An Automated Low-Earth Orbit Determination System with High Accuracy Real-Time Capability
GPS-based tracking is increasingly becoming the tracking system of choice for low-Earth orbiters
Automated↗
SEARCH · Engineering Papers
Results for “accuracy”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Design of High-Accuracy Multiple Flyby Trajectories Using Constrained Optimization
The trajectory optimization technique described in this paper provides several distinct advantages over previous formulations. First, fully numerically integrated trajectory modeling is used. That is, no approximations to the trajectory are made and the inclusion of any level of complicated force models desired is allowed. Second, only trajectory propagation is used so there is no requirement for optimization. This is accomplished by the novel method of splitting the trajectory into independent legs, which are then subjected to constrained optimization. Third, each of the trajectory legs may be specified by any convenient set of parameters particularly useful for that leg. Any of these parameters may then be subject to constraints. Fourth, the nonlinear optimization problem is solved by solving a sequence of linear problems which converges to the optimal nonlinear solution. Fifth, the robustness of this formulation requires little or no user interaction with the optimization once a feasible problem has been posed.
flyby↗
TOPEX/Poseidon Mission: Global Measurements of Sea Level at Unprecedented Accuracy
The TOPEX/Poseidon mission, a joint project between the United States and France is described with particular emphasis on measurement capabilities and performance. This satellite provides measurements of global sea level, using 2 microwave radar altimeters, a microwave radiometer, and 3 precision tracking systems. The satellite and measurement systems will be discussed, and science results given.
TOPEX/Poseidon↗
An Automated Low-Earth Orbit Determination System with High Accuracy Real-Time Capability
The flight data have been combined at JPL with ground GPS data from a global network to routinely produce precise TOPEX/Poseidon orbits.
GPS↗
Correlated Environmental Corrections in TOPEX/POSEIDON, with a Note on Ionospheric Accuracy
Estimates of the effectiveness of an altimetric correction, and interpretation of sea level variability as a response to atmospheric forcing, both depend upon assuming that residual errors in altimetric corrections are uncorrelated among themselves and with residual sea level, or knowing the correlations.
altimeters↗
Accuracy of Topographic Maps Derived from ERS-1 Interferometric Radar
A radar interferometric technique for topographic mapping of surfaces promises a high resolution approach to generation of digital elevation models.
altitude↗
Accuracies of Atmospheric Profiles Obtained from GPS Occultations
Radio occultation studies of the terrestrial atmosphere are possible through use of signals transmitted by satellites of the Global Positioning System (GPS) and received by one or more other satellites in low earth orbit (LEO). The perturbed phase of the occulted signal gives direct information on the refractivity profile in the region of occultation, from which vertical profiles of density, pressure, and temperature can be retrieved. Based on model simulations the capability of GPS to provide atmospheric profiles is assessed.
atmospheric↗
Small Inertial Measurement Units- Sources of Error and Limitations on Accuracy
Inertial measurement units (IMUs) with very low mass and power can be manufactured using micromachined accelerometers and gyroscopes. Six degree of freedom packages which require a few watts of power and have less than a kg of mass are available commercially, greatly expanding the potential applications of IMUs in guidance and navigation. Recent advances in small sensor design and fabrication have pushed the performance limits of these small devices. However, the limitations on the precision of small IMUs are not entirely due to the performance of the individual sensors.
Hoenk, Michael E.↗
TOPEX/POSEIDON Mission Global Measurements of Sea Level at Unprecendented Accuracy
This paper describes the TOPEX/POSEIDON mission, ...with particular emphasis on measurement capabilities and performance.
global↗
TOPEX/POSEIDON Mission - Global Measurements of Sea Level at Unprecedented Accuracy
UNKNOWN
TOPEX/POSEIDON↗
CMOS active pixel sensor specific performance effects on star tracker/imager position accuracy
This paper gives the status of theoretical and experimental efforts at JPL in the development of environmentally robust (radiation hard and radiation tolerant), ultra-low power, high performance CMOS active pixel sensor (APS) imagers for star tracker/imager applications.
CMOS↗
High accuracy ground-based near-Earth-asteroid astrometry using synthetic tracking
UNKNOWN
Monchama, Rachel M.↗
Navigation accuracy at Jupiter and Saturn using optical observations of planetary satellites
Autonomous on-board navigation has the potential to enable new types of missions and decrease reliance on NASA’s Deep Space Network for navigation purposes. Previous results have shown that navigating with only optical images of asteroids is feasible for inner planet cruise. In this study, we show that images of natural satellites can be used to navigate during approach and tour phases around the gas giants. We investigate the Jupiter and Saturn systems here, and specifically assess the performance of optical-only navigation for the Juno, Europa Clipper, and Cassini trajectories. Early approach phases and tours at Jupiter would require radiometric data to navigate, but the performance of optical-only data rivals the as-flown performance for Cassini at Saturn.
Broschart, Stephen B.↗
Precision, accuracy, resolution, and coverage: a few insights from GOSAT and OCO-2
UNKNOWN
Eldering, Annmarie↗