|
The UDOP (UHF Doppler) multistatic radar and multiradar system (MSRS) utilizes Doppler radar for missile tracking and trajectory measurement. A target is illuminated at 450MHz. Five receiving stations, located along the baselines with the lengths from , receive signals from the target's transponder at 900MHz. These five stations yield slant-range rate. To compute the range or position, an initial position is required from some other tracking system. The random error is , but total error includes the systematic error of plus the initial error. UDOP had relatively low cost compared with other high-accuracy systems. In the US, MSRS has found important application in the precision measurement of missile trajectories at the Air Force Eastern Test Range, which extends from the Florida mainland to the Indian Ocean. These MSRSs include the AZUSA, the MISTRAM, and the UDOP. All systems employ a cooperative beacon transponder on the observed target and a ground-based transmitting station with several receiving stations at separate, precisely located sites.〔V S Chernyak. Fundamentals of Multisite Radar Systems: Multistatic Radars and Multiradar Systems. (Translated from Russian). CRC Press: New York, 1998. pp.26–27.〕〔Schneid, Daniel L. THE UDOP HANDBOOK. National Technical Information Service document no. AD0609038, JUL 1964, 214 pp.〕 The UDOP used an AN/DRN-11 transponder installed in the Saturn (rocket family) launch vehicle for Project Gemini missions. The C-band CW interferometric AZUSA, in operation from the 1950s, has one transmitter and nine receivers located along two crossed baselines with the total lengths of about . Intermediate receivers spaced at are used for phase ambiguity resolution. The AZUSA system measures range by phase measurement of sideband frequencies modulating the carrier, coherent range by Doppler count, two direction cosines, and two cosine rates. Errors of less than in range and 20 ppm in direction cosine are obtainable.〔 Missile Trajectory Measurement (MISTRAM) is a CW interferometric system with receiving stations situated along two mutually perpendicular baselines spaced at . This MSRS can measure range, four range differences, range rate and four range difference rates of a target. The range error is less than .〔 ==Principles of operation== There is nothing new in using a CW tracking system to obtain metric data. The system was augmented in 1965 by short baselines of a few meters to a few hundred meters in contrast to the conventional UDOP system with baselines of several kilometers and longer. The UDOP system was used extensively for the Saturn program at the NASA John F. Kennedy Space Center (NASA-KSC).〔Instrumentation Systems Analysis Branch (K-ED2) and Tracking Branch (K-EF4), Saturn early launch phase tracking by CW Doppler, John F. Kennedy Space Center, SP-79, April 13, 1964, NASA doc. no. N65-19700, 52 pp.〕 UDOP is a 2-way, coherent, continuous-wave, tracking system. It is a highly reliable data source providing very accurate velocity measurements. The UDOP system, a descendant of Doppler Velocity and Position (DOVAP) was developed by NASA-KSC. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「UDOP」の詳細全文を読む スポンサード リンク
|