| Popis: |
Undertaken by the European Space Agency (ESA-ESTEC), HIRIS (high resolution imaging spectrometer) instrument study program includes signal processing and instrument overall data handling design concept. HIRIS is an hyperspectral imager to be implemented on a low earth orbit type satellite. The instrument is a pushbroom operating around 800 km altitude sun-synchronous orbit with 40 m sub satellite spatial sampling, 30 km swath variable by plus or minus 30 degrees and a spectral coverage from 450 nm to 2350 nm at 10 nm average spectral sampling. One of the major critical areas is therefore to develop, manufacture and integrate a full detection chain, including front-end electronics, preamplifiers and video chains (analog processing), and radiometric correction devices and compression algorithm implementation (digital processing). Taking into account imaging mission and system constraints, a data handling architecture has been selected, based on the video processing standardization, what ever the focal plane design is. The off- line processing architecture leads to an optimization of the budgets while integrating the overall digital processing imposed by mission performances fulfillment. With an input data flow near 320 Mbps, the overall data handling delivers through the output formatter a 100 Mbps data flow to the ground after having performed the required on board processing (gain correction, offset correction, needed compression and encoding implementation). |
