This article provides an explanation of target localization using pulse radar and the corresponding MATLAB example.

Table of Contents

• Explanation of Pulse Radar Target Localization
• Results
• Code Explanation
• Basic Principles
• Key Steps in Pulse Radar Target Localization
• MATLAB Example

Explanation of Pulse Radar Target Localization

Pulse radar is a system that detects and locates targets by emitting electromagnetic pulses and receiving the reflected echoes. Its basic working principle is to calculate the distance, azimuth, and velocity information of the target based on the time and energy changes of the electromagnetic wave propagation.

Results

Illustration of localization results:Command line screenshot:

Code structure:

Code Explanation

1. Parameter Settings

• Defines the basic parameters of the radar, including carrier frequency, pulse repetition interval, sampling rate, pulse width, etc.
• Sets the target distance and signal-to-noise ratio.

Signal Generation

• Uses a linear frequency modulation (LFM) signal as the transmitted signal of the pulse radar.

Target Echo Signal Simulation

• Calculates the echo delay based on the target distance, delays the transmitted signal, and adds noise to simulate the received echo signal.

Matched Filtering Processing

• Uses a matched filter to extract the peak position of the echo signal, thereby calculating the target’s delay and distance.

Visualization

• Plots the amplitude of the received signal and the output signal of the matched filter for easy observation of signal characteristics.

Basic Principles

1. Target Distance MeasurementBy measuring the time difference (i.e., echo delay) between the radar’s emitted pulse signal and the received echo signal, combined with the speed of electromagnetic wave propagationcc, the target distance can be calculated.

2. Target Azimuth MeasurementCalculates the direction angle (azimuth and elevation) of the target based on the beam direction angle of the antenna or the phase difference of signals received by multiple antennas.

Target Velocity MeasurementUtilizes the Doppler effect to measure the radial velocity of the target.vr

Key Steps in Pulse Radar Target Localization

1. Send pulse signals (usually linear frequency modulation signals).
2. Receive echo signals and perform matched filtering processing.
3. Extract the delay, amplitude, and Doppler frequency shift of the echo signal.
4. Calculate the target distance based on the delay, the target speed based on the Doppler frequency shift, and the target azimuth based on the antenna direction angle.

MATLAB Example

% Pulse radar, TDOA-based target localization, MATLAB code, localization in 3D space with four anchors
% Author WeChat: matlabfilter, for customized localization and navigation programs
% 2025-05-28/Ver1
clc; clear; close all;
rng(0);

%% Parameter Definition
c =3e8;% Wave speed (m/s)
fs =1e10;% Sampling rate (Hz)
pulse_width =1e-5;% Pulse width (s)
f0 =1e5;% Signal center frequency (Hz)
SNR =10;% Signal-to-noise ratio (dB)

% Anchor coordinates (four anchors)
anchors =[
1,0,0;% Anchor 1
10,1,0;% Anchor 2
0,10,1;% Anchor 3
0,0,10% Anchor 4
];

% Target point
target =[5,5,5];

% Calculate true distances
[distances]=sqrt(sum((anchors - target).^2,2));% Distance (m)

% distances/c*2

Download link for the complete code:

https://mbd.pub/o/bread/YZWTm5dpaQ==

<span>If you need assistance or have custom code requirements related to navigation and localization filtering, please contact the author via WeChat below.</span>

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