sarrange

Maximum unambiguous slant range of SAR

Since R2021a

Description

example

mur = sarrange(v,daz,df) returns the maximum unambiguous slant range of a synthetic aperture radar (SAR) system.

example

mur = sarrange(v,daz,df,Name,Value) specifies additional options using name-value arguments. Options include the Doppler cone angle and the antenna roll-off factor.

Examples

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Estimate the maximum unambiguous range of a side-looking airborne synthetic aperture radar (SAR) operating in broadside with a sensor velocity varying from 20 m/s to 300 m/s. The SAR antenna has an aperture dimension of 3 m in the azimuth direction and a transmitter that works with a 5% duty cycle. Plot the resulting unambiguous range as a function of sensor velocity.

v = 20:10:300;
daz = 3;
d = 0.05;

Compute the maximum unambiguous range in meters. Assume an antenna roll-off factor of 1.5. Convert the range to nautical miles.

Rmet = sarrange(v,daz,d,'RollOff',1.5);
Rnau = Rmet*0.00053996;

Plot the unambiguous range as a function of the sensor velocity.

loglog(v,Rnau)

axis([10 1000 100 10000])
xlabel('Velocity (m/s)')
ylabel('Unambiguous Range (nmi)')
title('Unambiguous Range Limits for 1.5 Roll-Off')

Input Arguments

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Sensor velocity in meters per second, specified as a positive real scalar or vector.

Data Types: double

Antenna width in the azimuth direction in meters, specified as a positive real scalar.

Data Types: double

Duty factor, specified as a positive real scalar in the range [0, 1] or a vector. The duty factor is defined as the ratio of the pulse width to the pulse period.

Data Types: double

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'RollOff',1.2,'ConeAngle',120

Doppler cone angle in degrees, specified as a scalar in the range [0, 180]. This argument identifies the direction toward the scene relative to the direction of motion of the array.

Data Types: double

Antenna roll-off factor, specified as a positive real scalar. This argument provides a safety factor that prevents mainlobe returns from aliasing in the pulse repetition frequency (PRF) time interval. Adjust the roll-off factor to make the PRF greater than the mainlobe Doppler bandwidth.

Data Types: double

Output Arguments

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Maximum unambiguous range, returned as a matrix. The rows of mur correspond to the velocity values in v. The columns of mur correspond to the duty factor values in df.

Version History

Introduced in R2021a