NON-MILITARY NAVIGATION BY SATELLITES
Discussion of the various economic and technical considerations involved in the civilian application of the transit navigation satellite system
SEARCH · Engineering Papers
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.
Discussion of the various economic and technical considerations involved in the civilian application of the transit navigation satellite system
The ship position and attitude measurement system that was installed aboard the tracking ship Vanguard is described. An overview of the entire system is given along with a description of how precise time and frequency is utilized. The instrumentation is broken down into its basic components. Particular emphasis is given to the inertial navigation system. Each navigation system used, a mariner star tracker, navigation satellite system, Loran C and OMEGA in conjunction with the inertial system is described. The accuracy of each system is compared along with their limitations.
Satellite navigation aid for marine craft, objectives of ATS and ATS-A, -B and -C spacecraft
Navigation of Mariner spacecraft to Jupiter and beyond will require greater accuracy of positional determination than heretofore obtained if the full experimental capabilities of this type of spacecraft are to be utilized. Advanced navigational techniques which will be available by 1977 include Very Long Baseline Interferometry (VLBI), three-way Doppler tracking (sometimes called quasi-VLBI), and two-way Doppler tracking. It is shown that VLBI and quasi-VLBI methods depend on the same basic concept, and that they impose nearly the same requirements on the stability of frequency standards at the tracking stations. It is also shown how a realistic modelling of spacecraft navigational errors prevents overspecifying the requirements to frequency stability.
Mariner 9 achieved successful photography of the stars, the purpose of the experiment being to measure camera parameters associated with point source photometry, and to examine the feasibility of using stars as invariant calibration sources and a reference for optical navigation. The Mariner 9 camera-B photography demonstrated photometric response consistency over a limited sample of data to better than 15%. Camera performance verified the ability to model vidicon response characteristics as well as demonstrated an imaging capability sufficient to permit the use of stars for photometric calibration.
Remote sensing and probing of ocean from low altitude positions - marine meteorology
A description is given of the navigation of Mariner 9, which included not only precision flight path control but also pointing of the scientific instruments mounted on a two-degree of freedom scan platform. Flight path control involved the determination of the spacecraft trajectory and the design and execution of the propulsive maneuvers required to effect the necessary changes in the trajectory. Radiometric tracking data provided by the Deep Space Network (DSN) were the principal data type used in the orbit determination process. During the Mars approach phase, optical tracking data were also used, but only on an experimental basis.
Design and analysis of self correcting automatic navigation system for Mariner Mars spacecraft
The phase-coherent range and Doppler tracking data obtained as a basis for the navigation of the Mariner 9 spacecraft from earth to Mars determine also the earth-moon mass ratio. As the earth revolves about the center of mass of the earth-moon system, a sinusoidal curve is impressed on the range and Doppler tracking data with a frequency equal to the sidereal mean motion of the moon. The mass ratio was determined from range and Doppler data obtained over a period of 15 weeks. The results from the Mariner Mars 1971 data are presented in a table together with previous results obtained in connection with other spacecraft.
A general description of the Viking interplanetary orbit determination activity extending from launch to Mars encounter is given. The emphasis is on the technical fundamentals of the problem, basic strategies and data types used, quantitative results, and specific conclusions derived from the inflight experience. Special attention is given to the use of the spacecraft-based optical measurements and their first application as a principal navigational data type for an interplanetary mission. The optical-based orbit determination, in fact, was the primary contributor to the exceptional interplanetary navigation accuracy experienced by both Viking missions. The Viking application of optical orbit determination relied in large part on the technology developed and demonstrated by the Mariner 9 Optical Navigation Demonstration.
Satellite navigation systems for marine and aircraft industry global, all-weather position determination and communications noting range measurement, range rate, NASA techniques, etc
The U.S. Coast Guard has developed a qualification test to screen photovoltaic modules for utilization on marine aids to navigation. The test is based on a combined-environment of hot and cold saltwater immersion and air pressurization. The test has demonstrated a very high acceleration factor and excellent correlation of electrical failures with modules in a concurrent real-time marine exposure.
The extended process of providing station location estimates for use in orbit determination at launch and during the course of the mission, is outlined. Station location sets provided for Mariner Mars 1971 navigation support are given. Data cover set construction, basis for construction, and a comparison of estimated sets with final sets.
The paper presents the results of the prelaunch navigation studies conducted for the Mariner spacecraft launched toward encounters with the giant planets. The navigation system and the strategy for using this system are described. The requirements on the navigation system demanded by the goals of the project are mentioned, and the predicted navigational capability relative to each of the requirements is discussed. Baseline navigation results for three possible trajectories are analyzed.
A laboratory and field test program was conducted to quantify the optical navigation parameters of the Mariner vidicons. A scene simulator and a camera were designed and built for vidicon tests under a wide variety of conditions. Laboratory tests characterized error sources important to the optical navigation process and field tests verified star sensitivity and characterized comet optical guidance parameters. The equipment, tests and data reduction techniques used are described. Key test results are listed. A substantial increase in the understanding of the use of selenium vidicons as detectors for spacecraft optical guidance was achieved, indicating a reduction in residual offset errors by a factor of two to four to the single pixel level.
The marine energy industry is steadily advancing as more devices are deployed worldwide. However, several challenges and barriers remain, such as lingering uncertainty regarding the potential environmental effects of marine energy devices on marine animals, habitats, and ecosystems. Concerns have led to difficulty navigating permitting and consenting processes and receiving authorization to deploy devices in the marine environment, including extended timelines and costs. Based on existing risk registers, a novel marine energy environmental risk register was created to help the marine energy industry move beyond these barriers. This risk register aims to aid marine energy device and project developers identify and assess potential environmental risks early in device design or project planning, document and track potential environmental interactions, prioritize risks and determine risk responses, and make decisions throughout device or project development. It can also be used as a tool to assist in communicating with regulators and advisors during permitting processes and to inform stakeholder and community engagement efforts. This paper details the methods and process to develop a risk register specific to environmental effects of marine energy and describes two use cases (one for wave energy and another for tidal energy) to highlight example results. Due to the tool's novelty, the paper showcases its application for the marine energy industry and acknowledges limitations and possible future improvements. Overall, the environmental risk register shows promise to support marine energy developers when identifying, tracking, and addressing potential environmental risks and to help successfully navigate permitting and deploy marine energy devices responsibly.
The ocean microbe‐metabolite network involves thousands of individual metabolites that encompass a breadth of chemical diversity and biological functions. These microbial metabolites mediate biogeochemical cycles, facilitate ecological relationships, and impact ecosystem health. While analytical advancements have begun to illuminate such roles, a challenge in navigating the deluge of marine metabolomics information is to identify a subset of metabolites that have the greatest ecosystem impact. Here, we present an ecological framework to distill knowledge of fundamental metabolites that underpin marine ecosystems. We borrow terms from macroecology that describe important species, namely “dominant,” “keystone,” and “indicator” species, and apply these designations to metabolites within the ocean microbial metabolome. These selected metabolites may shape marine community structure, function, and health and provide focal points for enhanced study of microbe‐metabolite networks. Applying ecological concepts to marine metabolites provides a path to leverage metabolomics data to better describe and predict marine microbial ecosystems.
The history of the deep space navigation system developed by NASA is outlined. Its application to Mariner, Viking and Pioneer missions is reviewed. Voyager navigation results for Jupiter and Saturn are commented on and velocity correction in relation to fuel expenditure and computer time are discussed. The navigation requirements of the Gahleo and Venus orbiting imaging radar (VOIR) missions are assessed. The measurement and data processing systems are described.