GRAS > Global Navigation Satellite System Receiver for Atmospheric Sounding

 (MI_Instrument) uuid: 8293FAD4B8CA75F2E040AC8C5AB4576F
    citation:  (CI_Citation)
        title:  GRAS Products Guide, 4.1. The GRAS instrument
        date:  (CI_Date)
            date:  2006-11-09
            dateType:  (CI_DateTypeCode) publication
        identifier:  (MD_Identifier)
            code:  gov.noaa.ngdc.fgdccitation:31979
        citedResponsibleParty:  (CI_ResponsibleParty)
            organisationName:  EUMETSAT > European Meteorological Satellite Organisation
            contactInfo:  (CI_Contact)
                phone:  (CI_Telephone)
                    voice:  +49(0)6151-807 7
                    facsimile:  +49(0)6151-807 555
                address:  (CI_Address)
                    deliveryPoint:  EUMETSAT Eumetsat Allee 1
                    city:  Darmstadt
                    administrativeArea:  N/A
                    postalCode:  D-64295
                    country:  Germany
                contactInstructions:  For information, go to: http://www.eumetsat.int/Home/Main/AboutEUMETSAT/Contact_Us/index.htm?l=en
            role:  (CI_RoleCode) originator
    identifier:  (MD_Identifier)
        code:  GRAS > Global Navigation Satellite System Receiver for Atmospheric Sounding
    type:  GPS Receiver
    description:  Instrument Type: GPS Receiver, Operational Mode: , Collection Type: TBD, Other Information: GRAS will not view the Earth system with a vertical scan but will instead look tangentially through the Earth's atmosphere. The instrument will measure the time delay of the refracted GPS radio signals as the ray (signal path) skirts the Earth's atmosphere on its way from the transmitting GPS satellite to MetOp. By precisely computing position and velocity of MetOp and the GPS satellite, the measured time delay can be converted to the bending angle of the ray path, which again can be converted to values of temperature, pressure and water vapor content in the atmosphere. The resulting quantities will be functions of height above sea level (from ground level up to approximately 80 km), an atmospheric profile.