###### Abstract  
With the realization of global navigation satellite system (GNSS) completion, GNSS reflectometry (GNSS-R) has become increasingly popular due to the advantages of global coverage and the availability of multiple sources in terms of earth remote sensing. This paper analyzes the Beidou navigation satellite system (BDS) signal reflection detection of multiple satellites and multiple moving targets under multiple-input and multiple-output (MIMO) radar systems and proposes a series of methods to suppress multiple Doppler phase influences and improve the range detection property. The simulation results show the restored target peaks, which match the RCS data more accurately, with the GNSS-R Doppler phase influence removed, which proves the proposed method can improve target recognition and detection resolution performance. global navigation satellite system reflectometry (GNSS-R); Beidou navigation satellite system (BDS); Doppler compensation; range resolution Article  
strong clutter and noise. Reference [13] notes that for large and medium-sized targets on the sea surface, GNSS-R detection can acquire a sufficient signal-to-noise ratio (SNR) of 20-25 dB [14] after several seconds of accumulation. Next, one study in the literature [14; 15] simulated a delay-Doppler map (DDM) of large-scale targets and verified the effectiveness of large-scale target detection based on short time accumulation signals using the range-Doppler Fourier method. In terms of theoretical construction and system model, reference [16] gives an extremum approximation algorithm for advanced receiver autonomous integrity monitoring, and triple-frequency combining observation models have been studied for precise point positioning [17]. Moreover, real-time, direction-constrained determination methods were proposed for point velocity detection studies [18; 19; 20]. In order to better interpret the target information of the GNSS-R signal and obtain the images that match the detected target, many signal processing methods were proposed. The incoherent range walk compensation method was proposed for spaceborne GNSS-R imaging [3], and GNSS-R-based moving target indication is studied in the literature [21]. In terms of marine target detection, ocean surface target detection and positioning were discussed [22], the delay and Doppler tracking errors were analyzed [15], and the feasibility analysis of ship detection by DDM was simulated [23]. In order to distinguish sea targets from sea clutter, the blind sea clutter suppression method was discussed [24]. Moreover, the data of TDS-1 were used to prove the effectiveness of the proposed target detection method [25], and the anomalous artifacts of TDS-1 DDM were analyzed in [26]. In this paper, multiple-BDS signal reflection detection for multiple moving targets was studied. We propose the multiple targets Doppler compensation (MTDC) method to keep target peaks from the influence of the Doppler phase and provide a target peak identification method and range inversion methods to realize the specific scatter information detection of targets. The contributions of this paper can be summarized as follows: (1) The target peak reduction problem existing in multiple-BDS signal detection was analyzed by echo formulas, and solutions are proposed for two situations: when target estimation information is acquired and when it is not. In the simulation, a difference of more than 400 Hz in the Doppler frequency was set among the detected targets, which further verifies that the proposed method is effective; (2) The target peak identification method is proposed based on 33 m sampling at the echoes, and the improved target detection peaks can express the target information more accurately in terms of amplitude and range point; (3) A range inversion method is proposed to acquire the specific scatter information in the case of low-resolution BDS signals.