Long-term evaluation of estimated solar radiation pressure coefficients from Copernicus Sentinel-1, -2, -3 satellites

Author(s):  
Heike Peter ◽  
Javier Berzosa ◽  
Jaime Fernández ◽  
Pierre Féménias

<p>The Copernicus POD (Precise Orbit Determination) Service is responsible for the generation of precise orbital products of the Copernicus Sentinel-1, -2, and -3 missions. In the near future, the processing setup of the Copernicus POD Service will be updated to state-of-the-art background models (geopotential, ocean tides and atmospheric gravity) and the use of single-receiver ambiguity fixing using CODE (Center for Orbit Determination in Europe) products.</p><p>In the current orbit parametrization of the six satellites, a solar radiation pressure coefficient is estimated for each daily arc. To provide long-term stability, in particular for the time series of the altimeter Sentinel-3 satellites, it would be preferable to use a constant solar radiation pressure coefficient in the processing. A reprocessing based on the updated models and set-up will be used to compute daily estimates of the solar radiation pressure coefficient for all satellites. The analysis may reveal satellite model deficiencies and might help to improve the satellite macro-models.</p><p>Mean values of the solar radiation pressure coefficients from the long-term series can be used on future operational processing. At the same time a refinement of the selection of the estimated orbit parameters might also be done if necessary, in particular the empirical accelerations. Impact on the orbit determination results and on the quality of the orbits is presented for all six satellites.</p>

2019 ◽  
Vol 11 (24) ◽  
pp. 3024
Author(s):  
Yang Liu ◽  
Yanxiong Liu ◽  
Ziwen Tian ◽  
Xiaolei Dai ◽  
Yun Qing ◽  
...  

The Global Navigation Satellite System (GNSS) ultra-rapid precise orbits are crucial for global and wide-area real-time high-precision applications. The solar radiation pressure (SRP) model is an important factor in precise orbit determination. The real-time orbit determination is generally less accurate than the post-processed one and may amplify the instability and mismodeling of SRP models. Also, the impact of different SRP models on multi-GNSS real-time predicted orbits demands investigations. We analyzed the impact of the ECOM 1 and ECOM 2 models on multi-GNSS ultra-rapid orbit determination in terms of ambiguity resolution performance, real-time predicted orbit overlap precision, and satellite laser ranging (SLR) validation. The multi-GNSS observed orbital arc and predicted orbital arcs of 1, 3, 6, and 24 h are compared. The simulated real-time experiment shows that for GLONASS and Galileo ultra-rapid orbits, compared to ECOM 1, ECOM 2 increased the ambiguity fixing rate to 89.3% and 83.1%, respectively, and improves the predicted orbit accuracy by 9.2% and 27.7%, respectively. For GPS ultra-rapid orbits, ECOM 2 obtains a similar ambiguity fixing rate as ECOM 1 but slightly better orbit overlap precision. For BDS GEO ultra-rapid orbits, ECOM 2 obtains better overlap precision and SLR residuals, while for BDS IGSO and MEO ultra-rapid orbits, ECOM 1 obtains better orbit overlap precision and SLR residuals.


2021 ◽  
Vol 13 (17) ◽  
pp. 3388
Author(s):  
Longjiang Tang ◽  
Jungang Wang ◽  
Huizhong Zhu ◽  
Maorong Ge ◽  
Aigong Xu ◽  
...  

For Global Positioning System (GPS) precise orbit determination (POD), the solar radiation pressure (SRP) is the dominant nongravitational perturbation force. Among the current SRP models, the ECOM and box-wing models are widely used in the International GNSS Service (IGS) community. However, the performance of different models varies over different GPS satellites. In this study, we investigate the performances of different SRP models, including the box-wing and adjustable box-wing as a priori models, and ECOM1 and ECOM2 as parameterization models, in the GPS POD solution from 2017 to 2019. Moreover, we pay special attention to the handling of the shadow factor in the SRP modeling for eclipsing satellites, which is critical to achieve high-precision POD solutions but has not yet been fully investigated. We demonstrate that, as an a priori SRP model, the adjustable box-wing has better performance than the box-wing model by up to 5 mm in the orbit day boundary discontinuity (DBD) statistics, with the largest improvement observed on the BLOCK IIR satellites using the ECOM1 as a parameterization SRP model. The box-wing model shows an insignificant orbit improvement serving as the a priori SRP model. For the eclipsing satellites, the three-dimensional (3D) root mean square (RMS) values of orbit DBD are improved when the shadow factor is applied only in the D direction (pointing toward to Sun) than that in the three directions (D, Y, and B) in the satellite frame. Different SRP models have comparable performance in terms of the Earth rotation parameter (ERP) agreement with the IERS EOP 14C04 product, whereas the magnitude of the length of day (LoD) annual signal is reduced when the shadow factor is applied in the D direction than in the three directions. This study clarifies how the shadow factor should be applied in the GPS POD solution and demonstrates that the a priori adjustable box-wing model combined with ECOM1 is more suitable for high-precision GPS POD solutions, which is useful for the further GNSS data analysis.


GPS Solutions ◽  
2020 ◽  
Vol 24 (2) ◽  
Author(s):  
Yongqiang Yuan ◽  
Xingxing Li ◽  
Yiting Zhu ◽  
Yun Xiong ◽  
Jiande Huang ◽  
...  

1994 ◽  
Vol 31 (5) ◽  
pp. 830-833 ◽  
Author(s):  
Yvonne Vigue ◽  
Stephen M. Lichten ◽  
Ron J. Muellerschoen ◽  
Geoff Blewitt ◽  
Michael B. Heflin

2020 ◽  
Author(s):  
Xinghan Chen ◽  
Maorong Ge ◽  
Harald Schuh

<p>Currently, with the rapid development of the third generation of BeiDou satellite system (BDS-3), the corresponding solar radiation pressure (SRP) forces should be well and soon modeled in order to enhance the performance of precise orbit determination (POD) and precise clock estimation (PCE) for high-precision applications. In this contribution, the BDS-3 post-processed and ultra-rapid PODs have been realized by fully exploiting data provided by the International GNSS Service (IGS). We firstly test the Center for Orbit Determination in Europe (CODE) SRP model (ECOM1) and ECOM2 models and notice a large disagreement of overlapping orbits at the boundary of two adjacent days within an eclipse period. The reason for this could be that the ECOM2 model is over-parameterized or an extra periodic SRP term should be considered. Furthermore, our numerical analyses confirm that the cosinus terms must be excluded and the fourth- and sixth-order SRP sinus terms are significant in the Sun direction for the SRP model of BDS-3 satellites. Therefore, a new SRP model is developed herein to improve BDS-3 orbits, especially for eclipse season. Using the new SRP model, the large fluctuations of 20 cm can be reduced to below 10 cm for the radial-track component of overlapping orbits over eclipse seasons and SLR residuals are improved by a factor of 2 compared to that of ECOM1 and ECOM2. For the predicted orbits, the improvement due to the new SRP model is also demonstrated and the mean offsets of overlapping orbit differences over the eclipse periods can be reduced from -9.3 cm, -18.9 cm, and 39.9 cm to -5.5 cm, 8.3 cm, and 12.7 cm in the radial, cross, and along directions, respectively.</p>


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Tae-Suk Bae ◽  
Chang-Ki Hong

The modeling of solar radiation pressure is the most important issue in precision GNSS orbit determination and is usually represented by constant and periodic terms in three orthogonal axes. Unfortunately, these parameters are generally correlated with each other due to overparameterization, and furthermore, the correlation does not remain constant throughout a long-term period. A total of 500 weeks of GPS daily solutions were estimated with the empirical CODE orbit model (ECOM) to cover various block types of satellites. The statistics of the postfit residuals were analyzed in this study, which shows the dominant annual variation of the correlations over time. There is no significant difference between eclipsing and noneclipsing satellites, and the frequency of the correlation exactly corresponds to the GPS draconitic year. Based on the residual analysis, the ECOM is the most appropriate for the Block IIR/IIR-M satellites but does not properly account for the behavior of either older Block IIA or newer IIF satellites. In addition, the daily mean residuals show a different pattern for satellite orbital planes. Therefore, the orbit model should be customized for the block types and orbital plane for better representation of multi-GNSS orbits.


2021 ◽  
Author(s):  
Jie Li ◽  
Yongqiang Yuan ◽  
Shi Huang ◽  
Chengbo Liu ◽  
Jiaqing Lou ◽  
...  

<p>With the successful launch of the last Geostationary Earth Orbit (GEO) satellite in June 2020, China has completed the construction of the third generation BeiDou navigation satellites system (BDS-3). BDS-3 global services have been initiated in July 2020 with the constellation of 3 GEO, 3 Inclined Geosynchronous Orbit (IGSO) and 24 Medium Earth Orbit (MEO) satellites. In order to further improve the performance of BDS-3 services, the quality of BDS-3 precise orbit product needs further enhancements.</p><p>       The solar radiation pressure (SRP) is the main non-conservative orbit perturbation for GNSS satellites and is the key to improve BDS-3 precise orbit determination. In this study, we focus on the SRP models for BDS-3 satellites. Firstly, the widely used Extended CODE Orbit Model with five parameters (ECOM-5) is assessed. With one-year observations of 2020 from both iGMAS and MGEX networks, the five parameters of ECOM model (D0, Y0, B0, Bc and Bs) are estimated for each BDS-3 satellite. The D0 estimates show an obvious dependency on the elevation angle of the Sun above the satellite orbital plane (denoted as β). In addition, large variations can be noticed in eclipse seasons, which indicate the dramatic changes of SRP. The Y0 estimates vary from -0.6 nm/s<sup>2</sup> to 0.6 nm/s<sup>2</sup> for MEO, -1.0 to 1.0 nm/s<sup>2</sup> for IGSO and -1.0 to 1.5 nm/s<sup>2</sup> for GEO satellites. The B0 estimates of several satellites exhibit a clear dependency on the β angle. The largest variation of B0 appears at C45 and C46, changing from 1.0 nm/s<sup>2</sup> at 15 deg to 8.3 nm/s<sup>2</sup> at 64 deg, which implies that the solar panels of these two satellites may have an obvious rotation lag. To compensate the deficiencies of BDS-3 SRP modeling, we introduce several additional parameters into ECOM-5 model (e.g. introducing higher harmonic terms). The POD performances can be improved by about 10% and 40% for BDS-3 MEO/IGSO and GEO satellites, respectively.</p><p>       Except for the empirical model, we also study the semi-empirical SRP model such as the a priori box-wing model. Since the geometrical and optical properties from BDS-3 metadata are general and rough, we apply more detailed geometrical and optical coefficients for BDS-3 satellites. The POD performance can be improved by about 10% compared to empirical SRP models. Furthermore, considering Earth radiation pressure will have an impact of about 1.3 cm in radial component for MEO satellites.</p>


2015 ◽  
Vol 89 (8) ◽  
pp. 775-791 ◽  
Author(s):  
D. Arnold ◽  
M. Meindl ◽  
G. Beutler ◽  
R. Dach ◽  
S. Schaer ◽  
...  

2013 ◽  
Vol 791-793 ◽  
pp. 1415-1418
Author(s):  
Xiao Peng Liu ◽  
Wei Wei Wang ◽  
Xiao Ni Chen

Satellite solar radiation pressure torque is one of the major long-term interference after the satellite finishes positioning and starts to working. However, there is no method to verify the calculation of solar radiation pressure torque. This paper is to analyze the in-orbit telemetry data of satellite DFH-3. Based on the results of data fitting and pressure torque calculation, the paper aims to test the accuracy of the calculation methods.


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