Search Help
Did you find what you were looking for? Yes No
ERS-1/2 Gravity Field Model Product
Entry ID: ERS.ORB.EGM


Summary
Abstract: The gravitational geopotential produces the principal
acceleration on Earth. Therefore a precise orbit
restitution applying dynamic methods requires a precise
model of the geopotential with resolution requirements
depending on the altitude of the satellite. The
gravitational acceleration is the gradient of the
gravitational geopotential. Selected ocean tide parameters
and geocentric coordinates of the satellites tracking
stations are estimated simultaneously.




The gravity field models are available from
by processing ERS-1 data up to 1994. The product is no
longer produced operationally, but copies are available.


Input:


- non-ERS Earth gravity model (satellite-only,
including data from about 30 satellites)
- ERS-1 laser range data of the ERS-1 commissioning
phase
- tracking station survey ties
- a-priori degree variance models


Output: Spherical harmonic coefficients of the
expansion of the geopotential in spherical harmonics, ocean
tide parameters and geocentric coordinates of the satellite
tracking stations.




Product characteristics:

-----------------
Spatial Coverage: global
Spatial Resolution: spherical harmonic expansion of
the gravitational geopotential complete to degree n=50 and
orderm=50 plus higher degree coefficients within order 0
(zonals) and resonant order 12,28 and 43
---------------


To order data please see
"http://earth.esa.int/helpandmail/help_order.html"

Geographic Coverage
 N: 82.0 S: -82.0  E: 180.0  W: -180.0

Temporal Coverage
Start Date: 1991-07-30


Location Keywords
GEOGRAPHIC REGION > GLOBAL


Science Keywords
OCEANS >COASTAL PROCESSES >TIDAL HEIGHT    [Definition]
OCEANS >MARINE GEOPHYSICS >MARINE GRAVITY FIELD    [Definition]
OCEANS >TIDES >TIDAL HEIGHT    [Definition]
SOLID EARTH >GRAVITY/GRAVITATIONAL FIELD >GRAVITY    [Definition]
SOLID EARTH >GRAVITY/GRAVITATIONAL FIELD >SATELLITE ORBITS/REVOLUTION    [Definition]


ISO Topic Category
GEOSCIENTIFIC INFORMATION
OCEANS


Platform
ERS-1 >European Remote Sensing Satellite-1    [Information]
ERS-2 >European Remote Sensing Satellite-2    [Information]


Instrument
PRARE >Precise Range and Range-Rate Equipment    [Information]


Quality
The quality of a model is described by a vector of
characteristic statistical numbers derived from the
comparison of various quantities and error propagation:


- computation of orbital fits to tracking
observations of various satellites and to crossover
differences
- comparison of computed and observed geostationary
satellite longitude accelerations, of lumped coefficients
(pseudo-observations)
- comparison of model coefficients, mean gravity
anomalies and geoid undulations derived from the gravity
model's coefficients and those of other models
- computation of the rms of estimated standard
deviations derived from rigorous error propagation of the
coefficients' variance-covariance matrix to mean gravity
anomalies, to mean geoid heights and to radial orbit
perturbations.


Keywords
GRAVITY
ORBIT


Data Set Progress
COMPLETE


Originating Center
ESA


Data Center
Earthnet Online, European Space Agency    [Information]
Data Center URL: http://earth.esa.int
Dataset ID: ORB.EGM

Data Center Personnel
Name: EARTH OBSERVATION HELP DESK
Phone: +39 06 94180777
Fax: +39 06 94180292
Email: eohelp at esa.int
Contact Address:
ESA/ESRIN
Via G. Galilei
City: Frascati
Postal Code: 00044
Country: Italy



Distribution
Distribution_Media: CD-ROM, File server


Personnel
EARTH OBSERVATION HELP DESK
Role: DIF AUTHOR
Phone: +39 06 94180777
Fax: +39 06 94180292
Email: eohelp at esa.int
Contact Address:
ESA/ESRIN
Via G. Galilei
City: Frascati
Postal Code: 00044
Country: Italy



Creation and Review Dates
Last DIF Revision Date: 2016-11-18



Link to Web Site