Real-time range gate control of a satellite laser ranging system based the on heterogeneous processor architecture.
The range gate generator (RGG) is a key device in kilohertz (kHz) satellite laser ranging systems. The RGG at Changchun station is an integrated circuit composed of discrete components. Using this RGG at high repetition rates can result in the loss of data, and the low resolution of internal time can lead to inaccurate data points. In this paper, starting from the principle of noise suppression by range gate control, we propose a method of range gate control with high repetition rates, high accuracy, and strong universality, and we implement a RGG based on the heterogeneous system architecture of a field-programmable gate array plus a digital signal processor. The average of the intervals between the internal time of the embedded RGG and the external standard time is 48.268 ns, and the accuracy of the range gate time is less than 1.5 ns. The test results indicate that the embedded RGG can satisfy the demand for centimeter-level accuracy with satellite laser ranging. Compared with the original RGG at Changchun station, the embedded RGG has significantly improved time resolution, repetition rate of laser ranging, and system upgrade and maintenance. At present, Changchun station is carrying out a short-term stability test on the embedded RGG.