High-speed Synchronous Data Acquisition System Design Of SAMR

Microwave radiometers are widely applied to the field of radio astronomy, remote sensing, target detection and tracing, guidance, medicine etc. Synthetic aperture technology is introduced to microwave radiometer in order to improve the space resolution. Synthetic aperture radiometer (SAR) is a receiver array based on interferometry. Correlator is the key part of SAR. In early days, correlator is analog, but now it is digital.HUST communications and detection laboratory produced a synthetic aperture microwave radiometer with 16 channel array. The correlator of the radiometer is digital. It is carried out by high-speed data acquisition.The requirement analyse of high-speed synchronous data acquisition system is introduced in this paper. The high-speed synchronous data acquisition system is come true by using NI PXI-5114 two channel digtizer. Programming to the system by using LabVIEW and virtual instrument technology, the 16 channels high-speed synchronous data acquisition system is come true.Synchronous performance is a key guide line. It influences SAMR performance directly. So it was stressly investigated in this paper. The T-Clock technology which was used in this system was introduced in this paper.The sensitivity error formula of 1-D SAMR which was caused by ADC phase error was produced in theoretic. The ADC phase error of the system was tested. An ADC phase error calibration method of the system was proposed and realized. The result of calibration experiment showed that this method improved the synchronous performance.