| タイトル | Spread spectrum techniques for the Space Shuttle |
| 著者（英） | Batson, B. H.; Huth, G. K. |
| 著者所属（英） | Axiomatix|NASA Johnson Space Center |
| 発行日 | 1979-01-01 |
| 言語 | eng |
| 内容記述 | The Space Shuttle will employ spread spectrum techniques for both communication and navigation. During on-orbit phases of flight, two-way S-band and Ku-band communication links between the Shuttle and the ground will be available via the tracking and data relay satellite system (TDRSS). A pseudonoise (PN) code will spread the forward-link data spectrum from 32 kbps to 216 kbps to reduce the signal spectral density impinging on the earth's surface, with the S-band code search and acquisition being performed at C/NO-values of around 5 dB-Hz, and with a code length of 2047 chips at a rate of 11.232 Mchips/sec. C/NO-values in the region of 60 dB-Hz to 63 dB-Hz will characterize PN code acquisition in the Ku-band, whose forward-link PN clock is 3.03 Mchips/sec on a 1023-chip length sequence. Primary operational navigation will be provided by the Global Positioning System (GPS), which, after measuring transit time of the PN spread spectrum signal between a number of GPS satellites and itself, scales it by the velocity of light. GPS will enable position estimation accuracy to 30 feet and velocity estimation accuracy to 0.02 ft/sec. |
| NASA分類 | SPACE COMMUNICATIONS, SPACECRAFT COMMUNICATIONS, COMMAND AND TRACKING |
| レポートNO | 81A21903 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/418070 |
|
