STARRS Calibration and Noise Issues for EuroSTARRS

摘要

The airborne remote sensing by STARRS provided L-Band brightness temperature data for land and ocean survey regions of the EuroSTARRS campaign. STARRS is a new instrument, and determining its performance and techniques for its best use are crucial to its development as a leading edge L-Band microwave system. We have summarized the calibration improvements and adjustments performed for the EuroSTARRS STARRS data. This includes improvement of the pitch and roll data, and the ocean and sky calibration of STARRS. We have also demonstrated the characteristics of the noise in STARRS, particularly the 1/f character of the noise. Work is underway to improve the performance of STARRS based on this analysis. We detected both large and small environmental sources of L-Band energy during the Casablanca flight. When the beam swath pointed toward Barcelona during circling flights, a very large source was detected on all beams. The effect of this and other similar sources on airborne and satellite passive L-Band systems may be substantial. A second environmental effect was that higher brightness temperatures were observed at high altitude than at low altitude for the repeated east-west line of the survey. We have tentatively concluded that this is due to detection of man made sources at the horizon, but cannot distinguish between a general 'glow' and a point source viewed obliquely. These observations of man made sources of L-Band energy may, if confirmed, have substantial effects on other airborne L-Band surveys and on satellite operations.