### Abstract

Spaceborne GPS receiver is used for not only a primary tracking system for precision orbit determination on ground but also a core equipment to provide real-time ephemeris for onboard attitude control in many missions. In general, the position and velocity accuracy of GPS navigation solution without dynamic filter has 25 m(1 σ) and 1.0 m/s(1 σ), respectively. However, GPS navigation solution from most of spaceborne GPS receiver has abnormal excursions of about 4 km and 3 m/s from normal error range for space operation. These excursions have a negative effect on the attitude control system. In this research, a spaceborne GPS receiver, which includes real-time orbit determination function using unscented Kaiman filter(UKF), was developed to provide more accurate and robust real-time ephemeris. Dynamical orbit determination is a nonlinear problem where the perturbing factors are not easily modeled. Extended Kaiman filter(EKF) is one of the favorable approaches as the navigation state estimator. However, the divergence due to modeling errors, which EKF highly depends on a predefined dynamic model, is a critical problem. In this research, UKF algorithm, which uses a finite number of sigma points to propagate the probability of state distribution, was implemented for the nonlinear dynamic process modeling. And also, optimal UKF algorithm based on Kaiman minimum variance method was applied fro real-time calculations. 7 ^{th} order Runge-Kutta numerical integration was applied for orbit propagation and perturbations due to geopotential, gravity of the Sun and Moon, solar radiation pressure, and atmospheric drag were modeled. GPS navigation solution, which consists of position and velocity, was used as observation for UKF. The spaceborne GPS receiver hardware design is mainly built with the 12 channel L 1 C/A code baseband correlator and 32-bit floating point DSP microprocessor. The performance test of real-time orbit determination using UKF was implemented using the COSMIC navigation solution data in the DSP-based spaceborne GPS receiver.

Original language | English |
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Title of host publication | 60th International Astronautical Congress 2009, IAC 2009 |

Pages | 2891-2896 |

Number of pages | 6 |

Volume | 4 |

Publication status | Published - 2009 Dec 1 |

Event | 60th International Astronautical Congress 2009, IAC 2009 - Daejeon, Korea, Republic of Duration: 2009 Oct 12 → 2009 Oct 16 |

### Other

Other | 60th International Astronautical Congress 2009, IAC 2009 |
---|---|

Country | Korea, Republic of |

City | Daejeon |

Period | 09/10/12 → 09/10/16 |

### Fingerprint

### All Science Journal Classification (ASJC) codes

- Space and Planetary Science
- Astronomy and Astrophysics

### Cite this

*60th International Astronautical Congress 2009, IAC 2009*(Vol. 4, pp. 2891-2896)

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*60th International Astronautical Congress 2009, IAC 2009.*vol. 4, pp. 2891-2896, 60th International Astronautical Congress 2009, IAC 2009, Daejeon, Korea, Republic of, 09/10/12.

**Development of spaceborne GPS receiver with real-time orbit determination using unscented Kalman filter.** / Choi, Eun Jung; Yoon, Jae Cheol; Lee, Byoung Sun; Park, Sang Young; Choi, Kyu Hong.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

TY - GEN

T1 - Development of spaceborne GPS receiver with real-time orbit determination using unscented Kalman filter

AU - Choi, Eun Jung

AU - Yoon, Jae Cheol

AU - Lee, Byoung Sun

AU - Park, Sang Young

AU - Choi, Kyu Hong

PY - 2009/12/1

Y1 - 2009/12/1

N2 - Spaceborne GPS receiver is used for not only a primary tracking system for precision orbit determination on ground but also a core equipment to provide real-time ephemeris for onboard attitude control in many missions. In general, the position and velocity accuracy of GPS navigation solution without dynamic filter has 25 m(1 σ) and 1.0 m/s(1 σ), respectively. However, GPS navigation solution from most of spaceborne GPS receiver has abnormal excursions of about 4 km and 3 m/s from normal error range for space operation. These excursions have a negative effect on the attitude control system. In this research, a spaceborne GPS receiver, which includes real-time orbit determination function using unscented Kaiman filter(UKF), was developed to provide more accurate and robust real-time ephemeris. Dynamical orbit determination is a nonlinear problem where the perturbing factors are not easily modeled. Extended Kaiman filter(EKF) is one of the favorable approaches as the navigation state estimator. However, the divergence due to modeling errors, which EKF highly depends on a predefined dynamic model, is a critical problem. In this research, UKF algorithm, which uses a finite number of sigma points to propagate the probability of state distribution, was implemented for the nonlinear dynamic process modeling. And also, optimal UKF algorithm based on Kaiman minimum variance method was applied fro real-time calculations. 7 th order Runge-Kutta numerical integration was applied for orbit propagation and perturbations due to geopotential, gravity of the Sun and Moon, solar radiation pressure, and atmospheric drag were modeled. GPS navigation solution, which consists of position and velocity, was used as observation for UKF. The spaceborne GPS receiver hardware design is mainly built with the 12 channel L 1 C/A code baseband correlator and 32-bit floating point DSP microprocessor. The performance test of real-time orbit determination using UKF was implemented using the COSMIC navigation solution data in the DSP-based spaceborne GPS receiver.

AB - Spaceborne GPS receiver is used for not only a primary tracking system for precision orbit determination on ground but also a core equipment to provide real-time ephemeris for onboard attitude control in many missions. In general, the position and velocity accuracy of GPS navigation solution without dynamic filter has 25 m(1 σ) and 1.0 m/s(1 σ), respectively. However, GPS navigation solution from most of spaceborne GPS receiver has abnormal excursions of about 4 km and 3 m/s from normal error range for space operation. These excursions have a negative effect on the attitude control system. In this research, a spaceborne GPS receiver, which includes real-time orbit determination function using unscented Kaiman filter(UKF), was developed to provide more accurate and robust real-time ephemeris. Dynamical orbit determination is a nonlinear problem where the perturbing factors are not easily modeled. Extended Kaiman filter(EKF) is one of the favorable approaches as the navigation state estimator. However, the divergence due to modeling errors, which EKF highly depends on a predefined dynamic model, is a critical problem. In this research, UKF algorithm, which uses a finite number of sigma points to propagate the probability of state distribution, was implemented for the nonlinear dynamic process modeling. And also, optimal UKF algorithm based on Kaiman minimum variance method was applied fro real-time calculations. 7 th order Runge-Kutta numerical integration was applied for orbit propagation and perturbations due to geopotential, gravity of the Sun and Moon, solar radiation pressure, and atmospheric drag were modeled. GPS navigation solution, which consists of position and velocity, was used as observation for UKF. The spaceborne GPS receiver hardware design is mainly built with the 12 channel L 1 C/A code baseband correlator and 32-bit floating point DSP microprocessor. The performance test of real-time orbit determination using UKF was implemented using the COSMIC navigation solution data in the DSP-based spaceborne GPS receiver.

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M3 - Conference contribution

SN - 9781615679089

VL - 4

SP - 2891

EP - 2896

BT - 60th International Astronautical Congress 2009, IAC 2009

ER -