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GRACE/GRACE-FO Documentation

Access general documentation and technical notes for GRACE/GRACE-FO.

Documents archived by NASA’s Physical Oceanography Distributed Active Archive Center (PO.DAAC) provide technical information about the Gravity Recovery and Climate Experiment (GRACE) and its follow-on experiment (GRACE-FO). These include handbooks, processing documents, release notes, fact sheets, and technical notes.

GRACE Documentation

Document TitleRevisionAuthorDateDescription
GRACE Product Specification Document
GRACE 327-720		4.6S. BettadpurMay 29, 2012Provides a detailed description of data products at all levels for the GRACE mission.
Document TitleRevisionAuthorDateDescription
GRACE Level 1B Data Product User Handbook JPL D-22027
GRACE 327-733		1.3K. Case, G. Kruizinga, and S.C. WuMarch 24, 2010Provides a comprehensive description of the content and format of the Level 1B data.
AOD1B Product Description Document
GRACE 327-750		6.1Henryk Dobslaw, Inga Bergmann-Wolf, Robert Dill, Lea Poropat, Frank FlechtnerOctober 19, 2017Describes the atmospheric and ocean de-aliasing product (AOD1B) and the barotropic ocean model output (OCN1B).
Algorithm Theoretical Basis Document for GRACE Level 1B Data Processing
GRACE 327-741		1.2S.C. Wu, G. Kruizinga, W. BertigerMay 9, 2006Describes the algorithms producing the main quantities on the Level 1B data.
Document TitleRevisionAuthorDateDescription
GFZ Level-2 Processing Standards Document for Product Release 06
GRACE 327-743		0.0C. Dahle, et al.Aug. 3, 2018Describes the processing standards, models, and parameters adopted for the Level-2 Product Release 06 generated at GFZ.
CSR Level-2 Processing Standards Document for Product Release 06
GRACE 327-742		5.0S. BettadpurMay 1, 2018Describes the processing standards, models, and parameters adopted for the Level-2 Product Release 06 generated at CSR.
JPL Level-2 Processing Standards Document for Product Release 06
GRACE 327-744		6.0Dah-Ning YuanJune 1, 2018Describes the processing standards, models, and parameters adopted for the Level-2 Product Release 06 generated at JPL.
Level-2 Gravity Field Product User Handbook
GRACE 327-734		4.0S. BettadpurApril 25, 2018Provides a description of the Earth gravity field estimates provided by the Level 2 processing.
Document TitleAuthorDateDescription
An Analysis of Gravity-Field Estimation Based on Inter-satellite Dual One-Way Biased Ranging 
JPL Publication 98-15		J.B. ThomasMay 1999Describes a dual one-way approach for extracting "high-rate" k-band intersateliite biased range measurements.
Optimal combination of quaternions from multiple star cameras
JPL Internal Memorandum		L.J. RomansMay 2003Describes a procedure for optimally combining quaternions measured simultaneously from different aligned star cameras.
Document TitleAuthorDescription 
Release Notes for CSR RL06 GRACE L2 productsS. BettadpurGives additional information on CSR RL06 GRACE L2 products (not contained in CSR RL05 processing standards document). 
Release Notes for GFZ RL06 GRACE L2 productsC. DahleGives additional information on GFZ RL06 GRACE L2 products (not contained in GFZ RL05 processing standards document). 
Release Notes for JPL RL06 GRACE L2 productsChristopher M. McCullough, David N. Wiese, & Dah-Ning YuanGives additional information on JPL RL06 GRACE L2 products (not contained in JPL RL05 processing standards document). 
Document Title AuthorDateDescription
GRACE Technical Note #01: Sequence of Events (SOE) File Updated DailyProvides a record of changes of the state of a specific satellite sensor or satellite event, which may alter the processing parameters used for the L1B processing. This file is updated on a daily basis.
GRACE Technical Note #02: ACC blasesS. BettadpurJune 17, 2009Provides recommendations for a-priori bias & scale parameters for Level 1B ACC data.
GRACE Technical Note #03: Sequence of Events (SOE) format descriptionG. KruizingaOctober 20, 2004Provides a detailed description and format information on how the SOE file is organized.
GRACE Technical Note #04: Usage guidelines for GFZ RL03 and JPL RL02 GRACE gravity fields & atmosphere/ocean background modelsS. Bettadpur, F. Flechtner, R. SchmidtMay 9, 2006Provides detailed guidelines for usage on GFZ RL03 and JPL RL02 GRACE models.
GRACE Technical Note #06: Impact of change in AOD1B on RL04 monthly GSMS. BettadpurFeburary 21, 2008Discusses the impact on GRACE level 2 products of the reprocessing of June 2006 through September 2007 GRACE AOD1B data. It is recommended that the following products be replaced with the re-processed ones: AOD1B, GSM-2, GAC-2, and GAD-2.
GRACE Technical Note #11E:  Monthly estimates of C20 and C30 from 6/7 satellites based on GRACE RL06 modelsM. Cheng and J. RiesJanuary 25, 2023Use these estimates to replace the C20 values (and C30 values starting March 2012) from the GSM files of the GRACE(-FO) RL06.X products only. These estimates are not intended to be used with the GRACE RL05 or earlier products.
GRACE Technical Note #12: Convert Global Mean OBP -> Global Mean Ocean Mass  This calculation uses AOD1B 'GAC' fields, and integrates over the ocean-area only; due to the definition of 'GAC' (see AOD1B handbook for further details), the resulting mean value effectively represents 'mean atmospheric mass over the global ocean' for each time step.
GRACE Technical Note #13a: degree-1 (geocenter) gravity coefficients from CSR RL06.2
 
 This file contains monthly estimates of degree-1 gravity coefficients for the GRACE Release-06.2 data, based on ocean and atmospheric models and GRACE coefficients for degrees 2 and higher. 
GRACE Technical Note #13b: degree-1 (geocenter) gravity coefficients from GFZ RL06.1  This file contains monthly estimates of degree-1 gravity coefficients for the GRACE Release-06.1 data, based on ocean and atmospheric models and GRACE coefficients for degrees 2 and higher. 
GRACE Technical Note #13c: degree-1 (geocenter) gravity coefficients from JPL RL06.1  This file contains monthly estimates of degree-1 gravity coefficients for the GRACE Release-06.1 data, based on ocean and atmospheric models and GRACE coefficients for degrees 2 and higher. 
GRACE Technical Note #14: NASA GSFC SLR C20 and C30 solutionsB.D. Loomis and K.E. Rachlin This file contains SLR-derived C20 and C30 values for replacing GRACE/GRACE-FO GSM  Values prior to MJD 56006 use 5 satellites: LAGEOS-1/2, Stella, Starlette, AJISAI Values beginning on MJD 56006 use 7 atellites: LARES and Larets added C30 values are not provided prior to MJD 56006 Estimated parameters for both 5 and 7-satellite configurations: 5x5+C61,S61
Missing and and Unused Days Table  CSV table of missing days for GRACE and GRACE-FO processing. Includes monthly information on missing days as well as unused days by each of the processing centers.

GRACE-FO Documentation

Document TitleAuthorDescription
GRACE-FO SDS NewsletterF. Landerer, et al.Monthly newsletter provided by the GRACE-FO Science Data System (SDS) describing science relevant events on the GRACE-FO space crafts and statistics on L0, L1 and L2 product generation.
GRACE-GRACE-FO Months RL06.cvsNASA/JPLActual monthly-range of the valid data used to compute the GRACE and GRACE-FO Level-2 and -3 monthly products. 
NASA Approved YAML encoding technical noteNASA/JPLDocument that describes the "YAML Ain't Markup Language" (YAML) encoding as the standard format for NASA GRACE/GRACE-FO mission ASCII data.
Document TitleAuthorDateDescription
AOD1B Product Description Document GRACEH. Dobslaw, et al.October 19, 2017Describes the atmospheric and ocean de-aliasing product (AOD1B) and the barotropic ocean model output (OCN1B).
GRACE-FO Level 1 Data Product User HandbookHui Ying Wen, et al.Sept. 11, 2019Provides a comprehensive description of the content and format of the GRACE-FO SDS Level-1A and 1B data products.
Release Notes for GRACE-FO L1B productsHui Ying WenSept. 23, 2019Gives additional information on GRACE-FO L1B products (not contained in other L1 documents).
GRACE-FO Accelerometer Data ProductsChristopher M. M. May 20, 2019Provides the accelerometer data, which is calibrated to enable more optimal gravity field recovery. 
Document TitleAuthorDateDescription 
GRACE-FO Level-2 Gravity Field Product User HandbookDah-Ning YuanMay 22, 2019The GRACE Follow-On Level-2 Gravity Field Product User Handbook provides a description of the Earth gravity field estimates provided by the Level-2 processing. In particular, the relationship of the abstract concept of the geopotential, its instantaneous and mean values, and the specific set of GRACE Follow-On gravity estimates is described in this document.
CSR GRACE-FO L2 Processing Standards Document RL06​H. Save June 6 2019This document serves as a record of the processing standards, models & parameters adopted for the creation of the Level-2 gravity field data products by the GRACE FollowOn (GRACE-FO) Science Data System component at The University of Texas Center for Space Research (UTCSR). 
GFZ GRACE-FO L2 Processing Standards Document RL06​C. Dahle et al.June 3 2019This document serves as a record of the processing standards, models & parameters adopted for the generation of the Level-2 gravity field data products by the GRACE-FO Science Data System component at the GFZ German Research Centre for Geosciences.
JPL GRACE-FO L2 Processing Standards Document RL06​D.-N. YuanMay 28 2019This document serves as a record of the processing standards, models & parameters adopted for the generation of the Level-2 gravity field data products by the GRACE Follow-On Science Data System component at NASA Jet Propulsion Laboratory of the California Institute of Technology (JPL). 
Release Notes for JPL GRACE-FO L2 RL06.3 products  Information on JPL GRACE-FO Level-2 RL06.3 products
Release Notes for CSR GRACE-FO L2 RL06.3 products  Information on CSR GRACE-FO Level-2 RL06.3 products
Release Notes for GFZ GRACE-FO L2 RL06.3 products  Information on GFZ GRACE-FO Level-2 RL06.3 products
Documentation TitleAuthorDateDescription
GRACE-FO Level-3 Data Product User Handbook Savannah S. Cooley​ and Felix W. LandererJuly 10, 2020This Handbook is designed to guide both experienced and beginner users in understanding and using Level-3 GRACE and GRACE-FO data products.The three main objectives of this document are to, 1) provide an overview of the GRACE-FO mission including the instrument design, science data processing, and calibration and validation procedures, 2) provide a description of the available Level-3 GRACE-FO data products and featured science and applications of Level-3 GRACE and GRACE-FO data, and 3) provide a set of step by step, reproducible use cases intended to serve as a reference for users who are interested in GRACE-FO Level-3 data products.  
Release Notes for JPL GRACE-FO L3 MASCON RL06.3 productsDavid WieseSeptember 10, 2024Information on Release 06.3 of the Level-3 MASCON data sets.
Document TitleAuthorDateDescription
GRACE-FO Technical Note #01: Sequence of Events (SOE) File Updated DailyProvides a record of changes of the state of a specific satellite sensor or satellite event, which may alter the processing parameters used for the L1B processing. This file is updated on a daily basis.
GRACE-FO Technical Note #01a: SPACECRAFT_EVENTS (SCE) FileNASA/JPL This file contains GRACE-FO SPACECRAFT_EVENTS, manually written by Level-1 Science Data System operators at NASA JPL, and updated with each weekly incremental data release. The contents of this file augment the machine-readable Sequence of Events file
GRACE-FO Technical Note #01b: KBR_GPS_StatsNASA/JPL KBR_GPS Status Report
GRACE-FO Technical Note #11E:  Monthly estimates of C20 and C30 from 6/7 satellites based on GRACE RL06 models (TXT, 31.77 KB)M. Cheng and J. RiesJanuary 25, 2023Use these estimates to replace the C20 values (and C30 values starting March 2012) from the GSM files of the GRACE(-FO) RL06.X products only. These estimates are not intended to be used with the GRACE RL05 or earlier products.
GRACE-FO Technical Note #12: Convert Global Mean OBP -> Global Mean Ocean Mass July, 2020This calculation uses AOD1B 'GAC' fields, and integrates over the ocean-area only; due to the definition of 'GAC' (see AOD1B handbook for further details), the resulting mean value effectively represents 'mean atmospheric mass over the global ocean' for each time step.
GRACE-FO Technical Note #13a: degree-1 (geocenter) gravity coefficients from CSR RL06.3  This file contains monthly estimates of degree-1 gravity coefficients for the GRACE/GRACE-FO Release-06.3 data by CSR, based on ocean and atmospheric models and GRACE/GRACE-FO coefficients for degrees 2 and higher. 
GRACE-FO Technical Note #13b: degree-1 (geocenter) gravity coefficients from GFZ RL06.3  This file contains monthly estimates of degree-1 gravity coefficients for the GRACE/GRACE-FO Release-06.3 data by GFZ, based on ocean and atmospheric models and GRACE/GRACE-FO coefficients for degrees 2 and higher. 
GRACE-FO Technical Note #13c: degree-1 (geocenter) gravity coefficients from JPL RL06.3  This file contains monthly estimates of degree-1 gravity coefficients for the GRACE/GRACE-FO Release-06.3 data by JPL, based on ocean and atmospheric models and GRACE/GRACE-FO coefficients for degrees 2 and higher.
GRACE-FO Technical Note #14: NASA GSFC SLR C20 and C30 solutionsB.D. Loomis and K.E. Rachlin This file contains SLR-derived C20 and C30 values for replacing GRACE/GRACE-FO GSM  Values prior to MJD 56006 use 5 satellites: LAGEOS-1/2, Stella, Starlette, AJISAI Values beginning on MJD 56006 use 7 atellites: LARES and Larets added C30 values are not provided prior to MJD 56006 Estimated parameters for both 5 and 7-satellite configurations: 5x5+C61,S61
Missing and and Unused Days Table  CSV table of missing days for GRACE and GRACE-FO processing. Includes monthly information on missing days as well as unused days by each of the processing centers.