This study addresses the detection requirements of space-based distributed radar system for high-speed maneuvering space targets. Aiming at the problems of echo range migration and Doppler crossing caused by platform spatial position difference and target high-speed maneuvering characteristics, a spatio-temporal two-dimensional coherent accumulation method for space-based distributed radar is proposed. Based on the spatio-temporal phase history of target echoes, the algorithm designs a spatio-temporal joint compensation function between and within distributed radar nodes and incorporates the node spatial synthesis compensation and intra-channel target motion compensation into a unified processing framework. Firstly, an equivalent compensation function model is established under the distributed one transmitter and multi-receiver configuration, emulating a monostatic transceiver mode. Through envelope range correction and spatial phase difference compensation, the echo time-domain process of distributed nodes is completely unified, so as to achieve spatial coherent accumulation. Secondly, the time domain two-dimensional walk correction of the target echo in the node is carried out to realize the time domain pulse coherent accumulation of the high-speed maneuvering target. To enhance the computational efficiency, on the basis of generalized Radon-Fourier transform (GRFT), the target coherent accumulation problem is transformed into parameter estimation problems such as target angle, velocity, and acceleration, thereby the accumulation detection of space-based distributed radar for space targets is realized. Finally, the effectiveness of the method is evaluated by simulation experiments. The simulation results show that the method can accurately estimate the target parameters, and the coherent accumulation gain is consistent with the theoretical analysis.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |