PODAAC-GRGAC-20C06
type: Dataset
description: FOR EXPERT USE ONLY. This dataset contains estimates of Earths geopotential field derived from the Gravity Recovery and Climate Experiment (GRACE) mission measurements and a non-tidal oceanic and atmospheric model produced by the Center for Space Research (CSR) at University of Texas at Austin. The data are in spherical harmonics averaged over approximately a month. The primary objective of the GRACE mission is to obtain accurate estimates of the mean and time-variable components of the Earths gravity field variations. This objective is achieved by making continuous measurements of the change in distance between twin spacecraft, co-orbiting in about 500 km altitude, near circular, polar orbit, spaced approximately 200 km apart, using a microwave ranging system. In addition to these range change, the non-gravitional forces are measured on each satellite using a high accuracy electrostatic, room-temperature accelerometer. The satellite orientation and position (and timing) are precisely measured using twin star cameras and a GPS receiver, respectively. Spatial and temporal variations in the Earths gravity field affect the orbits (or trajectories) of the twin spacecraft differently. These differences are manifested as changes in the distance between the spacecraft, as they orbit the Earth. This change in distance is reflected in the time-of-flight of microwave signals transmitted and received nearly simultaneously between the two spacecraft. The change in this time of fight is continuously measured by tracking the phase of the microwave carrier signals. The so called dual-one-way range change measurements can be reconstructed from these phase measurements. This range change (or its numerically derived derivatives), along with other mission and ancillary data, is subsequently analyzed to extract the parameters of an Earth gravity field model.
issued: 2025-12-02T10:37:31.608894
modified: 2025-12-02T10:37:31.608897
contact point: Organization
  fn: Wen-Hao Li
keyword: amerigeo
keyword: amerigeoss
keyword: ckan
keyword: geo
keyword: geoss
keyword: national
keyword: north-america
keyword: united-states

View this dataset's user's guide
type: Distribution
description: UTCSR Level-2 Processing Standards Document For Level-2 Product Release 06
format: PDF
issued: 2019-02-28T02:45:23.378342
modified: 2025-12-02T10:37:31.601229
access URL: ftp://podaac-ftp.jpl.nasa.gov/allData/grace/docs/L2-CSR006_ProcStd_v5.0.pdf
media type: application/pdf

View this dataset's user's guide
type: Distribution
description: Product Specification Document
format: PDF
issued: 2019-02-28T02:45:23.378332
modified: 2025-12-02T10:37:31.600826
access URL: ftp://podaac-ftp.jpl.nasa.gov/allData/grace/docs/ProdSpecDoc_v4.6.pdf
media type: application/pdf

Download this dataset
type: Distribution
description: The FTP base directory location for the collection.
format: HTML
issued: 2019-02-28T02:45:23.378298
modified: 2025-12-02T10:37:31.599934
access URL: ftp://podaac-ftp.jpl.nasa.gov/allData/grace/L2/CSR/RL06
media type: text/html

View documentation related to this dataset
type: Distribution
description: Release Notes for GRACE L-2 products - version UTCSR RL-06
format: HTML
issued: 2019-02-28T02:45:23.378321
modified: 2025-12-02T10:37:31.600394
access URL: ftp://podaac-ftp.jpl.nasa.gov/allData/grace/docs/ReleaseNotes_csr_RL06.txt
media type: text/html

View documentation related to this dataset
type: Distribution
description: GRACE Mission Page
format: HTML
issued: 2019-02-28T02:45:23.378352
modified: 2025-12-02T10:37:31.601629
access URL: https://podaac.jpl.nasa.gov/GRACE
media type: text/html

Download this dataset
type: Distribution
description: (Search Granule)
format: HTML
issued: 2019-02-28T02:45:23.378369
modified: 2025-12-02T10:37:31.602427
access URL: https://podaac.jpl.nasa.gov/ws/search/granule/
media type: text/html

View this dataset's user's guide
type: Distribution
description: Level-2 Gravity Field Product User Handbook
format: PDF
issued: 2019-02-28T02:45:23.378360
modified: 2025-12-02T10:37:31.602027
access URL: ftp://podaac-ftp.jpl.nasa.gov/allData/grace/docs/L2-UserHandbook_v4.0.pdf
media type: application/pdf

US Migrating
type: Agent