The EUMETSAT Polar System GRAS SAF and Data

The EUMETSAT Polar System GRAS SAF and Data Products Martin B. Sorensen GRAS SAF Project Atmosphere Space Research Division Danish Meteorological Institute (DMI) Copenhagen Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 1

Outline of presentation • • Introduction EUMETSAT Polar System The EUMETSAT Satellite Application Facilities (the SAF concept) GRAS Measurement System The GRAS SAF Operational Centre GRAS SAF products GRAS SAF product dissemination and archives Summary Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 2

Introduction • EUMETSAT Polar System (EPS) is the European component of the joint European/US polar satellite system (IJPS) • EPS mission consists of three Metop satellites with a payload of eight meteorological instruments • • • The first Metop satellite is launched in second half of 2006 The total duration of the EPS mission is 14 years GRAS receiver has been developed especially for radio occultation measurements within the EPS framework by ESA and EUMETSAT => NRT products for NWP applications and continuity of radio occultation data for climate monitoring Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 3

Initial Joint Polar System METOP 1 & 2 a. m. NOAA N & N’ p. m. Global data dump Blind orbits data dump Global data dump SAF SAF NOAA global data METOP blind orbits EPS GS NOAA GS SAF METOP global data NOAA blind orbits NOAA POES SYSTEM Second GPS/RO Users Workshop, August 22 - 24, 2005. SAF EUMETSAT POLAR SYSTEM Slide 4

GRAS receiver • • • Second GPS/RO Users Workshop, August 22 - 24, 2005. 12 bi-frequency channels Codeless-mode capability Oven stabilised USO (Allan deviation 10 -12) Directional high gain occultation antennas for minimising local multipath Onboard DSP => autonomous operations Slide 5

The EUMETSAT Satellite Application Facilities The SAF concept Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 6

Distributed Ground Segment MSG Data Acquisition and Control EPS/Metop Data Processing EUMETSAT HQ Applications Ground Segment Meteorological Products Extraction Facility (MPEF) EUMETSAT HQ Centralised processing and generation of products Unified Meteorological Archive & Retrieval Facility (U-MARF) EUMETSAT HQ GRAS SAF Satellite Application Facilities (SAFs) Decentralised processing and generation of products USERS Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 7

GRAS SAF Overview and Plans • • • GRAS Satellite Application Facility (SAF) started in 1999 – Operational facility for atmosphere products from GRAS instrument on Metop (Launch planned 2006) – 7 year developments Partner Institutes – Danish Meteorological Institute (Host institute) – K. B. Lauritsen, M. B. Sørensen, F. Rubek – Met Office, UK – D. Offiler, Axel v. Engeln, C. Marquardt, (S. Healy) – Institut d’Estudis Espacials de Catalunya (IEEC), Spain – A. Rius, S. Oliveras Milestones – 2004 System test and verification – 2005 Integration test – 2006 Commissioning of Metop – 2007 Operational products from GRAS SAF Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 8

The GRAS measurement system Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 9

NRT Challenge • • • EPS GRAS is the first RO mission that has been from the beginning designed for operational applications NRT requirements for GRAS product dissemination are 2 h 15 min for level 1 b and 3 h for level 2 from the observation Analysis of the NRT feasibility has revealed two main risks: – Timely availability of the auxiliary data – NRT Precise Orbit Determination of the LEO satellite Mitigation of these risks is incorporated in the GRAS Measurement System design There has been no reason to compromise the occultation data processing due to the NRT requirements Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 10

GRAS Measurement System Second GPS/RO Users Workshop, August 22 - 24, 2005. • GRAS Ground Support Network (GSN) provides GPS POD products and ground based measurements • Level 1 b products are processed and disseminated by the EPS Core Ground Segment (CGS) • Level 2 products are processed and disseminated by the GRAS Meteorology SAF • Archived products include raw data, level 1 b, level 2 and all GSN products • Off-line user access to archived products via EUMETSAT UMARF Slide 11

GRAS Ground Support Network (GSN) • GRAS GSN is a service to provide GPS state vectors, clock offset estimates, and clock differencing data for GRAS data processing • • GSN will contain a network of 25 fiducial stations • The GSN Service is designed to support the GRAS NRT data processing requirements GSN coverage for the GPS constellation is > 200 % to ensure service availability via redundancy Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 12

GPS Satellite Visibility Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 13

The GRAS SAF operational processing centre Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 14

GRAS SAF Operationel System Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 15

EUMETCast coverage Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 16

The GRAS SAF Products Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 17

Data and software products from the GRAS SAF DMI processing center Met Office • Data products (Level 2) in NRT (3 hrs) – Refractivity, Temperature, Pressure and Humidity profiles – Surface pressure • Data products Offline – Reprocessed level 2 products – Bending angle (Level 1) • ROP Package – 3/4 DVAR Assimilation Software – Pre-processing tools – Forward operators – Error covariance matrix Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 18

The GRAS data distribution & archives Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 19

NRT Dissemination via RMDCN EUMETCast ? Regional Meteorological Data Communication Network for ECMWF and WMO Region VI Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 20

Off-line and reprocessed data via UMARF - or from the local GRAS SAF archive Unified Meteorological Archive and Retrieval Facility Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 21

UMARF V 2 – Product Details Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 22

Summary • The objective of the EPS GRAS mission is to provide NWP users operationally radio occultation data products • The EPS mission starts in 2006 and provides data continuously at least for 14 years • GRAS data processing and dissemination are performed by the EPS CGS (level 1 b ) and by the GRAS Meteorology SAF (level 2 ) • All archived GRAS products (level 0, level 1 b, and level 2) shall be made available via the EUMETSAT UMARF facility • Analysis and study results indicate that the NRT data processing with the required accuracy is feasible for about 92 % of the observations www. eumetsat. int & http: //grassaf. dmi. dk Second GPS/RO Users Workshop, August 22 - 24, 2005. Slide 23