A New Solar Radiation Pressure Model for GPS Satellites

AbstractSolar radiation pressure (SRP) is the dominant non-gravitational perturbation for GPS satellites. In the IGS (International GNSS Service), this perturbation is modeled differently by individual analysis centers (ACs). The two most widely used methods are the Empirical CODE orbit Model (ECOM, ECOM2) and the JPL GSPM model. When using ECOM models, a box-wing model or other a priori models, as well as stochastic pulses at noon or midnight, are optionally adopted by some ACs to compensate for the deficiencies of the ECOM or ECOM2 model. However, both box-wing and GSPM parameters were published many years ago. There could be an aging effect going with time. Also, optical properties and GSPM parameters of GPS Block IIF satellites are currently not yet published. In this contribution, we first determine Block-specific optical parameters of GPS satellites using GPS code and phase measurements of 6 years. Various physical effects, such as yaw bias, radiator emission in the satellite body-fixed − X and Y directions and the thermal radiation of solar panels, are considered as additional constant parameters in the optical parameter adjustment. With all the adjusted parameters, we form an enhanced box-wing model adding all the modeled physical effects. In addition, we determine Block-specific GSPM parameters by using the same GPS measurements. The enhanced box-wing model and the GSPM model are then taken as a priori model and are jointly used with ECOM and ECOM2 model, respectively. We find that the enhanced box-wing model performs similarly to the GSPM model outside eclipse seasons. RMSs of all the ECOM and ECOM2 parameters are reduced by 30% compared to results without the a priori model. Orbit misclosures and orbit predictions are improved by combining the enhanced box-wing model with ECOM and ECOM2 models. In particular, the improvement in orbit misclosures for the eclipsing Block IIR and IIF satellites, as well as the non-eclipsing IIA satellites, is about 25%, 10% and 10%, respectively, for the ECOM model. Therefore, the enhanced box-wing model is recommended as an a priori model in GPS satellite orbit determination.

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Adjustable box-wing model for solar radiation pressure impacting GPS satellites

Advances in Space Research ◽

10.1016/j.asr.2012.01.016 ◽

2012 ◽

Vol 49 (7) ◽

pp. 1113-1128 ◽

Cited By ~ 70

Author(s):

C.J. Rodriguez-Solano ◽

U. Hugentobler ◽

P. Steigenberger

Keyword(s):

Solar Radiation ◽

Radiation Pressure ◽

Solar Radiation Pressure ◽

Wing Model ◽

Gps Satellites

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An analysis of a priori and empirical solar radiation pressure models for GPS satellites

Advances in Geosciences ◽

10.5194/adgeo-55-33-2021 ◽

2021 ◽

Vol 55 ◽

pp. 33-45

Author(s):

Xiao Chang ◽

Benjamin Männel ◽

Harald Schuh

Keyword(s):

Solar Radiation ◽

Radiation Pressure ◽

Radial Direction ◽

A Priori ◽

Solar Radiation Pressure ◽

Physical Models ◽

Analytical Models ◽

Block Type ◽

Wing Model ◽

Gps Satellites

Abstract. Among the different non-conservative forces acting on GPS satellites, solar radiation pressure (SRP) has the greatest influence and inappropriate modeling of it can introduce an acceleration with the order of 1 × 10−7 m s−2. There are a variety of empirical, analytical, and hybrid empirical-physical models to describe the SRP effect. Among them, the empirical model developed at the Center for Orbit Determination in Europe (CODE) and analytical models based on a box-wing prototype, namely box-shape bus with solar panels, are widely used in the International GNSS Service (IGS) community. To investigate the effects of different a priori SRP models on top of empirical parameterization, two sets of parameters based on the Empirical CODE Orbit Model (ECOM) and two a priori models including the analytical box-wing model and the empirical GPS Solar Pressure Model (GSPM) are tested for the different GPS satellites. Orbit comparison of different SRP scenarios shows that: (1) the two parameterizations of ECOM perform differently for Block IIA and IIR/IIR-M satellites but lead to fewer differences for Block IIF satellites in terms of orbit difference pattern. The 3D RMS of orbit difference of two parameterizations are 25, 30 and 21 mm for each block type. (2) Adoption of a priori model or change of the ECOM parameterization mainly lead to orbit differences varying with both elevation of the Sun w.r.t. the orbit plane and the satellites' argument of latitude w.r.t. the noon point, which is supposed to be related to the special geometry and attitude of every block type. These differences are especially obvious in radial direction. Analysis of estimated parameters of ECOM indicates that (3) the GSPM.04 performs better than box-wing model to describe the main constant solar radiation. It is found (4) that the asymmetry of estimated ECOM parameters in B direction (i.e., the direction completing the orthogonal system with D direction and satellite's solar panel axes), observed for three Block IIR satellites, causes corresponding asymmetrical orbit differences in radial direction when reduced ECOM parameters are used. This does not apply to the extended ECOM parameterization tested in this study, which indicates the insufficiency of reduced ECOM to parameterize asymmetrical satellites.

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Solar radiation pressure model of GPS and GLONASS satellites considering potential surface radiator impact

10.5194/egusphere-egu2020-8239 ◽

2020 ◽

Author(s):

Bingbing Duan ◽

Urs Hugentobler ◽

Inga Selmke

Keyword(s):

Optical Properties ◽

Solar Radiation ◽

Radiation Pressure ◽

Radiation Effects ◽

A Priori ◽

Solar Radiation Pressure ◽

International Gnss Service ◽

Gps Satellites ◽

Earth Rotation Parameters ◽

Rotation Parameters

<p>Within the IGS (International GNSS Service), precise orbit and clock products of GPS and GLONASS satellites as well as Earth rotation parameters (ERPs) are routinely generated by individual analysis centers. As the dominant non-gravitational perturbation, solar radiation pressure (SRP) is modeled differently by different centers. Without surface properties, the empirical CODE orbit models (ECOM, ECOM2) are mostly used. We find that the ECOM models are not optimal for GLONASS satellites, especially during the eclipsing seasons. Also, the use of a conventional a priori box-wing (BW) model does not help much. By assessing the ECOM estimates we conclude that there are potential radiators on the &#8211;x surface of GLONASS satellites causing orbit perturbations in eclipse as well. Based on this finding, we firstly adjust optical properties of GLONASS satellites considering the potential radiator and thermal radiation effects. Then, we introduce all the adjusted parameters into a new a priori model and jointly use it together with the ECOM models. Results show that orbit misclosure between two consecutive arcs reduces by about 30 % for the ECOM model during the eclipsing seasons. In addition, the spurious pattern of the satellite laser ranging (SLR) residuals is greatly reduced. Also, we have repeated the same adjustment of optical properties for GPS satellites by using 6 years&#8217; data (2014 - 2019). We evaluate GPS orbits, ERPs and geocenter products calculated with different SRP models (ECOM, ECOM+BW, ECOM2, ECOM2+BW, adjustable BW, GSPM) and present corresponding systematic errors of each product at harmonics of the GPS draconitic year.</p>

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