CN-117031408-B - Digital radar to analog image scanning line compensation method, device and storage medium

CN117031408BCN 117031408 BCN117031408 BCN 117031408BCN-117031408-B

Abstract

The invention relates to a digital radar to analog image scanning line compensation method, a device and a storage medium, wherein the method is realized by acquiring the north orientation of a digital scanning line issued by a current digital radar and combining the north orientation of a historical digital scanning line, and calculating the theoretical stepping increment of the digital scanning line, comparing the theoretical stepping increment to judge whether the current digital scanning line needs scanning line compensation or not, and if so, carrying out scanning line compensation on the current digital scanning line according to the theoretical stepping increment. The method of the invention ensures that the wire harness of the scanning line sent by the upper computer to the lower computer is kept at 1024, and the lower computer can realize the output of 4096 azimuth pulses only by carrying out frequency multiplication processing on the corresponding azimuth pulses after receiving the scanning line issued by the upper computer, and compared with the method of the invention which has 4096 scanning lines issued by the upper computer, the data volume is small, the memory occupation is low, and the consumption of hardware resources can be reduced to 1/4.

Inventors

GAO GE
DU PENG
ZHANG ZHI
YIN SHIBO
LI CHENHAO
ZHANG QIMING
WANG HONGXIAN
WEN JIANXING
ZHAO YUNQIANG
HU JIE

Assignees

中船航海科技有限责任公司

Dates

Publication Date: 20260512
Application Date: 20230725

Claims (8)

1. The method for compensating the scanning line of the digital radar to the analog image is characterized by comprising the following steps: S1, acquiring the north orientation of a current digital scanning line by an upper computer according to data issued by a digital radar; S2, if the length of the scanning line azimuth storage queue where the current digital scanning line is positioned is smaller than n, n is more than or equal to 4, storing the north azimuth of the current digital scanning line into the scanning line azimuth storage queue; S3, the upper computer acquires the front 4 digital scanning lines of the current digital scanning line issued by the digital radar, and stores the north orientation of the front 4 digital scanning lines of the current digital scanning line in a data structure of a queue; S4, respectively calculating the step length between the north orientations of the front 4 digital scanning lines of the current digital scanning line, wherein the step length=the north orientation of the rear digital scanning line-the north orientation of the front digital scanning line, calculating to obtain the median value of the step length between the north orientations of the front 4 digital scanning lines, and taking the median value as the theoretical stepping increment of the current digital scanning line compensation; S5, compensation judgment, namely if the step length of the current north direction of the digital scanning line is greater than 0 and does not exceed a set compensation judgment value, carrying out digital scanning line compensation; s6, when the digital scanning lines are compensated, the step length of the north orientation of each compensated digital scanning line is a theoretical stepping increment, and the north orientation of the compensated digital scanning line is smaller than the north orientation of the current digital scanning line; S7, inserting the compensated north orientation of the digital scanning line into the front side of the north orientation of the current digital scanning line in a scanning line orientation storage queue where the north orientation of the current digital scanning line is located; iteratively scanning a scanning line azimuth storage queue where the current digital scanning line is located, acquiring the north azimuth of the compensated digital scanning line and the north azimuth of the current digital scanning line, and transmitting the north azimuth and the north azimuth to a lower computer; s8, the lower computer generates an analog format signal according to the received digital scanning line, multiplies the frequency of the azimuth pulse by 1:4, and outputs 4096 pulses.
2. The method for compensating for digital radar to analog image scan line according to claim 1, wherein in the step S5, if the step length of the current digital scan line north orientation is greater than the set compensation determination value, the scan line is ignored, and if the step length of the current digital scan line north orientation is less than or equal to 0, the compensation determination is performed after the modulo correction.
3. The method for compensating for a scan line of a digital radar to analog image according to claim 2, wherein in the step S5, when performing the correction of the model, a step +4096 of the north orientation of the current digital scan line is corrected.
4. The method for compensating for digital radar to analog image scan line according to claim 1, wherein in the step S6, the north orientation of the compensated digital scan line=north orientation of the previous digital scan line of the current digital scan line+theoretical step increment (i+1), i=0, 1.
5. The method for compensating for a scan line of a digital radar to analog image according to claim 1, wherein the compensation determination value = n x theoretical step increment.
6. The method for compensating scan line of digital radar to analog image according to claim 1, wherein in step S7, the 5 th digital scan line north orientation in the scan line orientation storage queue is taken each time during iterative scanning, and the first digital scan line north orientation is removed, and the length of the scan line orientation storage queue is iteratively scanned until the length is not more than 4.
7. The device for converting the digital navigation radar into the analog image is characterized by comprising the digital radar, an upper computer and a lower computer, wherein the upper computer processes the north orientation of a digital scanning line acquired from the digital radar according to the method of any one of claims 1-6 and then transmits the processed north orientation to the lower computer.
8. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a computer program which, when run, performs the steps S1-S7 of the method according to any of claims 1-6.

Description

Digital radar to analog image scanning line compensation method, device and storage medium Technical Field The invention relates to the field of radar signal processing, in particular to a method and a device for compensating a scanning line of converting a digital radar into an analog image and a storage medium, which are suitable for application scenes of converting a digital radar image into an analog format in a ship motion state. Background The radar for ship is one kind of equipment for ship navigation, surrounding environment monitoring and auxiliary collision prevention, and has directional antenna to radiate and receive electromagnetic wave, rotating antenna to complete 360 deg. detection of surrounding environment, triggering signal, bow signal, north signal, azimuth signal and video signal, analog level transmission, radar processing unit to convert the analog level signals into digital video data, and display and control terminal to complete image display. The trigger signal indicates pulse generation, the bow signal indicates that the antenna rotates to the zero position in the antenna direction, the north signal indicates that the antenna rotates to the north direction, the azimuth signal indicates all the azimuth positions of the antenna in the rotation process, and the video signal indicates an analog video image in the azimuth at the moment. Compared with the traditional radar, the digital radar integrates a radar information processing unit in a transceiver, replaces traditional trigger signals, bow signals, north-right signals, azimuth signals and video analog signals, and directly outputs radar images in a digital network format. The digital network interface replaces an analog interface, so that equipment connection is simplified, great convenience is brought to debugging and maintenance, equipment compatibility is also brought, for example, equipment such as an electronic chart and the like cannot directly receive a network video signal in a digital format along an old radar analog interface, and at the moment, requirements and use scenes are put forward for converting a digital navigation radar network format image into an analog format again. Since the network scan line of a digital radar typically has only 1000-1800 data packets per antenna rotation period, whereas the azimuth pulse signal in analog format has 4096 pulses per antenna rotation period, this means that not every analog azimuth is generated corresponding to a digital scan line. Therefore, in the process of converting digital to analog, frequency multiplication is needed for the digital scanning line to reach the count of 4096 pulses. For example, 1024 data packets in each period of a common digital radar scanning line can occupy all the orientations of analog models only by 4 times of frequency. When the ship has steering, swinging and other movements, the north signal is influenced by the ship movement to generate time offset, and the number of azimuth pulses between two north pulses is dynamically changed. Specifically, when the ship rotates clockwise, the azimuth pulses between two adjacent northlashes are reduced, namely 4096 azimuth pulses are not reached, due to the fact that the second northlashing direction arrives in advance, and when the ship rotates anticlockwise, the azimuth pulses between two adjacent northlashes are increased, namely more than 4096 azimuth pulses are reached due to the fact that the second northlashing direction delays. The traditional analog signal is characterized in that each azimuth pulse corresponds to 360/4096 approximately 0.088 degrees, the change of 24 azimuth pulses can bring an error angle of 0.088 degrees by 24-2.11 degrees, but when the analog signal is converted by adopting a digital scanning line, the error angle of 2.11 degrees is caused by only 6 digital scanning due to the existence of 4 times frequency operation, the error appears on an image that when the ship rotates clockwise, a certain small unfilled angle exists at the north of the image, the faster the rotation is, the larger the unfilled angle is, when the ship rotates anticlockwise, the smaller the rotation is, the quicker the rotation is, and the larger the rotation angle is. It is worth noting that the problem of changing the arrival time of the northbound signal in the motion scene still exists by adopting an analog signal image transmission mode, and only because the number of azimuth pulses is large, the corresponding angle of single pulse is small, and a large number of single pulses are needed to display obvious unfilled corners or rotations on the image. However, the number of the scanning lines in the digital format is small, a 4-frequency multiplication process exists, each digital scanning line corresponds to an azimuth of 0.088 degrees by 4=0.352 degrees, and even if the ship rotates at a low speed, only a few scanning lines are lost, so that obvious influence can be generated. In order to solve the a