The MRI Collaborative: Development of Monitors for Alaskan and Canadian Auroral Weather in Space (MACAWS) was designed to be a sensor web network providing both real-time and historical GNSS TEC and scintillation data products.  These data are needed for geospace science and space weather monitoring in the currently unsampled or under-sampled auroral and sub-auroral regions in North America (Alaska) and North-western Canada. These regions are significant as they are the locations of origin for the majority of space weather events that affect the United States. Alaska is rapidly expanding in both commercial and DOD operations, and GNSS infrastructure is needed to aid in monitoring space weather events, such as the recent May and October storms (see Figure).  During these storms, much of the FAA’s WAAS system was affected, and understanding how and why is one of the motivations of the research enabled by these observations.  The MACAWS project had as its mission statement:  “To develop instruments capable of measuring system properties necessary to examine the coupling mechanisms and complexity within the space atmosphere interaction region.” 

MACAWS was designed to monitor the scintillation of GNSS signals and the ionospheric total electron content at various locations throughout Alaska and Canada.  GNSS scintillation refers to rapid, short-term fluctuations in the amplitude and phase of received GNSS signals.  These fluctuations are introduced to the signal as it travels through the Earth’s ionosphere,  the region from about 60 km to 1000 km filled with charged particles and neutral gases,.  It is a region of about 1015 million cubic km (40,000 times the volume of Earth) where solar-magnetosphere driven processes interact in  the near-earth space environment.  It is also the region that strongly impacts radio communication and navigation.  To illustrate this, when the GNSS signal leaves a GNSS satellite, it is coherent, meaning both its phase and amplitude are stable, varying in a way that is predictable.  But as it travels through the ionosphere to the ground, if there are irregularities in the ionospheric electron density, these can introduce fluctuations in both the phase and amplitude of GNSS signals.  Under certain conditions, loss-of-lock can occur, essentially making it impossible for the ground-based receiver to track the GNSS satellite.    These fluctuations lead to positioning errors and signal degradation. Improving our understanding the causes of high-latitude scintillation and the formation of ionospheric  irregularities is one of the motivations of gathering the MACAWS data.  At high latitudes, the ionospheric phenomena of interest include:  aurora, polar patches, traveling ionospheric disturbances and storm enhanced density–all of these phenomena are readily observed in electron content measurements.  The primary goal of MACAWS is provide a ground-based sensor web network that provides both real-time and historical GNSS ionospheric data products for use in geospace science and space weather monitoring in currently un-or under-sampled auroral/polar regions in North America. The MACAWS project provides important contextual information about the multi-scale physics behind the formation of these irregularities and the ensuing scintillation.

The MACAWS project purchased 35 specialized GNSS receivers capable of monitoring both GNSS scintillation and the ionospheric total electron content along the line of sight to each GNSS satellite in view.  Of these receivers, 10 were sent to Canada, 22 were sent to Alaska, 1 was sent to Puerto Rico, 2 remained at Haystack, 1 as a MACAWS station at Haystack, and 1 as test system.  These receivers track both the GPS and GLONASS constellations and compute TEC and scintillation statistics for the acquired datasets.  The setup was for all fielded sites to send data back to a central server at Haystack.  These data are gathered and processed and hosted in the NSF CEDAR Madrigal database (https://cedar.openmadrigal.org/).  A global scintillation product has been developed within Madrigal and all scintillation products are available through Madrigal.  The MACAWS TEC data is included in the Madrigal TEC global maps. 

One of the long-term results of the MACAWS project has been the design and improvement of the installation of these specialized GNSS receivers in remote environments.  For example, in our initial deployment there were multiple difficulties with internet connections.  We are now looking to upgrade (under separate funding) several of our remote sites with STARLINK modems.  We have fielded one MACAWS-like unit to South East Asia to monitor scintillation.   Three units are being installed in Antarctica, two of which are already operational.  Again, all of these units have been separately funded by different agencies.  However, each of these units takes advantage of the data processing pipeline set up to enable the total electron content and scintillation data to be hosted in the Madrigal data base.  By adding important capabilities to help meet growing demands for space-weather information, the MACAWS project has had significant broader impact. 

Last Modified: 04/07/2025
Modified by: Anthea J Coster