| 摘要: |
| 8 mm磁控管发射样本中频信号的起始相位随机分布，脉间频率抖动范围为±2 MHz
，脉内频率变化为500 kHz。为了克服这些问题，提出了一种适合于国内第一套毫米波
脉冲
磁控管测云雷达的测速多普勒化算法，幅度信息从回波数字下变频经低通滤波器后直接提取
, 相位信息由零中频回波IQ信号与发射样本IQ信号进行复卷积提取，并算法仿真结果表明多
普
勒频率误差不超过4 Hz。基于FPGA技术实现了测速多普勒化算法，利用高速缓存的设计
思想
实现了复卷器的优化，利用CORDIC算法实现了幅度与相位的高精度提取，并完成了算法在实
际
雷达系统中的测试,雷达的脉冲重复频率为1 000 Hz，多普勒频率在-496～500 H
z范围内，雷
达终端显示的速度值与理论值一致；回波信号幅度值为-76～6 dBm，得到的速度值
与理论值
一致。经过该算法处理的地物杂波回波的多普勒速度在零值附近分布，云体目标的回波速度
图清晰可见。该算法已经成功应用于8 mm脉冲磁控管测云雷达系统。 |
| 关键词: 测云雷达 8mm脉冲磁控管 测速多普勒化 接收相参处理 |
| DOI： |
|
| 基金项目:中国气象局-成都信息工程学院局校合作项目 |
|
| Dopplerizing an 8 mm Pulsed Magnetron Cloud Radar |
| XU Zhi-huo,HE Jian-xin |
| (Department of Electronic Engineering，Chengdu University of Information Technology，Chengdu 610225,China) |
| Abstract: |
| Transmitter sample IF（Intermediate Frequency） signal of 8mm pulsed m
agnetron has a random starting phase. Its frequency chirps at ±2 M
Hz
during pulse, and 500 kHz in pulse. To overcome these problems, a novel modi
fied
coherentonreceiving processing algorithm is presented for the first set of d
omes
tic pulsed magnetron MMW(Millimeter Wave) cloud radar. The amplitude information
is extracted directly after a lowpass filter(LPF). The phase information extr
a
ction is from convolution processing between zero IF echo IQ signal and transmit
ter IQ sample signal. The algorithm simulation results show that D
oppler frequency error is less than 4 Hz. The algorithm is implemented based
on F
PGA. The complexity convolution processor is optimized by designing high speed c
aches. High precision amplitude and phase extraction processing are realized wit
h Coordinate Rotation Digital Computer (CORDIC) algorithm. The test of the algor
ithm in actu
al radar system is also completed. When radar pulse repetition frequency
(RPF) is 1 000 Hz, Doppler frequency in -496～500 Hz, radar terminal
velocity value is correct in theory. Echo signal amplitude values in -76～6
dBm, the calc
ulate
d velocity value conforms to the theoretical one. Processing ground clutters by
this algorithm show that the velocity of the return signal is disturbed near zer
o, the echo velocity pictures of cloud targets are available. The modified coher
entonreceiving processing unit has been used in 8 mm pulsed magnetron cloud
radar system. |
| Key words: cloud radar 8 mm pulsed magnetron dopplerizing algorithm coherent on receivi
ng processing |
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