Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits
During its science phase from 2002–2017, the low-low satellite-to-satellite tracking mission Gravity Field Recovery And Climate Experiment (GRACE) provided an insight into Earth’s time-variable gravity (TVG). The unprecedented quality of gravity field solutions from GRACE sensor data improved the un...
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ftdatacite:10.15488/11213 2023-05-15T16:41:40+02:00 Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits Koch, Igor Duwe, Mathias Flury, Jakob Shabanloui, Akbar 2021 https://dx.doi.org/10.15488/11213 https://www.repo.uni-hannover.de/handle/123456789/11299 en eng Basel : MDPI Creative Commons Attribution 4.0 International CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY GRACE follow-on gravity field recovery time-variable gravity satellite gravimetry dynamic orbit determination satellite-to-satellite tracking KBRR post-fit residuals Dewey Decimal Classification600 | Technik620 | Ingenieurwissenschaften und Maschinenbau Other CreativeWork article 2021 ftdatacite https://doi.org/10.15488/11213 2021-11-05T12:55:41Z During its science phase from 2002–2017, the low-low satellite-to-satellite tracking mission Gravity Field Recovery And Climate Experiment (GRACE) provided an insight into Earth’s time-variable gravity (TVG). The unprecedented quality of gravity field solutions from GRACE sensor data improved the understanding of mass changes in Earth’s system considerably. Monthly gravity field solutions as the main products of the GRACE mission, published by several analysis centers (ACs) from Europe, USA and China, became indispensable products for quantifying terrestrial water storage, ice sheet mass balance and sea level change. The successor mission GRACE Follow-On (GRACE-FO) was launched in May 2018 and proceeds observing Earth’s TVG. The Institute of Geodesy (IfE) at Leibniz University Hannover (LUH) is one of the most recent ACs. The purpose of this article is to give a detailed insight into the gravity field recovery processing strategy applied at LUH; to compare the obtained gravity field results to the gravity field solutions of other established ACs; and to compare the GRACE-FO performance to that of the preceding GRACE mission in terms of post-fit residuals. We use the in-house-developed MATLAB-based GRACE-SIGMA software to compute unconstrained solutions based on the generalized orbit determination of 3 h arcs. K-band range-rates (KBRR) and kinematic orbits are used as (pseudo)-observations. A comparison of the obtained solutions to the results of the GRACE-FO Science Data System (SDS) and Combination Service for Time-variable Gravity Fields (COST-G) ACs, reveals a competitive quality of our solutions. While the spectral and spatial noise levels slightly differ, the signal content of the solutions is similar among all ACs. The carried out comparison of GRACE and GRACE-FO KBRR post-fit residuals highlights an improvement of the GRACE-FO K-band ranging system performance. The overall amplitude of GRACE-FO post-fit residuals is about three times smaller, compared to GRACE. GRACE-FO post-fit residuals show less systematics, compared to GRACE. Nevertheless, the power spectral density of GRACE-FO and GRACE post-fit residuals is dominated by similar spikes located at multiples of the orbital and daily frequencies. To our knowledge, the detailed origin of these spikes and their influence on the gravity field recovery quality were not addressed in any study so far and therefore deserve further attention in the future. Presented results are based on 29 monthly gravity field solutions from June 2018 until December 2020. The regularly updated LUH-GRACE-FO-2020 time series of monthly gravity field solutions can be found on the website of the International Centre for Global Earth Models (ICGEM) and in LUH’s research data repository. These operationally published products complement the time series of the already established ACs and allow for a continuous and independent assessment of mass changes in Earth’s system. Article in Journal/Newspaper Ice Sheet DataCite Metadata Store (German National Library of Science and Technology) Dewey ENVELOPE(-64.320,-64.320,-65.907,-65.907) |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
GRACE follow-on gravity field recovery time-variable gravity satellite gravimetry dynamic orbit determination satellite-to-satellite tracking KBRR post-fit residuals Dewey Decimal Classification600 | Technik620 | Ingenieurwissenschaften und Maschinenbau |
spellingShingle |
GRACE follow-on gravity field recovery time-variable gravity satellite gravimetry dynamic orbit determination satellite-to-satellite tracking KBRR post-fit residuals Dewey Decimal Classification600 | Technik620 | Ingenieurwissenschaften und Maschinenbau Koch, Igor Duwe, Mathias Flury, Jakob Shabanloui, Akbar Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits |
topic_facet |
GRACE follow-on gravity field recovery time-variable gravity satellite gravimetry dynamic orbit determination satellite-to-satellite tracking KBRR post-fit residuals Dewey Decimal Classification600 | Technik620 | Ingenieurwissenschaften und Maschinenbau |
description |
During its science phase from 2002–2017, the low-low satellite-to-satellite tracking mission Gravity Field Recovery And Climate Experiment (GRACE) provided an insight into Earth’s time-variable gravity (TVG). The unprecedented quality of gravity field solutions from GRACE sensor data improved the understanding of mass changes in Earth’s system considerably. Monthly gravity field solutions as the main products of the GRACE mission, published by several analysis centers (ACs) from Europe, USA and China, became indispensable products for quantifying terrestrial water storage, ice sheet mass balance and sea level change. The successor mission GRACE Follow-On (GRACE-FO) was launched in May 2018 and proceeds observing Earth’s TVG. The Institute of Geodesy (IfE) at Leibniz University Hannover (LUH) is one of the most recent ACs. The purpose of this article is to give a detailed insight into the gravity field recovery processing strategy applied at LUH; to compare the obtained gravity field results to the gravity field solutions of other established ACs; and to compare the GRACE-FO performance to that of the preceding GRACE mission in terms of post-fit residuals. We use the in-house-developed MATLAB-based GRACE-SIGMA software to compute unconstrained solutions based on the generalized orbit determination of 3 h arcs. K-band range-rates (KBRR) and kinematic orbits are used as (pseudo)-observations. A comparison of the obtained solutions to the results of the GRACE-FO Science Data System (SDS) and Combination Service for Time-variable Gravity Fields (COST-G) ACs, reveals a competitive quality of our solutions. While the spectral and spatial noise levels slightly differ, the signal content of the solutions is similar among all ACs. The carried out comparison of GRACE and GRACE-FO KBRR post-fit residuals highlights an improvement of the GRACE-FO K-band ranging system performance. The overall amplitude of GRACE-FO post-fit residuals is about three times smaller, compared to GRACE. GRACE-FO post-fit residuals show less systematics, compared to GRACE. Nevertheless, the power spectral density of GRACE-FO and GRACE post-fit residuals is dominated by similar spikes located at multiples of the orbital and daily frequencies. To our knowledge, the detailed origin of these spikes and their influence on the gravity field recovery quality were not addressed in any study so far and therefore deserve further attention in the future. Presented results are based on 29 monthly gravity field solutions from June 2018 until December 2020. The regularly updated LUH-GRACE-FO-2020 time series of monthly gravity field solutions can be found on the website of the International Centre for Global Earth Models (ICGEM) and in LUH’s research data repository. These operationally published products complement the time series of the already established ACs and allow for a continuous and independent assessment of mass changes in Earth’s system. |
format |
Article in Journal/Newspaper |
author |
Koch, Igor Duwe, Mathias Flury, Jakob Shabanloui, Akbar |
author_facet |
Koch, Igor Duwe, Mathias Flury, Jakob Shabanloui, Akbar |
author_sort |
Koch, Igor |
title |
Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits |
title_short |
Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits |
title_full |
Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits |
title_fullStr |
Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits |
title_full_unstemmed |
Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits |
title_sort |
earth’s time-variable gravity from grace follow-on k-band range-rates and pseudo-observed orbits |
publisher |
Basel : MDPI |
publishDate |
2021 |
url |
https://dx.doi.org/10.15488/11213 https://www.repo.uni-hannover.de/handle/123456789/11299 |
long_lat |
ENVELOPE(-64.320,-64.320,-65.907,-65.907) |
geographic |
Dewey |
geographic_facet |
Dewey |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_rights |
Creative Commons Attribution 4.0 International CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.15488/11213 |
_version_ |
1766032133479989248 |