The influence of sampling mode on the accuracy of satellite interference geolocation

There are two typical types of sampling mode in the geolocation of satellite interference: ultra-wideband sampling and narrowband sampling. Besides the measurement error, in narrowband case, the process of ephemeris correction will introduce considerable approximation error and crystal drift error in down convertor (DC), due to both the time-varying feature of ephemeris and non-synchronous sampling in geolocation. Those errors, which can be avoided by using ultra-wideband sampling mode, will impact the accuracy of ephemeris correction and then impact the accuracy of interference geolocation. This paper studies two different sampling modes, compares their differences and resemblances, and reveals the internal reasons why ultra-wideband sampling method has a better performance on dual-satellite geolocation. By analyzing the detailed flow of the ephemeris calibration algorithm, it shows that the ultrawideband sampling mode can effectively mitigate the inherent errors, and thus has a better performance on the calibration accuracy of the ephemeris than narrowband mode. Lastly, four groups of experiments are conducted: each group has different sampling time, running the same ephemeris correction algorithm in two different sampling modes. Experiments results show that the ultra-wideband sampling mode can remarkably improve the accuracy of location results, and the shorter the sampling time, the more accurate the location results. The ultra-wideband sampling technology is a major technological innovation for satellite interference location system.