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Low-frequency radio navigation system
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Copyright Year | 1983 |
| Description | A method of continuous wave navigation using four transmitters operating at sufficiently low frequencies to assure essentially pure groundwave operation is described. The transmitters are keyed to transmit constant bursts (1/4 sec) in a time-multiplexed pattern with phase modulation of at least one transmitter for identification of the transmitters and with the ability to identify the absolute phase of the modulated transmitter and the ability to modulate low rate data for transmission. The transmitters are optimally positioned to provide groundwave coverage over a service region of about 50 by 50 km for the frequencies selected in the range of 200 to 500 kHz, but their locations are not critical because of the beneficial effect of overdetermination of position of a receiver made possible by the fourth transmitter. Four frequencies are used, at least two of which are selected to provide optimal resolution. All transmitters are synchronized to an average phase as received by a monitor receiver. |
| File Size | 1175537 |
| Page Count | 13 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19840019645 |
| Archival Resource Key | ark:/13960/t46q6sk4b |
| Language | English |
| Publisher Date | 1983-08-02 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Communications And Navigation Phase Modulation Radio Transmitters Synchronism Navigation Aids Time Division Multiplexing Radio Receivers Continuous Radiation Low Frequencies Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Patent |
