scholarly journals Evaluation of Precise Microwave Ranging Technology for Low Earth Orbit Formation Missions with Beidou Time-Synchronize Receiver

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4883
Author(s):  
Xiaoliang Wang ◽  
Shufan Wu ◽  
Deren Gong ◽  
Qiang Shen ◽  
Dengfeng Wang ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Estimation Error ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Time Interval ◽  
Relative Navigation ◽  
Dual Frequency ◽  
Processing Scheme ◽  
Time Frequency ◽  
Range Rate

In this study, submillimeter level accuracy K-band microwave ranging (MWR) equipment is demonstrated, aiming to verify the detection of the Earth’s gravity field (EGF) and digital elevation models (DEM), through spacecraft formation flying (SFF) in low Earth orbit (LEO).In particular, this paper introduces in detail an integrated BeiDou III B1C/B2a dual frequency receiver we designed and developed, including signal processing scheme, gain allocation, and frequency planning. The receiver matched the 0.1 ns precise synchronize time-frequency benchmark for the MWR system, verified by a static and dynamic test, compared with a time interval counter synchronization solution. Moreover, MWR equipment ranging accuracy is explored in-depth by using different ranging techniques. The test results show that MWR achieved 40 μm and 1.6 μm/s accuracy for ranging and range rate during tests, using synchronous dual one-way ranging (DOWR) microwave phase accumulation frame, and 6 μm/s range rate accuracy obtained through a one-way ranging experiment. The ranging error sources of the whole MWR system in-orbit are analyzed, while the relative orbit dynamic models, for formation scenes, and adaptive Kalman filter algorithms, for SFF relative navigation designs, are introduced. The performance of SFF relative navigation using MWR are tested in a hardware in loop (HIL) simulation system within a high precision six degree of freedom (6-DOF) moving platform. The final estimation error from adaptive relative navigation system using MWR are about 0.42 mm (range/RMS) and 0.87 μm/s (range rate/RMS), which demonstrated the promising accuracy for future applications of EGF and DEM formation missions in space.

scholarly journals A Submillimeter-Level Relative Navigation Technology for Spacecraft Formation Flying in Highly Elliptical Orbit

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6524
Author(s):  
Xiaoliang Wang ◽  
Deren Gong ◽  
Yifei Jiang ◽  
Qiankun Mo ◽  
Zeyu Kang ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Formation Flying ◽  
Dynamic Models ◽  
Elliptical Orbit ◽  
Relative Navigation ◽  
Estimation Errors ◽  
Spacecraft Formation ◽  
Spacecraft Formation Flying ◽  
Orbit Dynamic ◽  
Range Rate

Spacecraft formation flying (SFF) in highly elliptical orbit (HEO) has attracted a great deal of attention in many space exploration applications, while precise guidance, navigation, and control (GNC) technology—especially precise ranging—are the basis of success for such SFF missions. In this paper, we introduce a novel K-band microwave ranging (MWR) equipment for the on-orbit verification of submillimeter-level precise ranging technology in future HEO SFF missions. The ranging technique is a synchronous dual one-way ranging (DOWR) microwave phase accumulation system, which achieved a ranging accuracy of tens of microns in the laboratory environment. The detailed design and development process of the MWR equipment are provided, ranging error sources are analyzed, and relative orbit dynamic models for HEO formation scenes are given with real perturbations considered. Moreover, an adaptive Kalman filter algorithm is introduced for SFF relative navigation design, incorporating process noise uncertainty. The performance of SFF relative navigation while using MWR is tested in a hardware-in-the-loop (HIL) simulation system within a high-precision six degrees of freedom (6-DOF) moving platform. The final range estimation errors from MWR using the adaptive filter were less than 35 μm and 8.5 μm/s for range rate, demonstrating the promising accuracy for future HEO formation mission applications.

Simple surrogate models to determine total accessibility duration of low Earth orbit sunsynchronous satellites

2012 ◽  
Vol 227 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Hossein Bonyan Khamseh ◽  
M Navabi
Keyword(s):  
Systems Engineering ◽  
Surrogate Model ◽  
Elevation Angle ◽  
Surrogate Models ◽  
Professional Staff ◽  
Low Earth Orbit ◽  
Propagation Model ◽  
Mission Design ◽  
Earth Orbit ◽  
Time Interval

Short and infrequent access events are inherent characteristics of low Earth orbit sunsynchronous satellites. Furthermore, for such satellites, distribution pattern of access events varies significantly in time. Thus, determination of the metric of total accessibility duration in a given time interval has been a challenge in the field of low Earth orbit satellite systems engineering. In this article, for zero and conventional non-zero minimum elevation angles, surrogate models were developed to determine total accessibility duration of low Earth orbit satellites, based on orbital altitude of the satellite and latitude of the ground segment. For this purpose, concept of repeatability cycle was employed to achieve total accessibility duration in a time-independent manner. Then, a perturbative propagation model was presented to determine pattern of accessibility events and quantify total accessibility duration metric. In order to account for non-zero minimum elevation angles, two distinct approaches were adopted. In the first approach, four modification factors were introduced to modify the surrogate model for zero elevation angle to account for conventional non-zero minimum elevation angles. In the second approach, a dedicated surrogate model was developed to directly determine total accessibility duration for conventional non-zero minimum elevation angles. Numerous examples are examined to verify fidelity of our two proposed approaches. Due to their simplicity, the surrogate models given in this article eliminate the need for professional staff to determine metric of total accessibility duration. The advantage is that considerable saving in required initial staff cost and schedule can be realized, especially in early mission design phases.

scholarly journals Satellite Laser Ranging for Retrieval of the Local Values of the Love h2 and Shida l2 Numbers for the Australian ILRS Stations

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6851
Author(s):  
Marcin Jagoda ◽  
Miłosława Rutkowska ◽  
Paweł Lejba ◽  
Jacek Katzer ◽  
Romuald Obuchovski ◽  
...  
Keyword(s):  
Terrestrial Reference Frame ◽  
Low Earth Orbit ◽  
Satellite Laser Ranging ◽  
Laser Ranging ◽  
Earth Orbit ◽  
Time Interval ◽  
Formal Error ◽  
Station Coordinates ◽  
The Impact ◽  
Research Stage

This paper deals with the analysis of local Love and Shida numbers (parameters h2 and l2) values of the Australian Yarragadee and Mount Stromlo satellite laser ranging (SLR) stations. The research was conducted based on data from the Medium Earth Orbit (MEO) satellites, LAGEOS-1 and LAGEOS-2, and Low Earth Orbit (LEO) satellites, STELLA and STARLETTE. Data from a 60-month time interval, from 01.01.2014 to 01.01.2019, was used. In the first research stage, the Love and Shida numbers values were determined separately from observations of each satellite; the obtained values of h2, l2 exhibit a high degree of compliance, and the differences do not exceed formal error values. At this stage, we found that it was not possible to determine l2 from the data of STELLA and STARLETTE. In the second research stage, we combined the satellite observations of MEO (LAGEOS-1+LAGEOS-2) and LEO (STELLA+STARLETTE) and redefined the h2, l2 parameters. The final values were adopted, and further analyses were made based on the values obtained from the combined observations. For the Yarragadee station, local h2 = 0.5756 ± 0.0005 and l2 = 0.0751 ± 0.0002 values were obtained from LAGEOS-1 + LAGEOS-2 and h2 = 0.5742 ± 0.0015 were obtained from STELLA+STARLETTE data. For the Mount Stromlo station, we obtained the local h2 = 0.5601 ± 0.0006 and l2 = 0.0637 ± 0.0003 values from LAGEOS-1+LAGEOS-2 and h2 = 0.5618 ± 0.0017 from STELLA + STARLETTE. We found discrepancies between the local parameters determined for the Yarragadee and Mount Stromlo stations and the commonly used values of the h2, l2 parameters averaged for the whole Earth (so-called global nominal parameters). The sequential equalization method was used for the analysis, which allowed to determine the minimum time interval necessary to obtain stable h2, l2 values. It turned out to be about 50 months. Additionally, we investigated the impact of the use of local values of the Love/Shida numbers on the determination of the Yarragadee and Mount Stromlo station coordinates. We proposed to determine the stations (X, Y, Z) coordinates in International Terrestrial Reference Frame 2014 (ITRF2014) in two computational versions: using global nominal h2, l2 values and local h2, l2 values calculated during this research. We found that the use of the local values of the h2, l2 parameters in the process of determining the stations coordinates influences the result.

scholarly journals Impact of Attitude Model, Phase Wind-Up and Phase Center Variation on Precise Orbit and Clock Offset Determination of GRACE-FO and CentiSpace-1

2021 ◽  
Vol 13 (13) ◽  
pp. 2636
Author(s):  
Junjun Yuan ◽  
Shanshi Zhou ◽  
Xiaogong Hu ◽  
Long Yang ◽  
Jianfeng Cao ◽  
...  
Keyword(s):  
Data Quality ◽  
Three Dimensional ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Dual Frequency ◽  
Phase Center ◽  
Phase Center Variation ◽  
The Impact ◽  
Clock Offset ◽  
Attitude Model

Currently, low Earth orbit (LEO) satellites are attracting great attention in the navigation enhancement field because of their stronger navigation signal and faster elevation variation than medium Earth orbit (MEO) satellites. To meet the need for real-time and precise positioning, navigation and timing (PNT) services, the first and most difficult task is correcting errors in the process of precise LEO orbit and clock offset determination as much as possible. Launched in 29 September 2018, the CentiSpace-1 (CS01) satellite is the first experimental satellite of LEO-based navigation enhancement system constellations developed by Beijing Future Navigation Technology Co. Ltd. To analyze the impact of the attitude model, carrier phase wind-up (PWU) and phase center variation (PCV) on precise LEO orbit and clock offset in an LEO-based navigation system that needs extremely high precision, we not only select the CS01 satellite as a testing spacecraft, but also the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO). First, the dual-frequency global positioning system (GPS) data are collected and the data quality is assessed by analyzing the performance of tracking GPS satellites, multipath errors and signal to noise ratio (SNR) variation. The analysis results show that the data quality of GRACE-FO is slightly better than CS01. With residual analysis and overlapping comparison, a further orbit quality improvement is possible when we further correct the errors of the attitude model, PWU and PCV in this paper. The final three-dimensional (3D) root mean square (RMS) of the overlapping orbit for GRACE-FO and CS01 is 2.08 cm and 1.72 cm, respectively. Meanwhile, errors of the attitude model, PWU and PCV can be absorbed partly in the clock offset and these errors can generate one nonnegligible effect, which can reach 0.02~0.05 ns. The experiment results indicate that processing the errors of the attitude model, PWU and PCV carefully can improve the consistency of precise LEO orbit and clock offset and raise the performance of an LEO-based navigation enhancement system.

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