A Novel Low-cost, Ka-band, High Altitude, Multi-Baseline Unmanned Aerial Vehicle Sensor for Surface Water Ocean Topography

The KaSPAR and its technology also fill technology gaps that exist in several other commercial and governmental applications. US Coast Guard and US Geological Survey have expressed interest in using KaSPAR to build such a data base for high use (recreational and navigation) rivers. This would improve the performance of models used to predict discharge rate and flow patterns of rivers that use stage level data from in situ river gauges, and in the future, from SWOT elevation. In turn, this would aid navigation and would provide critical information to search and rescue operations. KaSPAR could also be deployed rapidly during time-critical events such as flooding, or to provide storm surge spatial measurements prior to land-fall. Ka-band interferometry has the potential to provide 3D mapping of scenes during limited low visibility conditions (i.e. fog, drizzle, etc). The technology developed for KaSPAR may be used to realize Ka-band radar interferometer electronic vision systems that would complement existing infrared systems. The aircraft industry has expressed significant interest in this area. Although designed for mapping rivers and oceans, a KaSPAR system could be used to provide 3D terrestrial imaging. However, it is significant that the high-bandwidth phase-stable multichannel architecture and processing techniques are applicable and transferable to other geometries (for example off-nadir viewing for dedicated terrain mapping).

In contrast with previous implementations at lower frequencies (L-, C- and X-band), millimeter-wave interferometry (Ka-band for KaSPAR) enables improved accuracy with a constrained antenna and baseline size. These advantages make the KaSPAR development applicable to potential solution for interplanetary ice mapping missions (e.g. Europa) and planetary topography mapping missions. KaSPAR componentry, integrated subsystems and techniques including the phase-stable receivers and calibration methodologies could readily be integrated, or adapted for specific system requirements. A key element of KaSPAR is that it will utilize a solid-state power amplifier (SSPA) (rather than a tube amplifier). The 40W state-of-the-art SSPA KaSPAR will use would enable an operational airborne ice-surface topography mapper that would not only improve performance over that previously achieved, but also be capable of operating on long-range UAV's to enable ice surface topography mapping of remote, yet critical regions of Antarctica. This is highly relevant to NASA's ongoing IceBridge activities. More »