GENERAL
Tracking system RIR774
MORABA operates one Precision Instrumentation Tracking Radar for trajectory measurement of balloons, aircraft, and sounding rockets, as well as orbit determination of Space Shuttle and satellites. By employing graphic devices such as plotters and/or screens, aircraft guidance can be accomplished. Via VHF/UHF-radio pilots can be advised with steering commands to precisely follow a pre-determined flight path. The capability of satellite orbit determination was demonstrated by skin tracking the MIR Space Station and the ROSAT satellite.
SYSTEM DESCRIPTION
RIR-774C Range Instrumentation Radar
The RIR-774C radar, which was delivered turn-keyed to MORABA in 1990, is smaller than the AN/MPS-36, being installed in only three standard containers. Hence, transportation is easier and less costly.
Again a concrete platform is needed for the emplacement of the Antenna Container, as well as calibration equipment. However, for short term operations not requiring ultimate accuracy, the system could also be set up on unprepared level ground if it is suitably compact.
Technical Details
The radars share certain commonalities like:
| Transmitter Frequency |
C-Band, 5400-5900 MHz |
| Pulse Repetition Frequency |
IRIG-Standard |
| Transmitter Pulse Widths |
0.25, 0.5, 1.0 micro-seconds |
| Angle Tracking |
by Monopulse Technique |
| Nth-time Around Tracking |
yields extended range capability without reducing Pulse Repetition Frequency |
For selected tracking of transponders both radars feature Transmitter Pulse Coding capability.
The following lists individual technical details:
|
RIR-774C |
| Transmitter peak power output |
> 650 kW |
| Antenna gain |
> 39 dB |
Antenna beam width
(at 3 dB) |
< 1.4 deg |
| Antenna polarization linear |
linear V |
| Receiver noise figure |
< 2.5 dB |
Tracking accuracy
(at 10 dB S/N,
angles range) |
< +/-0.015 deg
< +/-5 m |
Tracking range
(15 cm sphere at
10 dB S/N) |
< 55 km |
The AN/MPS-36, in addition, is capable of Pulse Doppler Frequency extraction on the received signal which derives Range Rate directly rather than through differentiation of Range data.
DATA PROCESSING
Both radars rely on a fully integrated real time data processing system for operation. Aside from on-line data correction and recording, the software also features extended system calibration routines which are more elaborate than previously available and will allow certain calibrations to be performed on a mission-to-mission basis, thus enhancing overall system accuracy. For example, using the antenna mounted TV-camera with associated long focus lens, a Star Calibration Routine provides the possibility with clear sky conditions to measure and evaluate pedestal inherent error sources, day and night.
SUMMERY
Mobile Rocket Base has employed their radars extensively over the years on various campaigns, both in Germany and abroad, providing trajectory data as required, ranging from balloons through aircraft and sounding rockets to satellites. By participation in a USAF department program managed IRSP (Instrumentation Radar Support Program), parts replenishment, even for otherwise outdated and no longer available components, is guaranteed for the foreseeable future. With proper maintenance, both systems will be capable to fulfil their tasks for the years to come.