1. Space Standardisation WS, ESRIN 15-02-2008
Generic Environment for
Cal/Val Analysis
Space Standardisation WS, ESRIN 1

2. GECA project description
GECA = Generic Environment for Cal/Val Analysis
This ESA project consists of two distinct, but connected activities: 1. evolution of ESA’s validation data centre, 2. definition of quality information & action protocol.
Item 2. Involves a MMI and HMI mechanism (server, libraries) to exchange product anomaly information (and corrective actions) towards end users and their tools
The following slides will only address item 1.

3. GVDC description - objectives
Generic Validation Data Centre (GVDC) objectives:
Harmonisation of correlative data standards
Access to satellite data centres
Access to correlative centres
Support Collocation
Support Intercomparison
Assist correlative data submitters

4. GVDC – Satellite Data Access to satellite data
- Users can query and retrieve subsets of EO satellite data (HMA), now only ESA EO data,
Generic, i.e. access to data from multiple domains (see table),
Still TBD whether we can also cover future/planned observations

5. GVDC – Correlative Data
Access to correlative data
Cal/Val data covering correlative data for multiple EO domains (see previous slide)
- Data Centre Inter-operability (see Table)
- Prototype working for exchange of catalogue meta-data (GML & OAI-PMH )
- Next step is exploring data exchange

6. GVDC – Collocation engine
Query for collocated pairs
user can set criteria to match a satellite with a correlative dataset,
Correlative can be a. another satellite product b. measurement from a non-satellite platform (e.g., ground-based, air-borne, ship borne) c. related to a fixed site

7. GVDC – Intercomparison support
Users can directly perform intercomparisons based on ‘best practice’ analysis functions
Pre-processing stages will bring collocated data into a comparable state, including, e.g., a. conversion of paired data to a common format, b. inclusion of auxiliary data (e.g., meteorological parameters from ECMWF), c. parameter conversion (e.g., mixing ratio to concentration), d. regridding and smoothing of data
This functionality will be available both on a server and as a toolbox

8. GECA EO GML suggestions
Support Limb looking products - “Envelope” information is most important, profile information is additional
Support Radar altimeter products (low-res line)
Add information on the Physical Quantities that are measured (Physical quantity classification)
Potentially add information on wavelength spectra (minimum and maximum or list of ranges, or list of values)

9. GECA EO GML suggestions
Most important for GECA is limit number of false positive collocations:
Potentially define temporal extent and state per footprint
“ Nadir states” “ Limb states”

10. GECA project status
The project is currently in the Preliminary Design Review (PDR) phase; - User Requirements Review was held in April 2008, - Contract Change was agreed in July 2009, - System Requirements Review was closed in July 2009.
Initial system is due to be operational in early 2010, mainly for testing, and will allow validation analysis of selected data sets from ERS and ENVISAT.
By the end of 2010 the system will be fully operational for all missions and accessible for external users.