Advantages of RADAR1. Used at night and during periods of reduced visibility when visual means of navigation are limited or impossible.
2. Available at greater ranges from land. 3. Fixes may be obtained from a single object. 4. Fixes obtained quickly & accurately. 5. Can locate & track shipping and storms. Integrated Navigation RADARs
More sophisticated radars are in use today that not only provide bearing and range information, but also perform the following functions:
? Contact Tracking and collision avoidance provided with an Automatic Radar Plotting Aid (ARPA) radar.
? When integrated with an ECDIS, the radar provides an overlay to the electronic chart in use, displaying the location of land, contacts, and navigation information on one display. ? Display Navigation track information on the radar set.
? Displays identification of ships equipped with the Automatic Information System (AIS). Part 3 Satellite Navigation System
3.1 Introduction to the Development of Satellite Navigation
3.1.1 History
History changed on October 4, 1957, when the Soviet Union
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successfully launched Sputnik I (Спутник I). That launch ushered in new political, military, technological, and scientific developments.
? On 4 October 1957, launch of Sputnik I.
? On 3 November 1957, Sputnik II was put into orbit. ? Sputnik III was launched on 18 September 1958. Doppler Shift
Doppler Shift is an effect that is associated with any wave phenomena (such as sound waves).
3.1.2 Plan TRANSIT
Johns Hopkins University signed a contract (Plan TRANSIT) with American Navy in 1960;Navy Navigation Satellite System (NNSS) was built up in January 1964;
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William H. Guier, Frank T. McClure, and George C. Weiffenbach (l to r) discuss the principles of the Transit Navigation System (later called the Navy Navigation Satellite System).
Richard B. Kerschner Award
This award is for the recognition of an individual who has made a substantial contribution to the technology of navigation and positioning equipment, systems, or practices. Initiated in 1986, it is presented at the biennial Position Location and Navigation (PLANS) Conference.Navy Navigation Satellite System—NNSS In 1967, Vice President Hubert Humphrey released the system for public and commercial use by ships of all friendly nations, and in October he presented Dr. Kershner with a Distinguished Public Service Award. At the end of 1996 Transit, the Navy Navigation Satellite System, was retired after more than 32 years of continuous, successful service to the U.S. Navy.
During its 32 years of operation, the Transit Navigation System provided an extremely accurate and reliable global navigation system for the U.S. Navy and the civilian community. The system was continuously improved through the years and contributed to numerous advances in space science, engineering, and technology.
The Transit system spawned a number of space \the two-frequency method for correcting ionospheric error, solar attitude detectors, dual-launch payloads, satellite electronic memory an uplink authentication system, gravity-gradient stabilization. development of satellite compensation for drag and radiation pressure, the use of pulsed plasma micro-thrusters, and hardening of the spacecraft against an enhanced radiation environment.
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Transit Constellation
The Orbit Interval of TRANSIT satellite NNSS Navigation Principle
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t1 t2 D2 D1 t3 D3 Orbit 3.1.3 NAVSTAR GPS
? NAVigation Satellite Timing And Ranging Global
Positioning System ? Developed and maintained by the Department of Defense ? Operates two positioning services
– Precise Positioning Service (PPS) – Standard Positioning Service (SPS)
? Consists of three segments:
– User – handheld receiver – Space – satellite constellation – Control – tracking and corrections
? Generations of the current system
– Block I
? Series of 11 experimental satellites
? 1st satellite launched in 1978, the last in
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