EARTH OBSERVATION SATELLITES
SAR-Lupe
_The SAR-Lupe is a high resolution space-based Synthetic Aperture Radar (SAR) network developed by EADS for the German Ministry of Defense. The SAR radars feature a 3 meters long antenna with a folding probe which provides radar imagery with one 1 meter resolution in all weather conditions.
The satellites operate in 500-kilometre orbits. They use an X-band radar with a three-metre dish, providing a resolution of about 50 centimetres over a frame size of 5.5km on a side ('spotlight mode', in which the satellite rotates to keep the dish pointed at a single target) or about one metre over a frame size of 8km x 60km ('stripmap mode', in which the satellite maintains a fixed orientation over the earth and the radar image is formed simply by the satellite's motion along its orbit). Response time for imaging of a given area is ten hours or less, making it one of the fastest available systems.
The satellites operate in 500-kilometre orbits. They use an X-band radar with a three-metre dish, providing a resolution of about 50 centimetres over a frame size of 5.5km on a side ('spotlight mode', in which the satellite rotates to keep the dish pointed at a single target) or about one metre over a frame size of 8km x 60km ('stripmap mode', in which the satellite maintains a fixed orientation over the earth and the radar image is formed simply by the satellite's motion along its orbit). Response time for imaging of a given area is ten hours or less, making it one of the fastest available systems.
TerraSAR
_The satellite has been built on an octagonal structure about 5.2 meters
long and 2.2 meters in diameter. The launching weight is around 1,000
kilograms including its radar instrument. The active radar antenna is
4.8 meters long and 0.8m wide. The active antenna coupled with the
satellite orbit ensures that the observation system is able to image any
point on earth within three days. The Synthetic Aperture Radar (SAR)
operates in three modes: spotlight mode, strip-map mode and scan SAR
mode.
In spotlight mode the SAR antenna covers a 5-10 by 10 kilometers area with the maximum resolution of one meter. In strip-map mode the observation system sweeps an are of 30 kilometers by a maximum of 1,500 kilometers long with a resolution of three meters. In scan SAR mode the antenna uses a 16 meters resolution to sweep a corridor of 100 kilometers wide and a maximum length of 1,500 kilometers. Additionally, an experimental mode allows to divide the antenna in two independent parts of each other to identify moving ground objects/targets such as ships or cars.
In spotlight mode the SAR antenna covers a 5-10 by 10 kilometers area with the maximum resolution of one meter. In strip-map mode the observation system sweeps an are of 30 kilometers by a maximum of 1,500 kilometers long with a resolution of three meters. In scan SAR mode the antenna uses a 16 meters resolution to sweep a corridor of 100 kilometers wide and a maximum length of 1,500 kilometers. Additionally, an experimental mode allows to divide the antenna in two independent parts of each other to identify moving ground objects/targets such as ships or cars.