higgins Station in the antarctic peninsula and the Japanese ground facility at Syowa Station, Antarctica do not extend. The need for a ground station at McMurdo is validated in a report by the U.S. science community (Reference A). Data received would be used for scientific research of the antarctic land mass and oceans. The prefabricated buildings would be unmanned, except for occasional maintenance work at the facility, requiring no water or wastewater utilities. There would, however, be three to four people throughout the life of the project providing year-round, seven-day per week, 24-hour per day staffing for remote operation of the facility from the CSEC in McMurdo. Emergency food and water supplies would be provided at the facility. A maximum of 120 kVA are required to operate the facility. Power would be provided by generators located in nearby McMurdo Station. Issues related to the proposed action are: Removal of the facility when the RADARSAT project is concluded; Aesthetic effects of the facility; Health and safety of personnel during construction and operation; Interference with ongoing or future science projects; and Power and fuel requirements to build and operate. III. ALTERNATIVES Alternative A. Do not build the facility This alternative is the "No action" alternative which is required in the consideration of environmental effects. In this alternative the NSF would take no action to develop the facility and would not participate in the acquisition of real-time satellite data. Alternative B. Build the facility at the preferred site, a knoll overlooking McMurdo Station In this alternative the proposed facility would be constructed on a knoll overlooking McMurdo Station. The facility would be in operation for 15 to 20 years, after which it would be decommissioned, dismantled, and removed from Antarctica. Any materials that could be successfully used in other projects would be recycled. Other materials would be sorted and retrograded from Antarctica for appropriate recycling or disposal. Should continued operations be desired at the conclusion of the RADARSAT project, use of the facility would be considered within the appropriate environmental review and decision by the NSF. In the development of this alternative, four non-fossil fuel energy sources for facility operation were considered. However, as described below, non-fossil fuel energy sources do not appear practical for operation of the facility in the extreme antarctic environment. Photovoltaic Cells (PV) PV cells are a well-developed, extremely reliable method of harnessing solar energy, making them ideal for small, remote, unattended installations. The efficiency of commercial PV cells is about 10% to 15%. Their life expectancy is about 20 years. Initial cost of a PV installation is about $4000 per kVA, which is not competitive with other sources in normal applications. Wind Power A perfect wind turbine would convert about 60% of the potential energy in wind into useful energy. Depending upon the aerodynamic, electrical, and mechanical efficiencies of the turbine, more realistic values range from 20% to 40%. Wind power is an attractive alternative to diesel generators, and small units have proven to be reliable in remote facilities. However, large wind turbines capable of supplying energy required for the RADARSAT facility have not been developed and tested in Antarctica's harsh environment. Fuel Cells The efficiency of fuel cells using petroleum fuels, is higher than that of an internal combustion engine (nearly 60% compared to about 35% for a diesel generator). The emission rates of nitrous oxide and sulfur dioxide for fuel cells is very low and they create no noise. Fuel cells are still in the developmental and prototype stage and are not suitable for reliable operation at a remote facility. Hybrid Power System A combination of alternate energy sources could be used to create a hybrid system, much like that used at Black Island, a facility run by the NSF not far from McMurdo Station. However, Black Island's total power requirement of 5 kVA is considerably less than the 120 kVA needed to operate the RADARSAT facility. It is not known if such a system would meet specifications needed to supply uninterrupted power for the facility. Further study and demonstration is required. All of the alternatives to diesel generators have qualities which make them environmentally desirable, such as the reduction of air emissions associated with burning fossil fuels and the reduction in noise. Unfortunately, there is insufficient information on system reliability to adequately assess safety and utility of such systems for powering the facility. Alternative C. Build the facility at a location other than that proposed In this alternative the facility would be constructed at a site other than that described in Alternative B. The Jet Propulsion Laboratory (JPL) was consulted as the NASA representative for possible site selection. A primary concern was finding a site that minimized horizon obstruction of a smooth, flat view. An unobstructed view of Pine Island Bay (75 degrees south, 100 degrees west with a local azimuth bearing from McMurdo Station of 90 to 120 degrees) would provide "line of sight" view of a satellite 5 to 10 degrees above the horizon. The horizon visibility from the rooftop of Building 165, located in McMurdo Station, represented a worst case horizon view due to the immediate surrounding hills. The JPL indicated that this site was sub-optimal, and it would be a last choice if other sites were not available. To minimize the horizon blockage by the hills to the north and east of McMurdo, a site above the town center ground clutter is needed. Site evaluation examined prospective hilltop locations on the perimeter of McMurdo Station. The availability of sites was constrained by existing land use and by pertinent safety, environment, and cost considerations. The site selection factors included: proximity to roads and McMurdo Station for year-round personnel access; minimal site preparation; horizon visibility; and land use conflicts such as the existing explosives storage yard, Arrival Heights Site of Special Scientific Interest (SSSI), radio quiet zone, and high frequency (HF) radio receiving antennae. Because horizon elevation clearance data were not available, a physical site investigation was completed. Four sites were examined (see Figure 1): * The summit of First Crater (now the site of the New Zealand Telecom satellite communications earth station); * The summit of the knoll overlooking McMurdo Station and located near the intersection of the Arrival Heights access road and the main service road leading from McMurdo up the overlooking terrain; * The site of the existing HF receiving antenna (Rosette phased array loop antenna) adjacent to the existing explosives storage site; and * The summit of Crater Hill. The JPL indicated that all of these sites provided visibility to Pine Island Bay. The proposed sites were then further evaluated. The principal factors which eliminated three sites were: First Crater. This site conflicts with the management plan for SSSI No. 2; HF Receiving Antenna/Existing Explosives Storage Site. This site conflicts with the current land use and would not be safe for the facility; and Crater Hill. This site is too remote and would require costly construction. Also, due to travel distance from McMurdo Station and severe weather, the site was considered unsafe for routine use. The summit of the knoll overlooking McMurdo appeared most favorable. It has good horizon clearance, good proximity to developed roads, close proximity to McMurdo Station, reasonable site preparation requirements, and no conflicts with current or anticipated land uses. Alternative D. Build the facility as described in Alternative B and develop energy conservation program for McMurdo Station Power Plant In this alternative, the facility would be constructed as in Alternative B. However, an energy conservation program for the electric power generating plant at McMurdo Station would be implemented. Electric power to operate the facility would be drawn from existing on-line and reserve capacity. Any encroachment upon the generating safety margin of the existing power plant would be compensated with the development and enforcement of an energy conservation program. IV. ENVIRONMENTAL EFFECTS AND MITIGATING MEASURES Note that environmental effects refer to Alternatives B, C, and D unless otherwise noted. A. Removal of the facility when the RADARSAT project is concluded Minor environmental effects are anticipated from decommissioning the facility in 15 to 20 years. Heavy equipment would be required to dismantle the radome and support building causing some minor noise, exhaust, and dust from leveling and reshaping the site. The underground conduit would also be removed as part of the facility decommissioning. The site would be returned to as close to a natural condition as possible. Leveled areas would be reshaped to approximate the 10 percent slope of the backside of the knoll. The materials in the receiving dish and the dome will require dismantling through approximately six months of specially skilled labor. Electrical equipment and hardware that could be reused at McMurdo Station would be replaced into inventory or used in ongoing projects. B. Aesthetic effects of the facility The proposed construction site is currently used as a fill material collection site. Heavy equipment routinely operates at the site, collecting the top few inches of soil above the permafrost. Therefore, ground disturbance would not be new, nor would operation of heavy equipment in the area. The addition of the antenna radome would impact the overall aesthetics of McMurdo Station because it would be visible from "downtown McMurdo" as well as from long distances. The size, shape, and appearance of the antenna radome is dictated by its function. Little can be done to alter these, other than changing the color of the radome to blend into the local scenery. The industry standard color is white which increases solar deflection to keep minimum interior temperatures and avoid damage to equipment. Cooling the equipment is not a major concern at McMurdo Station. However, the white radome would blend well with the predominate colors in summer, white and black. The support building, which could not be seen from McMurdo Station, would be dominated by the larger radome making it less obvious. The top of the building would be below the antenna to avoid obstruction of the horizon. This lower positioning of the support building would make it less visible from observation points below the site. A neutral color for the exterior would be selected to blend with the slopes which are dark in the summer months when most visitors are at McMurdo Station. Fiber optic transmission lines placed on top of the ground in protective conduit and power cables would be visible. Trenching is required to place lines below ground. However, trenching is very difficult to perform in the shallow soils and dense rock that surrounds McMurdo Station. The placement of lines on the land surface at McMurdo Station has proven to be effective. Portions of cable will be placed underground at vehicle crossings to protect the cable. The new cables would parallel existing cables between McMurdo and Arrival Heights. The new section of cable run between the existing cable splice box and the facility would be blocked from view from downtown by the top of the hillside. In-town, cables will be placed on stanchions or telephone poles. C. Health and safety of personnel during construction and operation Rigging for crane operations would follow the guidelines and requirements provided in the "Safety and Health Manual under the Hoisting and Rigging Program". Blasting operations would follow established procedures utilizing containment mats to prevent debris from being dispersed into the work area. The use of ear and eye protection is required during these operations under the guidelines provided in the "Hearing Conservation and Personal Protective Equipment Programs" contained in the Antarctic Support Associates (ASA) Safety and Health Manual. The ASA Explosive Safety Program is currently under development. Additional guidelines from NSF are available. Heavy equipment operators would pay special attention to visibility problems, such as icing and fogging of windows, by scraping ice from cab windows until adequately defrosted. Redesign of the interior of the dome surface has eliminated the depression in the center of the dome floor making it a safer work environment. The safety of personnel that may contact power cables is a concern. However, cables to be laid on the ground presents no new or unusual hazards. Cables have been laid on the ground in previous projects. The same proven precautions will be followed. Concerns regarding welding and proper eye protection are addressed in the Personal Protective Equipment Program contained in the ASA Safety and Health Manual. The following potentially hazardous jobs: Rigging for crane operations; Blasting; Heavy equipment operations; High voltage operations; and Welding have well trained and experienced personnel available for job completion. All of the potentially hazardous jobs listed are routine and accepted trades now in practice at McMurdo every season. Welding and metal fabrication would use oxygen and acetylene tanks, high pressure hoses, and flammable liquids (mogas). Heavy equipment operations would use rigging cables, hydraulic lines, and their vehicles contain diesel fuel and oil. Potentially high winds and rugged terrain present the dominant physical hazards. Extreme caution will be used during operations being conducted during windy conditions or on rugged terrain. Vehicles, including those used for collecting fill material, occasionally traverse through the area between the proposed facility and the existing splice box where new cables will be set on the ground. To protect the cables and prevent the cables (including the 4160 V line) from posing a safety concern to personnel working in the area, a portion of the cable would be set underground in a conduit to create a road crossing. Flags and signs would be used to advertise the presence of the cable and direct personnel to road crossings. D. Interference with ongoing or future scientific projects In Alternative A, the NSF and the scientific community would not be able to acquire highly valuable scientific data from a unique space-based remote sensing satellite as it passes over the Ross Sea area. The facility site in Alternatives B and D, is located very close to SSSI No. 2 (Arrival Heights, Hut Point, Ross Island; see Attachment D). The main receiver in the facility is a receive-only device which would not create any high frequency interference that could disrupt sensitive electromagnetic investigations or communications. Thus, there should be no direct interference problems for nearby instrumentation. The boresight antenna would transmit at three discrete frequencies in the range of 2250 Mhz, and it would also transmit at three discrete frequencies in the range of 8025 to 8400 Mhz with a three decibel (dB) bandwidth of two degrees at 8213 Mhz. There are no current or proposed science projects based at SSSI No. 2 that operate in the electromagnetic spectrum used by the boresight system. Therefore, no adverse effects are expected in the short-term. Present research interests do not indicate any sensitivities in the identified spectrum. The emitter is located outside the SSSI boundaries and isolated by the natural terrain. In addition, the boresight would not continuously emit energy. It would be used only for a short time prior to each tracking operation, projected to be four to six times per day. These events are easily recorded and could be readily evaluated for impacts on existing or proposed science projects. E. Power and fuel requirements to build and operate The power requirement for the operation of the radome, the largest power user of the facility, is estimated to be approximately 56 kVA per day. This estimate is based on the assumption that the satellite would pass over six times per day for 15 minutes (900 seconds) per pass. Maximum power draw would be 120 kVA for 5 seconds per pass. Steady power draw would be 75 kVA during a pass while quiescent power draw for the entire system when not tracking would be 55 kVA. The average power draw per pass would be: (5/900)*120 + (895/900)*75 = 75.25 kVA. With six passes per day at 900 sec per pass, 5400 tracking seconds per day and steady power draw, the system would require: (5400/86,400 seconds per day)*75.25 + ((86,400-5400)/86,400 )*55 = 56 kVA per day. Fuel use for the construction of the facility would be minor. Fuel to operate an oil fired furnace at the site would be stored in a day tank similar to those located in McMurdo Station. The furnace in the support building is needed to maintain proper temperatures for equipment housed in the facility. Standard operating procedures would be employed to refill and maintain the tank to prevent spills from occurring. F. Short-term effects Environmental impacts would be expected from the preparation of a site to erect the enclosures. Some grading and trenching would be required which could produce dust. Explosives may be used to loosen the soil below the permafrost as necessary to grade a level site. Dust emissions would be kept to a minimum by wetting the area with brine water when weather conditions warrant its use. Because the structures are prefabricated, little waste would be generated during construction. The number of personnel at the site and transportation to and from the site would be highest during construction. After construction is completed, personnel would only be at the site to perform maintenance and repairs to equipment. No change in water quality or flow would occur at the site. There is no defined pattern at the site that would be altered by the construction of the proposed facilities. A culvert would be placed under the proposed road at a point where drainage does occur. Hazardous materials would not be used or stored at the site. Human waste from personnel temporarily working at the site would be collected and disposed of through McMurdo's human waste disposal facility. G. Long-term and cumulative effects The long-term and cumulative effects of operating the facility may be important to the total electrical power requirements of McMurdo Station. If power for the receiving dish were drawn when reserve generating capacity was not available due to equipment failure, maintenance requirements, or severe weather; power could be unavailable to operate the facility. To lessen the possibility of power outage at the facility, a comprehensive analysis and power conservation program for McMurdo Station's power plant and electric energy network would be initiated by the NSF upon completion of the buildings in Alternative D. Operation of the receiving dish would be curtailed until an energy conservation and improvement program was implemented. Implementation of the program would ensure that electrical power would be available to the facility without curtailment of operation or reduction of necessary services at McMurdo Station. Transportation of personnel to maintain and repair equipment would add to exhaust and fugitive dust emissions. The impacts from these infrequent tasks are considered minor. The project will require a minimum of three to four people; seven days per week; 24 hours per day in CSEC year-round. This will require one dedicated room in CSEC (room 205), 21.5 m2 for both the austral summer and winter. H. Unavoidable effects and irretrievable and irreversible commitment of resources Use of fuel in the construction and operation of the facility is an irretrievable use of natural resources. However, this use of available petroleum resources is considered to be minor. No action undertaken in the construction of the facility or its use represents an irreversible condition to the antarctic environment. I. Consistency with the plans and programs of the NSF and others Construction of the facility would support the implementation of the RADARSAT project. The radome and support building would change the traditional use of the proposed site. The site has been disturbed for the gathering of road fill and structures have never been placed there. Although there would be a change in the traditional use of the proposed site, the physical and environmental characteristics of the neighboring environment are suitable for the proposed activity. K. Mitigation of other environmental effects The impacts associated with construction of the facility would be mitigated as follows: Construction of the antenna and radome foundations The antenna and radome foundations require site preparation. An area approximately 335 m2 capable of accommodating the 17-m radome would be cleared of rock debris larger than 15 cm. The area would then be graded level and fill material would be removed and stored for backfill. Explosives may be required to open a trench approximately 3.05 m in the bedrock for placement of a 1.5-m diameter tube connecting the radome to the support building. The tube would house communications and electrical wiring. Standard safety procedures and precautions will be used to place and set explosive charges. The possible use of explosives is not unusual or a unique risk to personnel or the environment. An area of approximately 1500 m2 would be impacted by the movement and set up of a 70-ton Grove crane used to erect the radome. Activities would be confined to the areas described above. Backfill would be compacted using brine water from the water plant to maintain a satisfactory compaction density. The water would also be used to control dust emissions from the site, if necessary. Precast, reinforced concrete slabs manufactured in the United States would be used for the foundations, thus eliminating the need for manufacture on-site and, in turn, reducing construction debris. Precast slabs may be reused upon decommissioning the facility. Construction of the support building An area approximately 2790 m2 would be impacted by construction of a 130-m2 support building erected approximately 30.5 m from the radome. The proposed site for the building would require regrading to lower it a maximum of 1.22 m. An area approximately 1045 m2 would be regraded. Construction activities would be confined to the designated area to mitigate environmental impacts. Brine water would be used to control dust emissions when weather conditions warrant its use. The building would be prefabricated in the United States, thereby reducing waste generated during on-site construction. Surface water drainage would be directed away from the building to prevent frost heaving damage. Construction of site access way An access way of approximately 245 m would be required to link the proposed facility to the main road. Construction would require little more than grading to provide a smooth surface for vehicles to pass over. Construction of a roadbed is not needed at the site. Culverts would be installed where necessary to allow natural drainage to occur. Installation of a Fiber Optic line A fiber optic line would be installed from the facility to the CSEC, approximately 1.8 km. The line would have 24 single-mode fibers in Uniduct (single cable). It would be placed on the ground near Building 143, then on existing poles and stanchions to the CSEC. No adverse environmental impact is expected. Installation of a power line No special requirements are needed for installation of the power line. Consideration for wildlife near the site The site is not habitat for any significant assemblages of wildlife. The site has been visited by South Polar Skuas. In the unlikely event of the discovery of nesting skuas, precautions would be taken by workers to avoid disturbance of the nest and birds. V. CONSULTATION WITH OTHERS Ms. Carol Andrews Environmental Engineer, ASA Mr. Frank Brier Facilities Manager, NSF/OPP Mr. Erick Chiang Manager Polar Operations, NSF/OPP Mr. Robert Cunningham NEPA Compliance Manager, NSF/OPP Dr. Jane Dionne Acting Environmental Officer, NSF/OPP Dr. Harry Mahar Health and Safety Officer, NSF/OPP Mr. Peter Karasik Associate Compliance Manager, NSF/OPP Dr. Steve Kottmeier Manager, Laboratory Services, ASA Mr. Terry Johnson Environmentalist, ASA Mr. Quentin Rodin Lead Blaster, ASA Mr. Patrick Smith Electronics Engineer, NSF/OPP Mr. Michael Young Director, Information Systems, ASA ATTACHMENTS Figure 1: Sites Considered for RADARSAT Facility Attachment A: Facility Site Location Attachment B: Facility Site Plan Attachment C: Facility Site Profile Attachment D: Sites of Special Scientific Interest No. 2, Arrival Heights, Hut Peninsula, Ross Island References and Background Information (References are available at NSF/OPP offices Arlington, VA) A. McMurdo SAR Facility. Ad Hoc Science Writing Team, BPRC Technical Report #91-01, Byrd Polar Research Center, Ohio State University. B. Carter, William. 1991. The Scientific Benefits of a Geodetic VLBI Station at McMurdo. National Geodetic Survey, Rockville, MD. C. NSF and NASA. 1993. Memorandum of Agreement between the National Science Foundation and the National Aeronautics and Space Administration for Spacecraft Tracking and Data Acquisition at McMurdo Station, Antarctica, September. D. Naval Electronic Systems Engineering Center. 1993. Electromagnetic Environmental Effects (E3) Survey, Arrival Heights Site of Special Scientific Interest (SSSI) No. 2 for McMurdo Station, Antarctica. Charleston, South Carolina. January. E. Hewlett-Packard Company. 1992. EMI Site Survey at Amundsen-Scott Station, McMurdo Station, and Black Island. Fullerton, CA. F. Smith, P.D. 1993. Staff Paper. Description and Requirements of the RADARSAT Project. BC:JD:PK:pk/RADAR1.doc DESCRIPTION AND REQUIREMENTS OF THE RADARSAT PROJECT Prepared by Patrick D. Smith NSF, Office of Polar Programs December, 1993 I. Description of RADARSAT Project The National Science Foundation, Office of Polar Programs (NSF/OPP) and the National Aeronautics and Space Administration (NASA) Ground Networks Division, have a Memorandum of Agreement (MOA) for the installation and operation of a large aperture satellite tracking ground station at McMurdo Station, Antarctica (77 degree 51 minutes S, 166 degrees 40 minutes E). McMurdo Station is the largest of the three year-around antarctic research stations maintained by the United States. NASA, through its funded science support activities conducted at the Jet Propulsion Laboratory (JPL), contacted NSF/OPP in early 1990 regarding the support of a large satellite tracking station at McMurdo Station. NASA has entered into a long-term agreement with the Canadian Space Agency (CSA) for access to data produced by the forthcoming CSA remote sensing satellite, RADARSAT. RADARSAT is a low earth orbiting satellite in a sun synchronous polar orbit that carries a synthetic aperture radar (SAR) imaging system as its primary payload. The RADARSAT SAR imager represents a follow-on to the successful European Space Agency ERS-1 satellite, launched in August, 1991, which also carries a SAR imager. A primary objective of JPL was to establish a data receiving station at McMurdo Station to complement the two existing antarctic receiving stations, one run by Germany at the Chilean O'Higgins Station and one run by Japan at the Japanese Syowa Station, originally constructed for the ERS-1 mission and future missions, such as RADARSAT. SAR imagery is produced by the active illumination of the ground by the satellite imager with microwave signal, with the satellite recording the signal backscattered by the ground. In the case of RADARSAT, the imager will be able to produce images with a resolution of 30 meters. The use of microwave imaging, instead of the familiar visible light or near infrared, is that the microwave illumination and reflection can penetrate cloud cover and the electromagnetic frequency of the microwave energy can reveal surface detail and properties that are not possible with the optical wavelengths. The value of all-weather imaging for Antarctica is highly significant given the high level of cloud cover over the continent at any given time. Additionally, due to the absence of sunlight at the extreme southern latitudes for a large portion of the year, the SAR imager enables imaging to continue on a year-around basis, while optical imaging must cease during a portion of the year. The value of SAR imagery in support of antarctic science has been documented by the report contained in Reference A. The ability to recover a continuous, daily or near-daily, stream of SAR images from Antarctica enable the first ever detailed surveillance of Antarctica and its surrounding sea ice such that fine time scale events can be monitored on a continental basis. It should be noted that NSF/OPP funds a significant amount of glaciological and sea ice research that would have a direct research interest in the imagery of Antarctica produced by RADARSAT. NSF/OPP funded scientists participated in the development and recommendations provided in Ref. A?. The intent of JPL, on behalf of NASA funded sea ice and glaciology science, was to establish a ground station in West Antarctica that would fill a coverage gap that results from the incomplete coverage of Antarctica and the adjacent seas from the two existing ground stations. This is of great significance, since the high data rates produced by SAR imagery satellites either preclude or highly limit the on-board storage of raw image data. Thus, in order to recover the raw data produced by the imager, it is necessary to have a ground receiving station able to maintain "line of sight" tracking as the satellite passes over the scene of interest. The high latitude of McMurdo Station enables it to "see" approximately 10 of the 14 revolutions per day that RADARSAT will make over Antarctica. With each revolution, RADARSAT will image a different ground scene, and the orbit is designed such that a given ground track will repeat after a finite lapse of days, such that the entire continent of Antarctica north of approximately 80 degrees south will be completely covered through one master repeat cycle. McMurdo's unique location will permit it to collect data throughout all of West Antarctica and the surrounding continental ice margin for the development of a thorough and routine time series never before possible. In parallel with the initial dialogue with NASA and JPL regarding the value of a SAR imagery ground receiving station at McMurdo, NSF/OPP was also approached by the National Oceanographic and Atmospheric Administration National Geodetic Service (NOAA/NGS) regarding its scientific interest in implementing a radio astronomy receiving station at McMurdo Station for the purpose of Very Long Baseline Interferometry (VLBI), and the requirements of a VLBI receiving station can be parallel to those of a SAR receiving station. VLBI entails the observations of galactic noise sources that have extremely time/frequency stable radio emissions such that the sources can be used as extremely accurate triangulation references. When two or more VLBI receiving stations simultaneously observe and record the emissions of a galactic source, a combined data analysis can reconstruct the baseline separation between the two ground stations to a precision of a few millimeters, all on the scale of continental separations. VLBI observations have many uses in the field of geodesy, such as the measurement of continental drift and orbital dynamics studies of the earth, and the scientific merit of a receiving station at McMurdo is documented in the NOAA/NGS report contained in Ref. B. Much the same as for the NASA/JPL interest in filling a coverage gap over West Antarctica by placing a receiving station at McMurdo, NOAA/NGS desired a VLBI station at McMurdo to fill a gap in coverage for the production of baselines that tie Antarctica to the other continents. The existing SAR receiving stations at O'Higgins and Syowa also double as VLBI receiving stations. The common attributes are, in general, the size of the antenna (large apertures are needed), the fact that a tracking antenna is needed, and the general complexity and sophistication of the electronic systems required to receive and record the signals. It became readily apparent to NSF/OPP that the natural synergism that occurred at the other antarctic SAR receiving stations should also occur for the proposed McMurdo SAR station, lending even further weight to the value of a McMurdo facility. As the course of the dialog between NSF/OPP and NASA continued regarding the issues and uses of the proposed McMurdo tracking station, it became apparent to NASA that the facility could also be of value for future operational requirements in support of NASA science satellite launches. A large number of earth remote sensing and research satellites scheduled or proposed for launch well into the next decade are intended for polar orbit. An example will be the forthcoming Mission to Planet Earth, Earth Observing Satellite (EOS) series intended for long term global change monitoring. Many of these satellites will be launched south from Vandenberg Air Force Base in California into polar orbit. In order to assist in early orbit insertion maneuvers, NASA must rely on special aircraft outfitted with telemetry tracking systems, to collect spacecraft telemetry and relay it back to launch operations as flight controllers adjust periodic spacecraft thruster firings to place the satellite into proper orbit. These orbital maneuvers are critical to the success or failure of multimillion dollar space missions. The extreme southern oceans in the Pacific, and in particular Antarctica, represent a gap in the data coverage for these critical maneuvers. The special aircraft cannot penetrate as far south as the viewing represented by a McMurdo ground tracking station. Additionally, each launch of this special aircraft has an expense on the order of $350,000. It is quite likely that an aircraft will launch in support of a satellite launch, only to find out that the satellite launch was terminated at the last minute. However, the commitment in funds has occurred regardless, as the aircraft must launch some time prior to satellite liftoff in order to be prepositioned. NASA has determined that it will be of potential operational benefit to use a ground tracking station at McMurdo to augment, or perhaps replace, the special aircraft used for launch operations. This would greatly benefit the overall NASA mission. Consequently, another value for a McMurdo satellite tracking facility was identified. A survey of the various uses proposed by the SAR-class satellite ground receiving station indicate that it jointly supports significant and long term scientific and operational requirements of three different U.S. Federal agencies. The common factors among these requirements are the size and complexity of the ground station, the logistics infrastructure required to operate and maintain such a facility in a remote location, and the unique high southern latitude afforded by the location of McMurdo. As such, the proposed McMurdo satellite receiving station is considered by NSF/OPP and NASA as a significant national resource. As the executive manager of the United States Antarctic Program, NSF/OPP is uniquely distinguished from all other Federal agencies to provide leadership pertaining to the U.S. national interests in Antarctica. It is for this reason that NSF/OPP and NASA have entered into an agreement pertaining to the implementation and operation of a McMurdo satellite ground receiving station. II. Requirements of RADARSAT Project 1.0 Satellite Visibility Dynamics The proposed satellite ground station is intended to track low earth orbit, polar orbiting satellites. This general class of satellites have orbital altitudes of typically 750 km, with a resulting orbital period of typically 100 minutes and a resulting number of total revolutions of the earth of typically 14 revs/day. Because of McMurdo's latitude, approximately 10 to 12 revs/day of this type of satellite can be seen, with sky tracks that can occur at almost any location in the sky. The sky tracks will have varying rise and set azimuths, and the sky track elevation when the satellite is at closest approach can vary from below the horizon to local zenith. A typical satellite overflight, or pass, can last for as few as 5 minutes to as many as 15 minutes. 1.1 Horizon A consequence of the satellite pass dynamics described above is that the tracking antenna system must be able to acquire the signal when the satellite is low on the horizon. This is beneficial for tracking satellites with maximum elevations near zenith, as these satellites have a high relative motion with respect to the ground, which result in radio frequency effects (the Doppler shift) that complicate late acquisition of the signal. Additionally, there is a specific geographic location of particular interest to NASA glaciologists, as specified by JPL, that of Pine Island Bay (approximately 75 degrees south, 100 degrees west). The typical satellite geometry described above will result in a visibility from McMurdo of roughly 7 degrees to 15 degrees in elevation of a satellite that is directly above the Pine Island Bay coordinates. In order for the McMurdo satellite ground station to track and acquire data from this area of special interest, the local horizon of as seen from the ground station must be clear to at least 5 degrees in elevation, or as close as possible to this level. The local azimuth bearing from McMurdo to Pine Island Bay is in the vicinity of 90 degrees to 115 degrees. Thus, the McMurdo ground station location needs to have a clear view towards the East to East-Southeast. Although the view to the East was the most sensitive horizon clearance azimuth specified by JPL, a general requirement by JPL was to find a location with the best possible horizon, including the North. This general requirement is to maximize the ability of the system to acquire satellites low on the horizon and to extend the view towards the marginal sea ice zone to the North, another area of particular scientific interest. 2.0 Facilities The general requirement calls for two primary structures at the tracking site: the antenna under a protective enclosure, and a man-rated (i.e., heated, thermally controlled) building to house all of the specific electronic systems that must be close to the antenna system due to design constraints. Two additional facility requirements are required: a manned control room provided within a building within the confines of McMurdo town center and an unattended antenna calibration target (referred to as the boresight facility) located within a few km of the tracking antenna and no lower in elevation than 3 degrees below the zero degree elevation reference of the tracking antenna. 2.1 Tracking Site 2.1.1 Antenna The antenna is required to be housed under a radome for the protection and survivability of the antenna system. The system design for the facility requires an antenna of a diameter of 10 meters. This antenna must be mounted on a high slew-rate elevation over azimuth tracking antenna system, with this type of antenna system a standard for tracking low earth orbit satellites at the orbit geometries described above and representative of RADARSAT. The antenna is consequently very massive, and it also represents a significant wind load. McMurdo frequently experiences storm winds with peak gusts above 125 knots, and sustained winds above 100 knots. These high winds would cause destruction of an exposed antenna system, unless great additional expense, well beyond the expense of a protective radome, were taken to harden the antenna. Additionally, the mechanical resistance caused by the wind loading of the exposed antenna would, on occasion, cause an added load on the tracking antenna motors. To compensate for this load, thus enabling tracking in winds below the level where the antenna has to be stowed in a protective mode, would require a greater electrical power consumption for larger motors. Thus, in the interests in power economy and in the enhanced survival of the antenna system, the use of a protective radome was specified as a necessary component of the facility. 2.1.2 Electronics Support Facility A key design goal of this remote facility is that the day- to-day tracking operations that require human operators to interact with equipment will be conducted remotely within the confines of McMurdo, proper. Thus, during normal operations and when alignments and maintenance is not required, the electronics support facility at the tracking site is unmanned. The architectural design for the support facility will reflect this general design goal with the square footage devoted to the facility. A single building of approximately ???? square feet will be required for an environmentally controlled electronics room, an electronics bench repair room, and limited storage. The support facility cannot be more than approximately 75 meters from the tracking antenna. This is a design constraint imposed by signal losses between the electronics in the support facility and the antenna, as specified by Scientific Atlanta. Another requirement for the support facility, mainly due to its close location to the tracking antenna, is that the roof of the support facility must be at, or slightly below, the zero degree reference elevation of the tracking antenna, and the support building must not block the view of the boresight facility. This building elevation constraint is to prevent the support building from blocking the low elevation horizon view of the tracking antenna. 2.1.3 Control Room Approximately 300 square feet have been identified as required for the equipment, office space, and personnel space for a maximum of three operators. This space will represent the day- to-day human interface to the entire tracking facility. This space will have a control computer and high density magnetic tape drives that constitute the remote control and data recording interface of the system. A location within the Albert P. Crary Science and Engineering Center (CSEC) has been identified, Room 205, as a suitable location for this application. The CSEC was specified as a location for the control room as it represents the focal point within McMurdo for scientific activity. It possesses many desirable attributes: an environmentally controlled atmosphere for sensitive electronic equipment, an advanced computer network, readily accessible computer technical support, an electronics shop and associated technical support, and controlled access. It is felt that the general type and scope of activity, as well as the end product being acquired (SAR imagery in support of science), was compatible in scope with the activities that the CSEC was designed to support. 2.1.4 Boresight Facility A routine pre-track operations procedure for this class of satellite tracking station is to calibrate and test the tracking and signal acquisition systems with a local, low power transmitter located on the ground and within line of sight to the main antenna. The final location of the main antenna will dictate the final location of this boresight facility. The basic requirements are that a small tower be erected to mount two small parabolic antennas, on the order of 0.7 meter in diameter, and be within a certain specified maximum cable run length to a small heated enclosure to house the transmitters and a telephone data modem for remote control via the local telephone system. The heated space needs not be more than the size of a small closet. A general limitation is that the boresight facility cannot be more than a few km distant from the main antenna, and the boresight facility cannot be any lower in elevation that approximately 3 degrees below the zero degree elevation reference of the main antenna. This is a design limitation of the antenna system provided by Scientific Atlanta. 3.0 General Site Selection and Criteria 3.1 Proximity The general operation philosophy required by NSF/OPP to drive the design of the RADARSAT system was that of the remote facilities, i.e. the tracking antenna and related electronics support building, would be operated remotely from within McMurdo, thus requiring no personnel continually man the site. However, it was acknowledged that personnel would typically have to go to the site on the order of 1 day per week for routine maintenance. Additionally, in the event of a system failure, personnel would have to commute to the site on a daily basis while troubleshooting and repairs were in progress, a length of time that can vary based on the nature of the problem, but a condition that could conceivable result in daily commuting be required for up to 14 days in duration, with on-site occupation extending up to 12-14 hours per day. The potential for a high visitation rate and lengthy daily stay during a repair scenario places a constraint on the distance from McMurdo town center that can be prudently accepted, especially in the case of winter operations. Past experience from the operation of outlying facilities such as the U.S. Arrival Heights Laboratory and the Cosmic Ray Observatory have indicated that there is risk of personnel becoming stranded at outlying facilities during winter storms, sometimes lasting 2-3 days in duration. Additionally, the roads become dangerous or impassible. A general design constraint was defined for proximity so as to minimize the risk to the safety of personnel that might be travelling to, and working at, the remote facility during the winter. Thus, general site selection criteria were defined as: (1) the remote sight should be on or close to established roads that can be maintained during the winter and (2) the site should be as close as practical to McMurdo town center. An additional reason for proximity, unrelated to personnel safety, is that of reasonable access for the delivery of electrical power and telecommunications utility lines. The utility services for the remote facility must be provided from McMurdo proper. Close physical proximity to McMurdo minimizes the expense, possible environmental effects, and land use conflicts from a very long utility run. 3.2 Initial Site Selection 3.2.1 Reference For initial reference purposes, a generic site located within the confines of McMurdo was examined for the suitability of the horizon. This was easily accomplished with horizon profile data on file within the USAP program for a location surveyed from a small satellite tracking antenna platform (the South Pole Satellite Data Link, or SPSDL) located on the roof of Building 165, the U.S. Navy administration and radio communications center building. This horizon data was passed to JPL for evaluation against their minimum elevation criteria. JPL indicated that this horizon profile was suboptimum, especially in regards to the critical azimuth to Pine Island Bay, which was almost completely blocked. JPL indicated that a site with this type of visibility would be a last choice. A site in or near Building 165 represents a typical best case horizon view from within the McMurdo urban area. This location is fairly centered with respect to the surrounding hills to the North and East. Additionally, it is about as far from the hills, displaced in the direction of the shoreline, as possible without reaching a local downslope that leads to the shoreline. This site was not seriously considered as a location for the RADARSAT tracking antenna for the following reasons: there is no existing open space that the antenna could be placed that would not have local buildings blocking the horizon view from close in, and the weight and structural dynamics of the tracking antenna, under the protective radome, would result in a much more expensive and difficult to construct installation if the antenna were built on an elevated tower, as opposed to the suggested design that would use precast concrete slabs and placing the antenna essentially at ground level. 3.2.2 Identification of Potential Sites Meeting the Proximity and Horizon View Criteria Given the impracticability of a McMurdo urban center installation, a review of contractor (Antarctic Support Associates) McMurdo vicinity plot plans was conducted to identify the following potential remote tracking antenna sites: (1) Summit of First Crater (boundary of Site of Special Scientific Interest No. 2, SSSI #2, Arrival Heights) (2) Crest of small knoll, no name, overlooking McMurdo and near the junction of the road turnoff that leads to Arrival Heights, a site proposed by the previous contractor, ITT/Antarctic Services, for a new explosives storage yard (3) A variant combination of either the existing HF Rosette receiving antenna site (a small knoll overlooking the existing explosives storage yard), or the plateau that hosts the existing explosives storage yard (4) Summit of Crater Hill (5) A site within Arrival Heights, SSSI #2, between the U.S. laboratory building and Second Crater (primarily to spot check horizon) No other locations appeared identifiable from available maps that had the appearance of meeting the criteria. During January, 1991, a preliminary physical site investigation was made of all four sites described above. The physical inspection consisted of a walk of the site to gain a familiarity with the presence of any indigenous flora or fauna, the nature of the soil, the actual proximity of access roads, the actual distance from McMurdo proper, any difficulties that site location might pose to heavy equipment needed for construction, existing land use conflicts, and salient horizon profiles. Following the physical site investigation, a memorandum for record was created that documented the findings as was used as reference material for subsequent discussions regarding site selection with various interested parties. A post survey discussion revealed the following assessments for the various sites: > All sites tended to possess reasonable horizon profiles with respect to JPL requirements. Some sites were better than others, most notably the summit of Crater Hill, which is the tallest point at the McMurdo end of Hut Point Peninsula. The summit of First Crater had the second best general view, followed by the unnamed knoll and the HF Rosette antenna knoll, in that order. > The HF Rosette antenna knoll/existing explosives storage yard had the best proximity to McMurdo, followed by the unnamed knoll, followed by First Crater, followed by Crater Hill. After an initial review, the following eliminations were made: > The summit of Crater Hill was eliminated because of its remoteness and because of physical access problems. A construction road would have to be built up a rather steep incline in loose soil/permafrost in order to gain access to the summit for the heavy construction equipment and long term access. It was noted that an original site for the ASR-8 surveillance radar was proposed for the summit of Crater Hill, and the ensuing on-site construction evaluation resulted in the current sitting on the southern slope of Crater Hill, well below the summit, within the maximum reach of a construction road that was extended from the HF Transmitter Site plateau to the base of the final ascent of the upper slope of Crater Hill. This was a pre-existing example of the practical limitation of construction at this location. > The summit of First Crater, or any site within the confines of SSSI #2 at Arrival Heights, was eliminated on a matter of general principles. It was felt that this could represent a possible conflict with the management plan for SSSI #2 adopted in 1974 by the Antarctic Treaty Consultative Members, as recommended by the Scientific Committee on Antarctic Research, as later amended and extended. Although the original purpose of the RADARSAT facility was of a radio frequency reception nature only, and thus falling within the general scope of the management plan, it was felt that the apparatus of the tracking facility itself and the possible future requirement to transmit would represent a conflict with the scientific research conducted within SSSI #2 should the facility be located within the boundaries of the SSSI. The remaining choices were the unnamed knoll and the HF Rosette/explosives site. A problem then existed with a review in progress regarding the outstanding recommendation to relocate the explosives storage site to the northern side of the unnamed knoll. The recommendation to relocate the site was under critical examination by the new NSF/OPP Safety Officer, beginning in the 1992/93 austral summer season. This review was assisted by an electromagnetic reconnaissance commissioned to characterize emissions from the ASR-8 radar and the electromagnetic environment at the U.S. Arrival Heights Laboratory, as well as selected sites in the hill line above McMurdo. A zero based review of the explosives requirements that drove the original design proposal for the new site was also under way. Until a final recommendation was reached for the future of explosives storage, both sites were tied up with respect to the RADARSAT project. The HF Rosette antenna knoll was eliminated as a possibility in that no presently known location was available for relocation of the antenna, and the antenna system could not be decommissioned, as it is the primary receiving antenna for Navy operations. By mid-year 1993, the NSF/OPP Safety Officer issued a finding that placed the long term location for explosives storage at the historical and current site, with directed modifications. This freed the unnamed knoll site to be the recommended location for the RADARSAT tracking facility. Coincidentally, this site also represented the preferred site by the NSF/OPP Electronics Engineer, the individual conducting the original site selection survey. 3.2.3 Salient Features of Unnamed Knoll This site possesses the following features: > the site has been historically used for the collection of fine fill material for general construction and road maintenance, as well as a processing (sifting) site for this work > consequently, the site is previously disturbed, to a high degree of significance, and has long lost its pristine condition > the summit of the knoll appears to have been reduced in elevation such that the site no longer possess its natural contours > the juxtaposition of the knoll peak and the adjacent terrain that slopes towards the north and east represent an ideal configuration for the requirement of the antenna to look above the roof line of the near-by support building and to possess an unobstructed view in the azimuth of Pine Island Bay; the natural contour permit this with a minimum of earth work and permit the antenna foundation design of choice - concrete slabs at ground level > the site is immediately adjacent the main access road that rises out of the McMurdo urban area and leads to the U.S. Arrival Heights Laboratory; thus the road is maintained during the winter for access to Arrival Heights, and is travelled for other purposes on a routine basis all year around > the site is within close reach to an existing electrical power and telecommunication utility run that extends from the McMurdo urban area to the U.S. Arrival Heights Laboratory; this will permit a reduction in construction costs and will permit the co-use of an existing utility run to minimize the additional utility lines that must be run to the site > the site affords an unobstructed view to the existing facilities (Buildings 87/89) on the side of Observation Hill, such that the Observation Hill facilities can be used as a boresight facility; the look angle depression and the line of sight separation fall within acceptable parameter limits as set by NASA and Scientific Atlanta; because of the use of the existing facilities and utility support of the Observation Hill facilities, the installation and cost of the boresight facility becomes negligible 4.0 Other Defining Criteria 4.1 Antenna Size and Power Requirements The RADARSAT space-ground telemetry data rate of 105 megabits/second, plus the orbital altitude of approximately 750 km, determines the general antenna size and associated electromechanical tracking mechanisms. The proposed ground station antenna system and support electronics are provided by NASA, Wallops Flight Facility Code 800, via a contract with Scientific Atlanta of Atlanta, Georgia. A 10 meter diameter antenna represents a practical and reasonable engineering choice for the RADARSAT mission and the typical satellite tracking operations that the facility may be desired for in the future. The tracking of low earth orbit polar satellites requires the antenna to have the capability to slew at high rates when tracking a satellite that passes near zenith. This creates a large electrical power demand to slew such a massive antenna at the requisite rate. NSF/OPP required NASA to consult with Scientific Atlanta to devise a means to reduce the power demands of the antenna tracking system during active tracking as much as possible. A solution devised by Scientific Atlanta was to modify the existing two motor tracking antenna (elevation and azimuth) by adding a third motor (elevation tilt). This is a common technique used for high slew rate tracking systems that can increase performance (ability to keep up with fast moving targets) and to decrease power demands. This is accomplished by using the third motor, which operates at low rate, to induce a tilt in elevation to reduce the rate at which the elevation motor has to turn. The net effect is a reduction in the power consumed by the tracking system. 4.2 Unattended Operation of the Remote Facility A main operations criterion of NSF/OPP was the ability to operate the remote facilities from within the confines of the McMurdo urban area for the routine day-to-day activities that are human interaction intensive. To respond to this requirement, NASA directed Scientific Atlanta to modify the existing earth station systems to be provided such that full computer control of satellite tracking, operations scheduling, pre-pass calibration, and data recording would be possible remotely. This has lead to a design such that the control computer can be interfaced to the McMurdo Internet computer network link to the outside world, and a technician can actually access the McMurdo tracking computer from the United States to assist in maintenance and troubleshooting. The provision of the remote control of the tracking facility has not only produced a safer operation, it has also enabled the total number of on-site operations/maintenance personnel recommended by NASA to be reduced from 5 to 3. 4.3 Construction Techniques The design of the remote electronics support facility was under the cognizance of NSF/OPP and its prime contractor, ASA. The general design and construction philosophy taken for this structure was that of prefabricating the building in the U.S. and having the building constructed into modular sections that would permit a rapid erection of the structure with a minimum of on- site construction activities (when contrasted to the effort expended for a typical building constructed on-site from raw materials, the so-called "stick-built" building). This technique minimizes the number of construction tradesmen needed for the construction and completion of the facility, and it minimizes the time required, and thus local environmental impact.