ROAMAN is a computer program for autonomous navigation of a mobile robot on a long (as much as hundreds of meters) traversal of terrain. Developed for use aboard a robotic vehicle (rover) exploring the surface of a remote planet, ROAMAN could also be adapted to similar use on terrestrial mobile robots....

Tumbleweed rovers, now undergoing development, are lightweight, inflatable, approximately spherical exploratory robotic vehicles designed to roll across terrain, using only wind for propulsion. Tumbleweed rovers share many features with "beach-ball" rovers, which were discussed in several prior NASA Tech Briefs articles....

GOAS [Global Positioning System (GPS) Occultation Analysis System] is a computer program that accepts signaloccultation data from GPS receivers aboard low-Earth-orbiting satellites and processes the data to characterize the terrestrial atmosphere and, in somewhat less comprehensive...

Multipath Simulator Taking into Account Reflection and Diffraction (MUSTARD) is a computer program that simulates effects of multipath propagation on received Global Positioning System (GPS) signals. MUSTARD is a very efficient means of estimating multipath-induced position and phase...

A prototype wireless data-communication and control system automatically modifies the switching of traffic lights to give priority to emergency vehicles. The system, which was reported in several NASA Tech Briefs articles at earlier stages of development, includes a transponder on each...

A report discusses the technical background and design of the Navigator Global Positioning System (GPS) receiver — a radiation-hardened receiver intended for use aboard spacecraft. Navigator is capable of weak signal acquisition and tracking as well as much faster acquisition of...

A document outlines a computational method that can be incorporated into two prior methods used to invert Global Positioning System (GPS) occultation data [signal data acquired by a low-Earth-orbiting satellite as either this or the GPS satellite rises above or falls below the horizon] to...

A Ka-band integrated range and bearing- angle formation sensor called the Autonomous Formation Flying (AFF) Sensor has been developed to enable deep-space formation flying of multiple spacecraft. The AFF Sensor concept is similar to that of the Global Positioning System (GPS), but the AFF Sensor would...

Motion Measurement Processor (MMP) is one of three computer programs that are used together in the operation of a terrainmapping dual-frequency interferometric synthetic-aperture-radar (SAR) system. The other two programs — Jurassicprok and Calibration Processor — are described in the two...

A key enabling technology that leads to greater spacecraft autonomy is the capability to autonomously and optimally slew the spacecraft from and to different attitudes while operating under a number of celestial and dynamic constraints. The task of finding an attitude trajectory that...

A report describes the time-transfer system of the Gravity Recovery and Climate Experiment (GRACE), in which information on the distribution of Earth mass is extracted from position and time measurements for two spacecraft about 200 km apart in a circular, nearly polar orbit. Each spacecraft...

Lightweight, flexible, thin, one-piece, solar-power packs are undergoing development. Each power pack of this type is a complete, modular, integrated power-supply system comprising three power subsystems that, in conventional practice, have been constructed as separate units and connected...

Four updated video guidance sensor (VGS) systems have been proposed. As described in a previous NASA Tech Briefs article, a VGS system is an optoelectronic system that provides guidance for automated docking of two vehicles. The VGS provides relative position and attitude (6-DOF)...

Circuit boards that contain radio-frequency (RF) and digital circuitry have been developed by NASA to satisfy a requirement of the Port of Houston Authority for relatively inexpensive Global Positioning System (GPS) receivers that indicate the azimuthal headings as well as the positions of ships. The...

A software system processes navigational and sensory information in real time to generate a three- dimensional- appearing image of the external environment for viewing by crewmembers of a windowless aerospacecraft. The design of the particular aerospacecraft (the X-38) is such that the...

A special-purpose software Global Positioning System (GPS) receiver designed for remote sensing with reflected GPS signals is described in "Delay/Doppler-Mapping GPS-Reflection Remote-Sensing System" (NPO-30385), which appears on the previous page. The input accepted by this program comprises...

A system based on ultrasonic sensors has been developed as a means of tracking moving objects with centimeter accuracy. The system is intended especially for tracking pertinent parts of the body of a human subject engaged in control of a remote anthropomorphic robot or immersed in a...