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ASAR Wide Swath Complex Products Implementation in PF-ASAR. B. Rosich. ASAR Wide Swath Complex Product. ASAR WS complex product were initially not foreseen as standard ESA products. ESA ASAR integrated processor (PF-ASAR) is therefore not capable of generating ASAR WS complex products.
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ASAR Wide Swath Complex Products Implementation in PF-ASAR B. Rosich WSS User group meeting – Frascati 5 Nov 2003
ASAR Wide Swath Complex Product • ASAR WS complex product were initially not foreseen as standard ESA products. • ESA ASAR integrated processor (PF-ASAR) is therefore not capable of generating ASAR WS complex products. • An ASAR WSS prototype has been developed by Polimi/Poliba under ESA contract and prototype products have proven to be extremely interesting for different applications. • Wide distribution of the new product to users requires it is integrated in PF-ASAR and provided as an additional standard ASAR product. • WSS integration in PF-ASAR, based on Polimi prototype, has been initiated in September 2003 and it is expected to be completed in August 2004. • Integration of an additional product in PF-ASAR requires as well an upgrade of other PDS facilities, the product specifications and several user tools. WSS User group meeting – Frascati 5 Nov 2003
ASA_WSS_1P Main Properties • ASAR WSS will be a non-stripline product • ASA_WSS_1P product format will conform with the ENVISAT product specifications with small differences. • ASAR WSS will be a complex product 16 bit I, 16 bit Q • Output imagery will be separated into bursts and sub-swaths. Line numbers will be reset to 0 at the start of each sub-swath and the time of the first line will be made the same for all swaths.. • Data will be sampled in a common grid both in range and in azimuth. • Product length / pixel spacing limited by the 2 GB size limit imposed by the ENVISAT PDSS. WSS User group meeting – Frascati 5 Nov 2003
ASA_WSS_1P Quality Requirements • Doppler accuracy < 25 Hz • Range spacing : 1/Fs, where Fs is the range sampling frequency for all sub-swaths • Azimuth spacing: TBD • Standard IRF requirements: • SSLR < -25 dB, PSLR < PSLRtheor.+2.5dB, ISLR < ISLRtheor.+2.5dB, Az.Res. < Az.Res.theor.+10%, Rg.Res. < Rg.Res.theor.+10% • Phase preservation requirements: • Ceos offset test: phase standard deviation < 10 deg. & mean phase < 0.5 deg • No artefacts in phase difference image • Phase preservation from burst to burst and swath to swath. WSS User group meeting – Frascati 5 Nov 2003
ASA_WSS_1P: TBD settings • Maximum product duration and pixel spacing • Product duration of 60 sec. & az. pixel spacing = 40 m >> 2 GB (~3.5GB) • Product duration of 30-35 sec. & az. pixel spacing = 40 m < 2 GB • Product duration of 60 sec. & az. pixel spacing = 80 m < 2 GB • Elevation antenna pattern correction: TBD • Azimuth and range windowing: TBD • Slant to ground range conversion: TBD • Zero Doppler correction: No (TBD) WSS User group meeting – Frascati 5 Nov 2003