Automatic Detection System For Multi-channel Time Frequency Analysis And Design

The primary work of this thesis is to design than automatic examining system time frequency, the main content includes: the research and application of the frequency measuring using frequency-margin diplosis and the frequency calibrating using subsidiary carrier wave of multicolour television; the design and realization of intelligent frequency calibrating apparatus; the structure designment of the automatic multiprocessing time frequency checking and examining system; researching on the method of time frequency metric examining and confirming; analysing the indeterminacy level in measuring.In the automatic multiprocessing time frequency checking and examining system, the subsidiary carrier wave signal of multicolour television was applied to calibrate the frequency of the standard signal source for each certain period. The frequency calibrating using subsidiary carrier wave of multicolour television has characteristics such as gaining available signal easily, operating simply etc. We can insure that the time frequency signal they provide is exact and credibility as long as we compare the difference of the frequency and period between the subsidiary carrier wave signal got from multicolour television and the signal source to be calibrated.In the structure design of the system, adopting frequency-margin diplosis method, through method of repetitious diplosising frequency, mixing, filting wave, we magnify the frequency-margin between standard frequency source and the signal frequency to be examined, measure the diplosised frequency-margin using electric counter, increasing the testing precision (1～10000times). The computer connects with the radial signal controlling switch and the electric counter through IEEE-488 interface. The computer controls the radial signal program-controlling switch and the measuring equipment, switch on with the signal to be checked and the standard signal orderly, and compare these signals, and controls the electric counter to collect measuring data at the same time.The system primary controlling program is realized through Testpoint, which is a sight programme software plat. The computer enacts the examining time according to the examining rules, start-up the radial signal program-controlling switch orderly, switch on with each signal to be checked, and collect the data. Then analyse and calculate the data that collected, handle and judge them at the same time. The system can realize functions such as data saving, data report-forms, printing and history-record inquiring etc.Using this system, we can accomplish the checking and measuring work of the common time frequency measuring equipment, the main items include: frequency stability, daily aging rate, daily frequency fluctuate, startup characteristics, frequency recuring, frequency veracity. Using this system, adding a low-temperature testing caisson, we can examine and test the apace warm-up crystal oscillator, the main items include: temperature coefficient, frequency adjusting range, load characteristic, voltage characteristic. Using some equipments of this system, purchase a standard GPS receiver, write a software of controlling and data collection﹠ handling, we can check and measure the GPS receiver. The main items include: timing margin, timing stability, orientation margin.The design and manufacture of the automatic multiprocessing time frequency examining system altered the laggard former examining method, it can examine 16 equipments automatically at one time. With sight programme and abundant interface, all measuring work can be finished automatically, and needn't personnel to guard. The system can increase the measuring precision, lighten the labor intensity of the personnel, increase work efficiency, insure the veracity and credibility of the testing data, and provide a powerful guarantee for conventional weapon test.