Wet Tropospheric Correction Methods for Wide-Swath Altimeters

Miao, Xiangying; Wang, Jing; Yang, Zhonghao; Mao, Peng; Miao, Hongli

doi:10.1109/tgrs.2022.3210997

Cited by 3 publications

(2 citation statements)

References 42 publications

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“…The error sources of InIRA in SSH measurement mainly include ionosphere/troposphere delay errors, sea-state bias (SSB), geophysical errors, interferometric phase error, baseline error and system error [34,[50][51][52][53]. The error sources of InIRA are quite different from those of CA although they have some common error sources, e.g., ionosphere/troposphere delay errors, geophysical errors and SSB.…”

Section: Correction Of Errorsmentioning

confidence: 99%

Preliminary Results of Marine Gravity Recovery by Tiangong-2 Interferometric Imaging Radar Altimeter

Sun,

Zhang,

Dong

et al. 2023

Remote Sensing

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This paper presents for the first time the results of marine gravity recovery using the ocean observation data acquired by Tiangong-2 interferometric imaging radar altimeter (TG2 InIRA) which demonstrate not only the balanced accuracies of the north and east components of deflection of the vertical (DOV) as envisaged, but also the improved spatial resolutions of DOV compared with that by conventional altimeters (CAs). Moreover, much higher measurement efficiency owing to the wide-swath capability and the great potential in accuracy improvement of marine gravity field are also demonstrated. TG2 InIRA adopts the interferometry with short baseline and takes small incidence angles, by which wide-swath sea surface height (SSH) can be measured with high accuracy. Gravity recovery experiments in the Western Pacific area are conducted to demonstrate the performance, advantages and capability of TG2 InIRA. SSH data processing algorithms and DOV calculation have been designed by taking the wide-swath feature into account, based on which, the gravity anomalies are then calculated using the inverse Vening Meinesz formula. The derived gravity anomalies are compared with both the published gravity models and the shipborne gravity measurements. The results show that the accuracy of TG2 InIRA is equivalent to, or even a little better than, that of CAs. The fused gravity result using equal TG2 InIRA data and CAs data performs better than those using TG2 InIRA data alone or CAs data alone. Due to the signal bandwidth of TG2 InIRA is only 40 MHz which is much smaller than that of CAs, much higher accuracy can be hopefully achieved for future missions if larger signal bandwidth is used.

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Section: Correction Of Errorsmentioning

confidence: 99%

Preliminary Results of Marine Gravity Recovery by Tiangong-2 Interferometric Imaging Radar Altimeter

Sun,

Zhang,

Dong

et al. 2023

Remote Sensing

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“…The atmospheric delay, ionospheric delay, and sea state bias that nadir altimeters encounter also exist in wide-swath altimeters. Due to the deviation from the nadir measurement, correction methods for the nadir direction need to be developed or modified with targeted error correction models [20][21][22]. On the other hand, errors such as phase errors and baseline errors are introduced during interferometric processing and need to be adequately corrected [23,24].…”

Section: Introductionmentioning

confidence: 99%

Timeliness of Correcting Baseline Error in Wide-Swath Altimeter Based on Reference Topography Data

et al. 2023

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The baseline error is a primary error source of the wide-swath altimeter, directly related to the cross-track distance, and can lead to serious height errors at the swath’s outer edge. Cross-calibration using discrepancies with reference data can effectively estimate and correct the baseline error. However, building a reference surface that accurately describes the sea surface at the observation time is necessary to use this cross-correction method. The dynamic ocean environments where the sea surface structure changes over time are challenging. This paper proposes a method for constructing reference topography data (RTD) based on multi-source data products to correct the baseline error of the wide-swath altimeter. The effectiveness of the proposed method is evaluated using HYCOM ocean model data to assess the timeliness of the baseline error correction. The results demonstrate that using RTD at the observation time of the wide-swath altimeter can significantly correct the baseline error. The RMSE of the corrected sea surface height (SSH) in different regions is typically between 1~2 cm, except in some regions with strong currents where the RMSE is approximately 3~4 cm. However, the time interval between the RTD and the observation time of the wide-swath altimeter can affect the accuracy of the baseline error correction. The timeliness of this correction is influenced by the variability of SSH in different regions. In regions with relatively slow SSH changes near the equator, the effective time based on HYRTD and MORTD can basically reach more than 7 days. In regions where the SSH changes more rapidly, the correction result may no longer be reliable in only 1~3 days.

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