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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.
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Satellite tracking simultaneous-lobing monopulse receiving system utilizing polarization diversity in coherent and noncoherent operational modes
Parametric comparison between tracking with solar cell arrays and nontracking systems with respect to space power supplies
Task complexity and information processing in tracking task
Operator performance in single and two-axis compensatory tracking systems
Human performance in cross-coupled compensatory tracking task
The precision of a radial basis function (RBF) neural network based tracking method has been assessed against real targets. Precision was assessed against traditionally measured frame-by-frame measurements from the recorded data set. The results show the potential limit for the technique and reveal intricacies associated with empirical data not necessarily observed in simulations.
The objective of this paper is to provide a survey of neural network trends as applied to the tracking of spacecrafts in deep space at Ka-band under various weather conditions and examine the trade-off between tracing accuracy and communication link performance.
A model for the Precise Acquisition, Tracking and Pointing (ATP) system will be discussed and experimental performance data will be presented.
In this paper, a methodology for self-calibrating a multi-beam laser tracking measurement system with planar constraints is proposed.
The JPL beam-waveguide (BWG) antennas are used for spacecraft tracking and for radio-astronomy observations.
This work establishes the threshold performance of noncausal smoothing filters used for tracking residual carrier signals when performance is limited by both phase process noise and additive receiver noise.
This paper describes an extended-image tracking technique based on the maximum likelihood estimation.
The arduous task of tracking multiple flight software images, across redundant on-board processors, recorders and across time, has been automated and systematized via the use of a unified Flight Software Memory Tracker (FMT) Tool.
Searches for gravitational radiation can be performed in space with two spacecraft tracking each other with coherent laser light. This experimental technique could be implemented with two spacecraft carrying an appropriate optical payload, or with the proposed broad-band, space-based laser interferometer detectors of gravitational waves operated in this non-interferometric mode.
The Near-Earth Asteroid Tracking (NEAT) system operates autonomously at the Maui Space Surveillance Site on the summit of the extinct Haleakala Volcano Crater, Hawaii. The program began in December 1995 and continues with an observing run every month.
We examine the feasibility of measuring Along-Track Interferometric (ATI) vector ocean velocities using the azimuth beamwidth of the SAR antenna to obtain angular diversity, at the expense of spatial resolution. A simple model of the measurement is introduced for point targets and moving ocean surfaces to help interpret the velocity measurements.
We present a review of the spacecraft Doppler tracking technique used in broad band searches for gravitational waves in the millihertz frequency band.
Charge collected by diffusion from ion tracks in a semiconductor substrate may be influenced by the substrate diffusion length, which is related to recombination losses. A theoretical analysis shows that, excluding some extreme cases, charge collection is insensitive to spatial variations in the diffusion length funciton, so it is possible to define an effective diffusion length having the property that collected charge can be approximated by assuming a uniform diffusion length equal to this effective value.