A Wide Range Distributed Multi-Node Receive Chain Calibration Method Based on GNSS Software Receiver

The phase calibration of distributed multi-node receiving system is required considering the phase synthesis working mode of distributed radar system for echo signals. Whereas, in respect to the traditional calibration tower and unmanned aerial vehicle scheme, there are many disadvantages. The wide range distributed multi-node receive chain calibration method based on GNSS software receiver was proposed in this paper, taking advantage of the software receiver to calculate and obtain the actual phase difference among the receiving nodes as well as the coordinate information of satellites in transmitting signal. Therefore, the phase difference resulted from different transmit path can be deleted, and the phase inconsistencies among the receiving nodes can be obtained. Besides, the fingerprint maps database regarding inconsistencies among nodes and two-dimensional angle of relative receiving node for satellites was constructed in this paper, the correspondence between the omnidirectional two-dimensional angle and the inconsistencies among different nodes was established by the actual results and two-dimensional fitting, and the phase inconsistency results among nodes can be obtained only by solving the satellite coordinate information. There are many advantages for the method proposed in this paper, such as slight influence of multipath effect, capability of all-weather all-day calibration, low costs.