Identification

Title

Atmospheric sounding using GPS radio occultation

Abstract

This paper summarizes the radio occultation (RO) technique for remote sounding of the Earth’s atmosphere using the Global Positioning System (GPS) satellites and GPS receivers on low-Earth orbiting (LEO) satellites. As the LEO satellites rise and set with respect to the GPS satellites, the radio waves from the GPS satellites are refracted by the Earth’s atmosphere. Precise measurements of the bending angle of the radio waves are used to derive vertical profiles of atmospheric refractivity, which is a function of electron density in the ionosphere and temperature and water vapor in the stratosphere and troposphere. Results from the GPS/MET, CHAMP, and SAC-C RO missions are summarized, and examples of soundings are presented. Analysis of the CHAMP and SAC-C data indicates that approximately 45% of CHAMP and SAC-C retrieved radio occultation profiles reach below 1 km altitude, compared to only 35% for GPS/MET. All missions exhibit a negative refractivity bias in the lower troposphere of between 1% and 2% compared to NWP models. When constrained to the tropics, only about 20% of the CHAMP occultation profiles reach 1 km from the surface. Taiwan’s National Space Program Office (NSPO), the University Corporation for Atmospheric Research (UCAR), the Jet Propulsion Laboratory (JPL), the Naval Research Laboratory (NRL), and many partners in the university community are developing COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate), a follow-on project for weather and climate, space weather, and geodetic science. COSMIC plans to launch six satellites in 2005. Each satellite will retrieve 400-500 daily profiles† of key ionospheric and atmospheric properties from the tracked GPS radio signals as they are occulted behind the Earth limb. The radio occultation sounding data from COSMIC will contribute significantly to atmospheric research, weather forecasting, and climate modeling.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7wd4449

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

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keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

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West bounding longitude

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Temporal reference

Temporal extent

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Dataset reference date

date type

publication

effective date

2003-01-01T00:00:00Z

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Conformity

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Constraints related to access and use

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Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact