SIR-C / X-SAR 1-2 and SRTM
Satellites for Earth Observation today have an increasingly important role for the protection of the environment, the prevention of natural disasters, homeland security and citizens.
The ASI is committed to this industry first with the satellite system COSMO-SkyMed, the largest space program ever undertaken by Italy, and other important missions of scientific and application.
These two missions for Earth Observation were planned and carried out in a collaborative program between ASI, NASA and DARA (name at the time German Space Agency, DLR today). The first, lasting 10 days, was held in April 1994; while the second, lasting 12 days, in the autumn of the same year.
These two missions have represented a significant step forward in the use of advanced radar image (L-band, C and X), carried into orbit by the Space Shuttle, allowing, thanks to sophisticated instrumentation, to further deepen the knowledge of the Earth’s surface. In particular they have provided the first opportunity to produce radar images from space using data in different frequency bands; the first high-resolution image sensor installed on the space platform that uses data multipolarization; the first multiparameter radar image, which provided coverage in different seasons.
The activities of competence ASI for the part of data processing of the first two missions, were the following: “screening” and processing in a survey of all raw data in X band acquired during the mission, precision processing of the raw data, geocoding precision, generation of additional products such as: “raw-data” annotated on CCT, SAR images in complex format (real and imaginary part, registered products multifrequency and multi-temporal; experimental products interferometric, provision of services both to other processing centers (JPL and D-PAF) that towards the scientific community involved in the mission (including the activities relating to inventory, storage and distribution of data and products generated).
The number one NASA Daniel Goldin declared in 1994 that the two missions had a resonance in the US second only to the landing on the moon.
With the Shuttle Radar Topography Mission (SRTM), the Italian Space Agency, NASA and DARA have extended the collaboration begun in 2000 with the missions SIR-C / X-SAR in 1994. SRTM has indeed used (six years later, in 2000) the same instrumentation of the two previous experiments, as amended. The goal was to measure the topography of the land surface. The data acquired with the tools of SIR-C, were processed to generate new data in height with a vertical accuracy of about 16 meters with a second of arc of latitude and longitude. The interferometer X-SAR has provided non-contiguous data with an accuracy of about 12 vertical meters. ASI attended the SRTM providing some subsystems of radar instrumentation, hardware and software for the control system, a processor interferometric “quick look “and updates of the processors of the I-PAFF. The Shuttle Radar Topography Mission (SRTM) obtained elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth. SRTM consisted of a specially modified radar system that flew onboard the Space Shuttle Endeavour during an 11-day mission in February of 2000. There are three resolution outputs available, including 1 kilometer and 90 meter resolutions for the world and a 30 meter resolution for the US. GLCF serves the main USGS editions, plus it has boosted editions as well as provides editions in WRS-2 tiles to approximate Landsat scenes.