Mission Operations Overview
PRISM was programmed for repetitive, global-scale observations, and like AVNIR-2 and PALSAR, the observation strategy implemented aimed to maintain both spatial and temporal consistency over regional scales. The timing of the regional observations had been determined based on cloud statistics, seasonality and sun elevation, although cloud cover inevitably limited the amount of useful data acquired.
The default mode for PRISM operations is the 3-telescope triplet mode to enable along-track stereo viewing. As the swath width in triplet mode is 35 km, two 46-day cycles are required to achieve a full regional coverage, during which the instrument is tilted alternately (+/- 1.2° ) in across-track direction.
• Odd cycle numbers: +1.2° viewing angle
• Even cycles: -1.2° viewing angle
Some area will be operated by 2-telescopes observing mode (nadir 70km + backward 35km) based on the users requirement.
For detailed views of which regions were scheduled for acquisitions by PRISM, please refer to the PRISM Acquisition Plan.