Test evolution: RADARSAT-1 to RADARSAT-2
Test methodology for large spacecraft like RADARSAT-1 and RADARSAT-2 has been modified over the last decade resulting in changes to test environments. These changes in the required test environment have necessitated improvements in the test configuration modelling, instrumentation, and data acquisition systems. This paper will identify the significant changes and how the RADARSAT-2 assembly integration and test program has implemented these improvements.
Assembly, Integration, and Test Methods for Operationally Responsive Space Satellites
Abstract : Current government and industry standards in spacecraft testing result in an Assembly, Integration, and Test (AIT) timeline greater than six months. These standards will not support the vision of Operationally Responsive Space (ORS) to deploy a satellite within six days to fill an urgent need. Using the Air Force Research Laboratory's Plug-and-Play Satellite (PnPSat), multiple Rapid AIT trials were conducted. By exercising the AIT process with various spacecraft configurations and personnel, methods for reducing or modifying traditional testing regimen were investigated.
An Analysis of RADARSAT2 SAR-GMTI Performance for Standard Beam Mode
Abstract : Canada's RADARSAT2 (R2) commercial SAR satellite will have an experimental operating mode that will allow ground moving target indication (GMTI) measurements to he made with received data. This mode is also called MODEX (Moving Object Detection Experiment). In the GMTI or MODEX mode of operation, the spacecraft's radar antenna is partitioned into two apertures that sequentially observe the scene of interest from the same points in space. Data is simultaneously and coherently received from both apertures and is down-linked in parallel channels for processing to extract moving target radial speeds in their SAR image context. This paper provides an analysis of SAR-GMTI performance at the R2 Standard Beam Mode based on computer modeling and simulations. Two SAR-MTI processing approaches are being explored. One utilizes the classical DPCA clutter cancellation technique to provide sub clutter visibility for dim slowly moving targets. The other is based on the along-track (temporal) SAR interferometer technique, where amplitude and phase information of the slow-moving targets are exploited to allow their extraction from the dominant clutter background. Performances of the two approaches are compared. Effects of target signal contamination by background clutter is also examined. The results indicate that the two processing approaches are similar in their GMTI performance.