PRW-9
PRW-9 , NATO code "Thin Skin A", was a radar height finder of the states of the former Warsaw Pact .
It was used to measure elevation angles and to calculate heights at low, medium and high altitudes over small to medium distances. The height was determined after a target was assigned by a panoramic station, an automated command and control station (AFLS) or "by voice" (by telephone) via a command post.
The PRW-9 with its electrical unit was built on two trailers , the transmitter / receiver cabin and a power supply trailer . External synchronization was possible. The PRW-9 was quick to lay, it could be set up or dismantled within 45 minutes. His viewing device ( RHI-scope ) with its remote control devices could be operated up to 300 m away, expediently as an attachment to a PPI-scope of a panoramic station, often the remote viewing device of the P-15 (NATO code "Flat Face A"). The vertical elevation angles were covered by a mechanical swivel from 0 ° to + 20 °. A horizontal all-round search in synchronous rotation to a panoramic station from 0 ° to 360 ° was possible at a defined elevation angle and was used for the reconnaissance of extremely low-flying air targets.
The measurement error in the height determination was a maximum of ± 100 m, in the lateral angle ± 2 ° and in the distance ± 1000 m. A refraction-dependent correction of the height calculation was carried out by using an equivalent temperature T equiv as a correction variable in the formula for height determination. The size of the equivalent temperature was determined by automatic measurement of temperature and air pressure near the ground at the location of the radar device. An auxiliary factor A is calculated from the equivalent temperature :
with which the uncorrected (trigonometric height) H uncorr could be converted to the corrected height H corr :
with r as the slope distance determined by the time of flight measurement, R as the earth's radius with 6370 km and ε , the elevation angle measured by the radar device.
The PRW-9 had an interference protection system against active and passive interference. Switching between three pulse repetition frequencies and a wide range of manual or automatic retuning ( frequency agility ) of the transmitter made this radar relatively insensitive to active interference.
| Technical data PRW-9 | |
|---|---|
| Frequency range | 5 - 9 GHz |
| Pulse repetition time | 1.6 - 2.5 ms |
| Pulse repetition frequency | 400/800 Hz |
| Transmission time (PW) | 1 and 1.7 µs |
| Reception time | |
| Dead time | |
| Pulse power | 700 kW |
| Average performance | 470 W |
| displayed distance | 200 and 300 km |
| Distance resolution | 1.5 km |
| Opening angle | β: 2 ° ε: 0.4 ° |
| Hit count | |
| Antenna round trip time | |
This height finder was also set up on a KrAZ-214 truck instead of on trailers and was then referred to as the PRW-9A.
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- Original regulation of the NVA, LB 103/6/003 "Tactics and Combat Work of the Radio Technical Troops", VVS-No .: C 73971.
- Radar tutorial