Medspiration â System Requirements Document - Data User Element

More documents

Recommendations

Info

Medspiration MED-SOC-RS-001_1 System Requirements Document Issue F Page Table, fig. Reference ID Text from reference documents SR entry provide a data product suitable for use by GHRSST-PP data analysis systems and ocean model data assimilation schemes, the conform to the GODAE data sharing project. 33 GDS-061 L2P data products are the lowest-level, common format data products produced by the GHRSST-PP and provide the NASR “building blocks” for all other higher level data products. 33 GDS-062 Each L2P data product contains original SST measurements together with confidence fields and an error estimate (called SSES and described ion the following paragraphs). L2P data products consist of the original SST measurements (that are not re-gridded or modified) together with additional confidence and error estimates. L2P.0030 L2P.0040 L2P.0050 33 GDS-063 A separate L2P data product is produced for each sensor at each RDAC. L2P.0070 33 GDS-064 Operational users that have requested this type of SST data product (see the Medspiration User Requirements Document SYS.2050 (URD), available from the GHRSST-PP Project Office) may access L2P data products directly in real time from RDAC and GDAC. 33 GDS-065 In addition, L2P data products provide a direct input to the GHRSST-PP Reanalysis project (Casey et al., 2003) and form NASR the principal data archive for the GHRSST-PP. 33 GDS-066 A bias and standard deviation (sd.) error estimate is required for each [pixel] measurement before SST data originating L2P.0050 from different sources can be properly assimilated into ocean model systems or analysed together to provide new SST data products. Assigning error estimates to SST measurements is a fundamental requirement of the GDS. Two types of error assignment are possible within a L2P data set: 33 GDS-067 1. Error estimates provided by a data provider as part of the L2/L4 input data L2P.0050 33 GDS-068 2. Statistical error estimates calculated from a match up database containing satellite and drifting/moored buoy in situ SST L2P.0050 observations. 33 GDS-069 In the case of (2), there are clearly insufficient buoy observations to assign a unique error estimate for every satellite NASR measurement and instead, the available data spanning a particular time-window must be used to assign a statistical error © 2004 SOC Page 122 of 193
Medspiration MED-SOC-RS-001_1 System Requirements Document Issue F Page Table, fig. Reference ID Text from reference documents SR entry estimate. This is performed as a four stage process (WP-ID3 in Figure 3.1.1): 34 GDS-070 1. A quantitative “confidence value”, having a value spanning 0 (no data, measurement is sea ice) to 5 (highest confidence in the SST measurement), is derived for each pixel measurement based primarily on an estimate of the surface wind L2P.0040 CFD.0010 speed, proximity to other cloud contaminated/rain contaminated pixels and, proximity to a SST reference climatology. Confidence values are optimized for likely errors from each sensor type (MW and IR). 34 GDS-071 2. L2P observations are then matched to near contemporaneous quality-controlled in situ SST observations in situ data SYS.0060 and the resulting data record (together with any additional auxiliary data) are stored in a relational database system called the GHRSST-PP Match-up Database (MDB). 34 GDS-072 3. Error estimates for each SST measurement are then derived by analysing the MDB for a given time window (e.g., 1 Out of scope week, 1 month, etc.). For each sensor and for each confidence value (1-5) a Sensor Specific Error Statistic (SSES) is produced (i.e., for each sensor and confidence value all data are analysed to compute a mean bias and standard deviation). 34 GDS-073 4. The SSES bias and standard deviation computed in (3) above is then assigned to all [sensor specific] L2P data having L2P.0050 an equal confidence value. 34 GDS-074 The format of data records held within the MDB is described in Appendix A4 and has been designed to be compatible with format other SST MDB (e.g., the Miami pathfinder MDB) in order to take advantage of these data and to further contribute to their development. 34 GDS-075 GHRSST-PP L2P data products will serve the requirements of some operational ocean modelling groups in real time. SYS.0100 34 GDS-076 However, many user applications and operational modelling groups request complete SST fields, free of gaps caused by NASR clouds, rain or lack of data coverage, at regular intervals of between 6 and 24 hours. 34 GDS-077 Most users require an estimate of the sub-surface SST field that is free of diurnal variability (the SSTfnd) that cannot be NASR directly measured using current satellite techniques. © 2004 SOC Page 123 of 193
Page 1 and 2:
Medspiration System Requirements Do
Page 3 and 4:
Page 5 and 6:
Medspiration MED-SOC-RS-001_1 Syste
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72: Medspiration System Requirements Do
Page 73 and 74: Medspiration MED-SOC-RS-001_1 Syste
Page 121: Medspiration MED-SOC-RS-001_1 Syste
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193:
show all

Medspiration â System Requirements Document - Data User Element

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?

Medspiration â System Requirements Document - Data User Element