System Requirement Document (SRD) - H-SAF

H-SAFSystem Requirement DocumentDoc. No: SAF/HSAF/SRD/2.1Issue: Version 2.1Date: 20/06/2008Page: 23/102Snow detectionby opticalbands2 km95 % probability ofcorrect classification6 h(dependingon latitude)2 hNOAA(AVHRR)+MetOpEffective coverby optical andMW bands, withflag for wet/dry10 km (in MW)5 km (inVIS/SWIR/TIR)15 % (depending ontarget size andcomplexity)6 h(dependingon latitude)2 h(AVHRR, ASCAT)+Meteosat(SEVIRI)+EOS-Terra/AquaMetOp(AVHRR, ASCAT)+Meteosat(SEVIRI)(MODIS)++NPOESSDMSP(VIIRS, MIS)Snow WaterEquivalent byMW radiometer+ scatterometer10–25 km ~ 20 mm6 h(dependingon latitude)2h(SSM/I, SSMIS)+EOS-Aqua(AMSR-E)++MW radiometersof the GPMconstellationQuickSCAT(SeaWinds)Table 2 Satellite-derived H-SAF products and satellite data sourcesIn addition to satellite-derived products, H-SAF will make available forecast productsderived by a NWP limited-area model, so that end-users have available a back-up productat any time. The targeted forecast products are shown as follows (Table 3).Forecast products Resolution Accuracy (long term > 2010) Cycle DelayInstantaneousprecipitation rateat the groundAccumulatedprecipitationMid-project: 7 km,end-project: 2.5 km10-20 % (> 10 mm/h)20-40 % (1-10 mm/h)40-80 % (< 1 mm/h)10 % over 24 h, 30 % over 3 h.Mid-project: 3-6h,end-project: 1 hFixed timesof the dayTable 3 Backup products generated by a NWP modelThe Development Phase, in addition to including the activities for developing andgenerating new satellite-derived products, includes a Hydrology validation programme,performed by “Cluster-4”, lead by Poland; this aim shall be achieved through a complexset of activities and working programs, fully explained in details in the Project Plan [AD 2]