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radareqpow

Peak power estimate from radar equation

Since R2021a

Description

Pt = radareqpow(lambda,tgtrng,SNR,tau) estimates the peak transmit power, Pt, required for a radar operating at a wavelength of lambda meters to achieve the specified signal-to-noise ratio, SNR, in decibels for a target at a range of tgtrng meters. tau is the pulse width. The target has a nonfluctuating radar cross section (RCS) of 1 square meter.

example

Pt = radareqpow(lambda,tgtrng,SNR,tau,Name,Value) estimates the required peak transmit power with additional options specified by one or more Name,Value pair arguments.

example

Examples

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Estimate the required peak transmit power required to achieve a minimum SNR of 6 dB for a target at a range of 50 km. The target has a nonfluctuating RCS of 1 m². The radar operating frequency is 1 GHz. The pulse duration is 1 μs.

fc = 1.0e9;
lambda = physconst('LightSpeed')/fc;
tgtrng = 50e3;
tau = 1e-6;
SNR = 6;
Pt = radareqpow(lambda,tgtrng,SNR,tau)
Pt = 
2.1996e+05

Estimate the required peak transmit power required to achieve a minimum SNR of 10 dB for a target with an RCS of 0.5 m² at a range of 50 km. The radar operating frequency is 10 GHz. The pulse duration is 1 μs. Assume a transmit and receive gain of 30 dB and an overall loss factor of 3 dB. The system temperature is 300 K.

fc = 10.0e9;
lambda = physconst('LightSpeed')/fc;
Pt = radareqpow(lambda,50e3,10,1e-6,'RCS',0.5, ...
    'Gain',30,'Ts',300,'Loss',3)
Pt = 
2.2809e+06

Estimate the required peak transmit power for a bistatic radar to achieve a minimum SNR of 6 dB for a target with an RCS of 1 m². The target is 50 km from the transmitter and 75 km from the receiver. The radar operating frequency is 10 GHz and the pulse duration is 10 μs. The transmitter and receiver gains are 40 dB and 20 dB, respectively.

fc = 10.0e9;
lambda = physconst('LightSpeed')/fc;
SNR = 6;
tau = 10e-6;
TxRng = 50e3;
RvRng = 75e3;
TxRvRng =[TxRng RvRng];
TxGain = 40;
RvGain = 20;
Gain = [TxGain RvGain];
Pt = radareqpow(lambda,TxRvRng,SNR,tau,'Gain',Gain)
Pt = 
4.9492e+04

Input Arguments

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Wavelength of radar operating frequency, specified as a positive scalar. The wavelength is the ratio of the wave propagation speed to frequency. Units are in meters. For electromagnetic waves, the speed of propagation is the speed of light. Denoting the speed of light by c and the frequency (in hertz) of the wave by f, the equation for wavelength is:

λ=cf

Data Types: double

Target ranges for a monostatic or bistatic radar.

  • Monostatic radar - the transmitter and receiver are co-located. tgtrng is a real-valued positive scalar or length-J real-valued positive column vector. J is the number of targets.

  • Bistatic radar - the transmitter and receiver are separated. tgtrng is a 1-by-2 row vector with real-valued positive elements or a J-by-2 matrix with real-valued positive elements. J is the number of targets. Each row of tgtrng has the form [TxRng RxRng], where TxRng is the range from the transmitter to the target and RxRng is the range from the receiver to the target.

Units are in meters.

Data Types: double

Input signal-to-noise ratio (SNR) at the receiver, specified as a scalar or length-J real-valued vector. J is the number of targets. Units are in dB.

Data Types: double

Single pulse duration, specified as a positive scalar. Units are in seconds.

Data Types: double

Name-Value Arguments

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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: 'RCS',3.0

Radar cross section specified as a positive scalar or length-J vector of positive values. J is the number of targets. The target RCS is nonfluctuating (Swerling case 0). Units are in square meters.

Data Types: double

System noise temperature, specified as a positive scalar. The system noise temperature is the product of the system temperature and the noise figure. Units are in Kelvin.

Data Types: double

Transmitter and receiver gains, specified as a scalar or real-valued 1-by-2 row vector. When the transmitter and receiver are co-located (monostatic radar), Gain is a real-valued scalar. Then, the transmit and receive gains are equal. When the transmitter and receiver are not co-located (bistatic radar), Gain is a 1-by-2 row vector with real-valued elements. If Gain is a two-element row vector it has the form [TxGain RxGain] representing the transmit antenna and receive antenna gains. Units are in dB.

Example: [15,10]

Data Types: double

System losses, specified as a scalar. Units are in dB.

Example: 1

Data Types: double

Atmospheric absorption losses for the transmit and receive paths.

  • When the absorption is a scalar or length-J column vector, the loss specifies the atmospheric absorption loss for a one-way path.

  • When the absorption is a 1-by-2 row vector or J-by-2 column vector, the first column specifies the atmospheric absorption loss for the transmit path and the second column of contains the atmospheric absorption loss for the receive path

Example: [10,20]

Data Types: double

Propagation factor for the transmit and receive paths.

  • When the propagation factor is a scalar or length-J column vector, the propagation factor is specified for a one-way path.

  • When the propagation factor is a 1-by-2 row vector or J-by-2 column vector, the first column specifies the propagation factor for the transmit path and the second column of contains the propagation factor for the receive path

Units are in dB.

Example: [10,20]

Data Types: double

Custom loss factors specified as a scalar or length-J column vector of real values. J is the number of targets. These factors contribute to the reduction of the received signal energy and can include range-dependent Sensitive Time Control (STC), eclipsing, and beam-dwell factors. Units are in dB.

Example: [10,20]

Data Types: double

Output Arguments

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Transmitter peak power, returned as positive scalar. Units are in watts.

More About

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References

[1] Richards, M. A. Fundamentals of Radar Signal Processing. New York: McGraw-Hill, 2005.

[2] Skolnik, M. Introduction to Radar Systems. New York: McGraw-Hill, 1980.

[3] Willis, N. J. Bistatic Radar. Raleigh, NC: SciTech Publishing, 2005.

Extended Capabilities

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Version History

Introduced in R2021a