---
access_dt: ~
aliases:
  - context: dataset
    lexicon: podaac
    term: GRACE_GSM_L2_GRAV_JPL_RL05_1
    url: http://podaac.jpl.nasa.gov/dataset/GRACE_GSM_L2_GRAV_JPL_RL05_1
  - context: datasetId
    lexicon: podaac
    term: PODAAC-GRGSM-20J15
    url: http://podaac.jpl.nasa.gov/ws/search/dataset?datasetId=PODAAC-GRGSM-20J15
attributes: ~
cite_metadata: ~
cited_by: []
contributors:
  - display_name: 'Data Archive : NASA JPL Physical Oceanography Distributed Active Archive Center '
    href: http://52.38.26.42:8080/contributor/3712.yaml
    id: 3712
    organization:
      country_code: US
      display_name: NASA JPL Physical Oceanography Distributed Active Archive Center
      identifier: physical-oceanography-distributed-active-archive-center
      name: NASA JPL Physical Oceanography Distributed Active Archive Center
      organization_type_identifier: federal
      type: organization
      url: http://podaac.jpl.nasa.gov
    organization_uri: /organization/physical-oceanography-distributed-active-archive-center
    person: {}
    person_id: ~
    person_uri: ~
    role_type_identifier: data_archive
    uri: /contributor/3712
data_qualifier: ~
description: 'FOR EXPERT USE ONLY. This dataset contains estimates of Earths static field geototential derived from the Gravity Recovery and Climate Experiment (GRACE) mission measurements, produced by the Jet Propulsion Laboratory (JPL). The major difference between this dataset, 5.1, and 5.0 is that the Earth reference system has been changed to IERS2010 standards and S1/S2 air tide model. 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.'
description_attribution: http://podaac.jpl.nasa.gov/dataset/GRACE_GSM_L2_GRAV_JPL_RL05_1
display_name: GRACE Static Field Geopotential Coefficients JPL Release 5.1
doi: ~
end_time: ~
files: []
href: http://52.38.26.42:8080/dataset/nasa-podaac-grace_gsm_l2_grav_jpl_rl05_1.yaml
identifier: nasa-podaac-grace_gsm_l2_grav_jpl_rl05_1
instrument_measurements:
  - dataset_identifier: nasa-podaac-grace_gsm_l2_grav_jpl_rl05_1
    display_name: gravity-recovery-and-climate-experiment/grace-instrument/nasa-podaac-grace_gsm_l2_grav_jpl_rl05_1
    instrument_identifier: grace-instrument
    platform_identifier: gravity-recovery-and-climate-experiment
    type: instrument_measurement
lat_max: 88
lat_min: -88
lon_max: 180
lon_min: -180
name: GRACE Static Field Geopotential Coefficients JPL Release 5.1
native_id: GRACE_GSM_L2_GRAV_JPL_RL05_1
parents: []
processing_level: ~
publication_year: ~
references: []
release_dt: 2014-10-14T22:31:15
scale: ~
scope: ~
spatial_extent: ~
spatial_ref_sys: ~
spatial_res: ~
start_time: 2002-04-04T00:00:00
temporal_extent: ~
temporal_resolution: ~
type: dataset
uri: /dataset/nasa-podaac-grace_gsm_l2_grav_jpl_rl05_1
url: http://podaac.jpl.nasa.gov/dataset/GRACE_GSM_L2_GRAV_JPL_RL05_1
variables: ~
version: ~
vertical_extent: ~