AlSAT-1 is part of an international (BNSC-UK, China, Nigeria and Thailand) disaster-monitoring constellation (DMC) of 6 micro-satellites dedicated for monitoring disasters throughout the earth, such ... as floods, fires, earthquakes, volcanoes, large-scale industrial accidents and civil strife. When there are no disasters, AlSAT-1 will be used for Algerian purposes such as monitoring desertification, industrial and marine pollution, agricultural monitoring, geophysics mapping and fire detection. The nature of the mission is that the 6 micro-satellites, when coordinated together, can produce a daily revisit with a 32 m resolution multi-spectral imaging and 600 km ground track. AlSAT-1 uses the flight proven modular SSTL bus from previous missions but will carry a push broom imager for the first time on SSTL micro-satellites. As a part of the constellation and to maintain a daily coverage, AlSAT-1 is equipped with a propulsion system for orbit corrections.
AlSAT-1's main payload a multi-spectral earth observation imager. Digital store and forward communications can be experienced between two points and autonomous GPS positioning techniques also accomplished.
The Algerian satellite is one of SSTL’s new generation microsatellites in a sense that it carries a new type of push broom sensors. These types of sensors can previously only be found in larger commercial satellites. Because of the advance in electronics and semiconductor integration on a single chip, nowadays these sensors are being implemented by SSTL on microsatellites.
AlSAT-1 is designed to view the earth surface with a 32 m resolution in three spectral bands (R, G, NIR) and a ground track of 600 km. The spectral bands were chosen to correspond to those used by commercial satellites in the following wavelengths (in micrometer) 0.5-0.6 micrometer, 0.6-0.7 , 0.7-0.8 ). The imaging system comprises two cameras for each spectral band and two sensors with 10 000 pixels each. This represents a huge quantity of data for the electronics on board (processors, SSDR, fast clocks) to deal with.
The cameras provide 32 m ground resolution in 3 spectral bands capable of giving detailed information on earth resources, land use and effects of pollution and natural disasters using 2x10 000 pixels linear array detectors digitized to 8 bits radiometric resolution (256 levels). The image swath width is 600 km and the imager can collect images continuously along the flight track. The images are stored on board the microsatellite via the On Board Computer (OBC) and Controller Area Network (CAN) in the 2x512 Mbytes Solid State Data Recorder (SSDR) for later transmission to ground via digital packet error controlled links at 8 Mbit/s in S-band.
However, on the satellite there will be an option to do “windowing”. By using this technique, we can take images of 100x100 km and thus extend the track range.