SOAR Cellular Ocean Altimetry / Scatterometry Technology (COAST), Phase A-2

PI: Yunck, Thomas (GeoOptics)
Co-PI(s): Palo, Scott (University of Colorado) : Saltman, Alex (GeoOptics)
Start Year: 2021 | Duration: 1 years
Partners: GeoOptics, University of Colorado

Project Abstract:

COAST seeks to realize a variety of advanced monostatic and bistatic ocean radar functions, including scatterometry and altimetry, in pairs or clusters of small satellites. While the Phase A-1 study has matured the baseline COAST mission design it has not permitted a full exploration of the design possibilities. There are various design details that need refining as well as additional system validation tasks that will lower risk and help prepare for a successful implementation. In addition, several concepts for additional
applications and functions emerged in the course of Phase A-1 that should be evaluated before proceeding with a detailed design and implementation.

Specifically, an emerging application of space radar from LEO, the measurement of soil moisture, was recently added as a target for the NOPP/SOAR Cohort-2 round. The COAST team therefore proposes to add soil moisture as a new target measurement in Phase A-2 and do the necessary analysis to characterize the nature and quality of the observations we might make and to assess what, if any, design adjustments might be desired to include the soil moisture application.

In addition, the phase A-1 study identified a potentially promising path to fundamentally increase the radar system capability – specifically, to augment the design to enable each spacecraft to recover individual monostatic SAR images from the radar returns. This
could enable the combining of two concurrent SAR images to perform interferometric SAR, or InSAR, wide-swath altimetry, as is planned for NASA’s upcoming $1.3 billion SWOT mission. The result would be few-centimeter ocean altimetry from InSAR images with 10-20 meter surface resolution over swaths tens of kilometers wide, meeting all basic observing requirements set out in the NOPP/SOAR BAA at a small fraction of the SWOT cost. The practicality of this enhancement is not yet well understood and must be studied in greater detail.

The individual tasks proposed for the Phase A-2 study include:
• Build and test antenna brassboards at one or both frequencies.
• Build and test prototype transmitter electronics
• Perform detailed instrument and spacecraft thermal analysis and design
• Explore propulsion options, if needed
• Perform SAR/InSAR design upgrade analysis
• Develop detailed onboard radar processor software design
• Analyze COAST design/performance for soil moisture measurements
• Demonstrate functioning Cion radar processor
• Develop ground processing software design
• Add more detail to earlier PDR material
• Conduct a delta-PDR

BAA: N00014-21-S-B001