Showing papers on "Map matching published in 1963"
TL;DR: In this article, the authors investigated horizon-based navigational systems in which the requirement for vehicular yaw stabilization is not imposed, and showed that error contributing factors such as the aspherical shape of the earth and the seasonal and latitudinal variation of the atmospheric density profile can be largely eliminated by introducing suitable corrections.
Abstract: The earth's horizon provides an important and conspicuous basis for the development of self-contained systems for earth-satellite navigation. The present paper investigates horizonbased navigational systems in which the requirement for vehicular yaw stabilization is not imposed. This permits the development of a variety of navigational techniques which generally fall within one of the following divisions: star matching, stellar almucantar transits, limb occultations, surface almucantar transits and map matching. By measuring time directly the raw data is immediately available for digital processing. Error contributing factors such as the aspherical shape of the earth and the seasonal and latitudinal variation of the atmospheric density profile can be largely eliminated by introducing suitable corrections. Furthermore, heavy reliance can be placed on the digital computer for star identification and for the introduction of these various correction terms. As a result, these techniques have the virtue of requiring only the simplest of navigational equipment. They yield earth-satellite position fixes with potential accuracies in the range from 1 to 10 miles.
27 citations
TL;DR: The Universal Space Tracker (UST) as mentioned in this paper is an electro-optical map matching device that utilizes two-dimensional correlation data processing techniques to provide pitch, yaw and roll data with respect to the recognized field (either planetary surface, star field, or planetary rim).
Abstract: Pattern recognition and the determination of relative attitude are capabilities of an electro-optical map matching device that utilizes two-dimensional correlation data processing techniques. This device is the basic element of a Universal Space Tracker that provides pitch, yaw and roll data with respect to the recognized field (either planetary surface, star field, or planetary rim) for space vehicle guidance applications. The correlation detector and data quantizer is a digital image camera of special design. A feasibility evaluation model of the map matcher has successfully correlated the constellation Gemini under a Maryland atmosphere. The implementation of optical correlation makes possible a universal tracking system with excellent performance characteristics. An advanced version of the tracker is expected to have a 20-arcsecond accuracy, a 5-degree instantaneous acquisition cone, a 20-degree field of view, a weight of 5 pounds, a ?-cubic foot volume and a power consumption of 3 watts.
1 citations