Papers by Russell Carpenter
Goddard Space Flight Center is currently developing advanced spacecraft systems to provide autono... more Goddard Space Flight Center is currently developing advanced spacecraft systems to provide autonomous navigation and control of formation flyers. This paper discusses autonomous relative navigation performance for formations in eccentric, medium and high altitude Earth-orbits using Global Positioning System (GPS) Standard Positioning Service (SPS) and intersatellite range measurements. The performance of several candidate relative navigation approaches is evaluated. These analyses indicate that the relative navigation accuracy is primarily a function of the frequency of acquisition and tracking of the GPS signals. A relative navigation position accuracy of 0.5 meters root-mean-square (RMS) can be achieved for formations in medium-attitude eccentric orbits that can continuously track at least one GPS signal. A relative navigation position accuracy of better than 75 meters RMS can be achieved for formations in high-altitude eccentric orbits that have sparse tracking of the GPS signals. The addition of round-trip intersatellite range measurements can significantly improve relative navigation accuracy for formations with sparse tracking of the GPS signals.
Journal of Guidance, Control, and Dynamics, 2014
ABSTRACT This paper shows how satellite owners/operators may use sequential estimates of collisio... more ABSTRACT This paper shows how satellite owners/operators may use sequential estimates of collision probability, along with a prior assessment of the base risk of collision, in a compound hypothesis ratio test to inform decisions concerning collision risk mitigation maneuvers. The compound hypothesis test reduces to a simple probability ratio test, which appears to be a novel result. The test satisfies tolerances related to targeted false alarm and missed detection rates. This result is independent of the method one uses to compute the probability density that one integrates to compute collision probability. A well-established test case from the literature shows that this test yields acceptable results within the constraints of a typical operational conjunction assessment decision timeline. Another example illustrates the use of the test in a practical conjunction assessment scenario based on operations of the International Space Station.
The Journal of the Astronautical Sciences, 2012
ABSTRACT This paper extends in two directions the results of prior work on generalized linear cov... more ABSTRACT This paper extends in two directions the results of prior work on generalized linear covariance analysis of both batch least-squares and sequential estimators. The first is an improved treatment of process noise in the batch, or epoch state, estimator with an epoch time that may be later than some or all of the measurements in the batch. The second is to account for process noise in specifying the gains in the epoch state estimator. We establish the conditions under which the latter estimator is equivalent to the Kalman filter.
The Journal of the Astronautical Sciences, 2012
When facing a conjunction between space objects, decision makers must chose whether to maneuver f... more When facing a conjunction between space objects, decision makers must chose whether to maneuver for collision avoidance or not. We apply a well-known decision procedure, the sequential probability ratio test, to this problem. We propose two approaches to the problem solution, one based on a frequentist method, and the other on a Bayesian method. The frequentist method does not require any prior knowledge concerning the conjunction, while the Bayesian method assumes knowledge of prior probability densities. Our results show that both methods achieve desired missed detection rates, but the frequentist method's false alarm performance is inferior to the Bayesian method's.
can be achieved for high-Earth orbiting satellites using a GPS receiver with a very stable oscill... more can be achieved for high-Earth orbiting satellites using a GPS receiver with a very stable oscillator. This accuracy improves to better than 15 meters RMS if the GPS receiver's signal acquisition threshold can be reduced by 5 dB-Hertz to track weaker signals.
Das GPS-Experiment auf dem hochfliegenden Satelliten AMSAT-OSCAR 40 (AO-40) wurde erstmals zwisch... more Das GPS-Experiment auf dem hochfliegenden Satelliten AMSAT-OSCAR 40 (AO-40) wurde erstmals zwischen dem 25. September und dem 2. November 2001 für einen Zeitraum von ca. 6 Wochen aktiviert. Die ersten Ergebnisse zeigen, welche weitreichenden Auswirkungen dem Einsatz von GPS als kostengünstigem Sensor für die Bahnbestimmung bei zukünftigen hochfliegenden Missionen (High-Earth-Orbit; HEO) zukommen kann.
The GPS flight experiment on the High Earth Orbit (HEO) AMSAT-OSCAR 40 (AO-40) spacecraft was act... more The GPS flight experiment on the High Earth Orbit (HEO) AMSAT-OSCAR 40 (AO-40) spacecraft was activated for a period of approximately six weeks between 25 September and 2 November, 2001, and the initial results have exciting implications for using GPS as a low-cost orbit determination sensor for future HEO missions. AO-40, an amateur radio satellite launched November 16, 2000, is currently in a low inclination, 1000 by 58,800 km altitude orbit. Although the GPS receiver was not initialized in any way, it regularly returned GPS observations from points all around the orbit. Raw signal to noise levels as high as 12 AMUs (Trimble Amplitude Measurement Units) or approximately 48 dB-Hz have been recorded at apogee, when the spacecraft was close to 60,000 km in altitude. On several occas ions when the receiver was below the GPS constellation (below 20,000 km altitude), observations were reported for GPS satellites tracked through side lobe transmissions. Although the receiver has not returned any point solutions, there has been at least one occasion when four satellites were tracked simultaneously, and this short arc of data was used to compute point solutions after the fact. These results are encouraging, especially considering the spacecraft is currently in a spin-stabilized attitude mode that narrows the effective field of view of the receiving antennas and adversely affects GPS tracking. Already AO-40 has demonstrated the feasibility of recording GPS observations in HEO using an unaided receiver. Furthermore, it is providing important information about the characteristics of GPS signals received by a spacecraft in a HEO, which has long been of interest to many in the GPS community. Based on the data returned so far, the tracking performance is expected to improve when the spacecraft is transitioned to a three axis stabilized, nadir pointing attitude in Summer, 2002.
This paper evaluates several navigation approaches for the first phase of the Magnetospheric Mult... more This paper evaluates several navigation approaches for the first phase of the Magnetospheric Multiscale (MMS) mission, which consists of a tetrahedral formation of four satellites in highly eccentric Earth orbits of approximately 1.2 by 12 Earth radii at an inclination of 10º. The inter-satellite separation is approximately 10 kilometers near apogees. Navigation approaches were studied using ground station range and two-way Doppler measurements, Global Positioning System (GPS) pseudorange measurements, crosslink range measurements among the members flying in formation, and various combinations of these measurement types. An absolute position accuracy of 10 kilometers or better can be achieved with most of the approaches studied and a relative position accuracy of 100 meters or better can be achieved at apogee in some cases. Among the various approaches studied, the approaches that use a combination of GPS and crosslink measurements were found to be more reliable in terms of absolute and relative navigation accuracies and operational flexibility.
AIAA/AAS Astrodynamics Specialist Conference and Exhibit, 2002
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to
The Journal of the Astronautical Sciences, 2012
This paper evaluates several navigation approaches for the Magnetospheric Multiscale (MMS) missio... more This paper evaluates several navigation approaches for the Magnetospheric Multiscale (MMS) mission, which consists of a tetrahedral formation of satellites flying in highly eccentric Earth orbits. For this investigation, inter-satellite separations of approximately 10 kilometers near apogee are used for the first two phases of the MMS mission. Navigation approaches were studied using ground station two-way Doppler measurements, Global Positioning System (GPS) pseudorange measurements, and cross-link range measurements between the members of the formation. An absolute position accuracy of 15 kilometers or better can be achieved with most of the approaches studied, and a relative position accuracy of 100 meters or better can be achieved at apogee in several cases.
AIAA Guidance, Navigation, and Control Conference and Exhibit, 2003
저널·프로시딩즈 | 기술보고서 | 해외연구초록 | Reference DB | 공학설계 | 부품규격 | 항공우주특허 | 원문신청 | 논문스크랩 | 연구자DB. 해외개발 | 국내... more 저널·프로시딩즈 | 기술보고서 | 해외연구초록 | Reference DB | 공학설계 | 부품규격 | 항공우주특허 | 원문신청 | 논문스크랩 | 연구자DB. 해외개발 | 국내개발 | 우주기술전략지도 | AIAA연차보고서 | 저널번역 | 일본항공우주 | 국내연구성과 | IP제공정보 | 부품개발현황. ...
AIAA Guidance, Navigation, and Control Conference and Exhibit, 2003
Navigation accuracy guidelines for orbital formation flying. J Russell Carpenter, Kyle Alfriend 2... more Navigation accuracy guidelines for orbital formation flying. J Russell Carpenter, Kyle Alfriend 2003 AIAA Guidance, Navigation, and Control Conference and Exhibit, 2003. Some simple guidelines based on the accuracy in determining ...
AIAA Guidance, Navigation, and Control Conference and Exhibit, 2004
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Papers by Russell Carpenter