Low-altitude target detecting system of three-coordinate continuous wave one-dimensional phase sweeping unmanned aerial vehicle

Abstract

The invention discloses a low-altitude target detecting system of a three-coordinate continuous wave one-dimensional phase sweeping unmanned aerial vehicle, and is aimed at providing a detecting device high in data detecting rate and anti-interference capacity. By means of the technical scheme, the system measures a target distance through a frequency modulation continuous wave ranging system, anantenna feedback subsystem converts radio frequency signals into electromagnetic wave signals to be radiated to the space, a receiving subsystem conducts amplifying, frequency varying and SFC controlprocessing on echo signals output by an emission and wave control subsystem, a signal processing subsystem generates the working time sequence of the whole system, measures the three-coordinate vectors of the distance, direction and pitching of a target position and calculates frequency modulation continuous wave ranging data of target signals, and a data processing and communication control subsystem parses the target angle, establishes the trajectory of target movement, controls the working mode of a radar and detects three-coordinate target information according to the target signals calculated by the signal processing subsystem and the antenna angle information output by the antenna control subsystem.

Description

technical field [0001] The invention relates to a three-coordinate continuous wave one-dimensional phase-scan detection system for low-altitude and ultra-low-altitude targets. Especially for the three-coordinate continuous wave one-dimensional phase-scan detection of "low, small and slow" UAV targets. Background technique [0002] Unmanned aerial vehicles (UAVs) belong to a kind of flying objects in the category of general aircraft targets, and there are many types currently being developed. UAVs similar to multi-rotors have been widely popular among the people due to their low price and easy control, and the number has exploded. However, while the drone industry is booming, there are more and more chaos. Many problems such as the use authority of drones and the safety of low-altitude small targets have begun to appear. The monitoring and control of general-purpose aircraft in low-altitude airspace is a worldwide issue. problem. Due to the lack of effective control, "blac...

AI Technical Summary

Problems solved by technology

Low-altitude targets generally fly close to the ground and have a low altitude, so that the target echo signal received by the radar contains a lot of background noise, which greatly reduces the ability of the radar to detect, and sometimes even misjudges and loses the detection of low-altitude and ultra-low-altitude flying targets capability, which brings difficulties and threats to radar detection and survival

When detecting and tracking in the low-altitude field, the radar needs to emit a beam with sufficient energy, which will inevitably cause extremely strong ground-sea clutter, resulting in a decrease in the signal-to-clutter ratio

In addition, low-altitude targets are also affected by multipath effects, which makes the echo signal received by the radar usually a superposition of the direct wave signal and the reflected wave signal. The superimposed vector sum may be enhanced or attenuated, which is extremely unfavorable for detection performance improvement

At the same time, the angle difference between the direct wave and the image echo is very small, and the two are in the same receiving beam of the antenna, and they are a group of strongly coherent signals, which makes the angle measurement problem even more difficult

Therefore, for low-altitude targets, it is a very challenging task to solve the detection and tracking problems

The accumulated number of target echoes obtained is related to the spatial position of the echoes, which makes the spatial energy distribution uneven and causes beam splitting, which brings difficulty to target detection.

In addition, since the same batch of targets may be detected by a single or multiple oblique nods, resulting in a split in azimuth, and the target may be at the critical point of the upper and lower beams, resulting in a split in elevation

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