MAThis calculates the maximum range at which a given signal-to-noise ratio can be achieved by a radar of specified parameters. Used in conjunction with the "SNR for given Pfa and Pd" function, this function allows the user to determine the range at which a radar will achiev the desired Pfa and Pd. It uses equation 2.33 of Skolnik.
AThis function calculates the beamwidth of the antenna given its length in the plane of the angle. This function assumes a cos2 distribution of energy across the aperture, and uses Table 7.1 of Skolnik to determine the beamwidth.
"Save as azimuth" and "Save as elevation" save the resulting beamwidth as the azimuth and elevation 3dB beamwidth respectively, for use in subsequent calculations.
}AThis function calculates the gain of an antenna in dB (with respect to an isotropic antenna), given the 3dB azimuth and elevation beamwidths (in degrees). This is calculated using equatiob 7.5a of Skolnik.
"Save as Gt" and "Save as Gr" save the resulting gain as the transmit and receive antenna gains respectively. This allows the result to be used in subsequent calculations.
AThe radar shown in background bitmap is known as Byson, and is an experimental 3GHz radar at the Defence Evaluation and Research Agency (DERA) in Malvern. It was originally installed in 1959 as a 2/3rds prototype of the British "Type 85" Air Defence radar. It has since been extensively modified with modern digital processing equipment, and is now available for hire for radar experimentation. Contact the author for details!
ified with modern digital processing equipment, and is now available for hire for radar experimentation. Contact the author for details!
About the radar...
OCThis function calculates the required signal-to-noise ratio (SNR) for detection of a single fluctuating pulse, given a probability of false alarm (Pfa) and probability of detection (Pd). It also calculates the integration efficiency corresponding to the non-coherent integration of n pulses.
The calculation is in three steps:
1. Calculation of SNR
for detection of a sinewave, given Pfa and Pd. This uses Figure 2.7 of Skolnik.
2. Calculation of additional SNR required for detection of a single fluctuating pulse, with the required Pfa and Pd. This uses Figure 2.23 of Skolnik.
3. Calculation of the integration efficiency, Ei(n), assuming n pulses are non-coherently integrated. This is a strong function of both Pfa and Swerling type and is calculated from Figure 2.24 of Skolnik. For coherent integration, assume an efficiency of 1.
"ARadCalc was written by Dr Paul E Howland. Bug reports or suggestions for future releases may be emailed to PEHowland@iee.org.uk.
Whilst every care has been taken to ensure the results of this program are accurate, I accept absolutely no responsibility for the consequences of any errors!
AThis assumes a surveillance radar with a given solid angle beamwidth which is required to survey a certain azimuthal sector, between a minimum and maximum elevation angles, in a fixed surveillance time. Given the radar pulse repetition frequency this function calculates the number of pulses that are transmitted in each dwell position. This can then be used in the radar equation to calculate the maximum range of the radar.
Equation 1.81 of Meyer and Mayer is used to calculate this.
A(c) Paul E Howland, 1998
RadCalc is designed to perform a variety of simple calculations to determine the performance of radar systems. The majority of the formulae used in this program are taken from "Introduction to radar systems", by Merrill I Skolnik, 2nd Edition, 1981, Artech House Books.
The use of the skeleton event handler provided by RMR Software is gratefully acknowledged. Visit www.rmrsoft.com to see whatelse they have on offer!
About RadCalc v1.6?
Bug fixes and suggestions
Range/bearing between points
This option calculates the range and bearing of one point from another point. The location of each point is specified as a latitude and longitude in decimal degrees. The answer is returned in kilometres and decimal degrees.
Point at specified range/bearingtThis function calculates the latitude and longitude of a point at a specified range and bearing from another point.
Maximum line-of-sight range
Given a radar height and target altitude, this function calculates the maximum range at which the target is line-of-sight of the radar. The function uses 4/3rds earth radius to model atmospheric refraction, and assumes a smooth, spherical earth.
Wavelength given frequencyxThis function calculates the free space wavelength of the radar signal (in metres), given the radar frequency (in MHz).
Gain given beamwidths
Gain given effective aperture
This function calculates the gain of antenna given the radar frequency (in MHz), the physical area of the aperture (in m2) and the antenna efficiency. This is calculated using equation 7.9 of Skolnik.
Beamwidth given dimensions
Angular accuracy
This function calculates the rms angular error of an antenna, given its 3dB beamwidth and IF signal-to-noise ratio. A
rectangular distribution of energy is assumed. The error is calculated using equation 11.42b of Skolnik.
Range resolutionWThis function calculates the range resolution of the radar given its bandwidth in MHz.
Unambiguous range
This function calculates the unambiguous range of the radar given the pulse repetition frequency in Hz. This uses equation 1.2 of Skolnik.
Range accuracy
This function calculates the rms range error of the radar given the waveform bandwidth (in MHz) and the IF signal-to-noise ratio. The calculation assumes a Gaussian pulse, and uses equation 11.25 of Skolnik.
SNR for given Pfa and Pd
Skolnik
Introduction to radar systems,
Merril I Skolnik, Second Edition, Artech House Books, 1981.
ISBN 0-07-Y66572-9.
A must for all radar engineers.
Maximum range for given SNR
AThis software is SHAREWARE.
If this software is only used for personal purposes, for no profit, then it may be used for free.
If this software is used during the course of your work, or for any other commercial purpose, please arrange for your company to send a cheque for
15 (or foreign currency of equivalent value) to Dr PE
You are permitted to distribute this software freely.
About the radar...
Solid angle given Ae
This calculates the solid angle of the radar antenna pattern, given the aperture of the antenna, its efficiency and the radar frequency. The formula
solid angle = lambda2/(aperture
efficiency)
is used.
Solid angle given beamwidths
This formula calculates the solid angle of the antenna beam given the 3dB azimuth and elevation beamwidths. The approximation solid angle = azimuth
elevation is used.
SaveWThis saves the current radar parameters, overwriting the previously loaded parameters.
Save as...7This saves the current radar parameters to a new file.
Load=This loads the radar parameters of a previously saved radar.
Number of pulses per dwell
Meyer and Mayer
Radar Target Detection, handbook of theory and practice, Daniel Meyer and Herbert Mayer, Academic Press Inc, 1973. ISBN 0-12-492850-1.
The reference for radar detection calculations.
Radar band conversionszThis function allows you to convert between frequency and the NATO, UK IEE and US band designations, in either direction.
5 Licensing
Times New Roman
PBThis software is SHAREWARE.
If this software is only used for personal purposes, for no profit, then it may be used for free.
If this software is used during the course of your work, or for any other commercial purpose, please arrange for your company to send a cheque for
15 (or foreign currency of equivalent value) to Dr PE
Howland, 52 Lower Chestnut Street, Worcester, WR1 1PD, UK. This entitles you to free upgrades by email as and when new versions of the software are released.
You are not permitted to resell this software.
You are permitted to distribute this software freely.
About the radar...
Solid angle given Ae
This calculates the solid angle of the radar antenna pattern, given the aperture of the antenna, its efficiency and the radar frequency. The formula
solid angle = lambda2/(aperture
efficiency)
is used.
Solid angle given beamwidths
This formula calculates the solid angle of the antenna beam given the 3dB azimuth and elevation beamwidths. The approximation solid angle = azimuth
elevation is used.
SaveWThis saves the current radar parameters, overwriting the previously loaded parameters.
Save as...7This saves the current radar parameters to a new file.
Load=This loads the radar parameters of a previously saved radar.
Number of pulses per dwell
Meyer and Mayer
Radar Target Detection, handbook of theory and practice, Daniel Meyer and Herbert Mayer, Academic Press Inc, 1973. ISBN 0-12-492850-1.
The reference for radar detection calculations.
Radar band conversionszThis function allows you to convert between frequency and the NATO, UK IEE and US band designations, in either direction.
5 Licensing
Times New Roman
About the radar...
Solid angle given Ae
This calculates the solid angle of the radar antenna pattern, given the aperture of the antenna, its efficiency and the radar frequency. The formula
solid angle = lambda2/(aperture
efficiency)
is used.
Solid angle given beamwidths
This formula calculates the solid angle of the antenna beam given the 3dB azimuth and elevation beamwidths. The approximation solid angle = azimuth
elevation is used.
SaveWThis saves the current radar parameters, overwriting the previously loaded parameters.
Save as...7This saves the current radar parameters to a new file.
Load=This loads the radar parameters of a previously saved radar.
Number of pulses per dwell
Meyer and Mayer
Radar Target Detection, handbook of theory and practice, Daniel Meyer and Herbert Mayer, Academic Press Inc, 1973. ISBN 0-12-492850-1.
The reference for radar detection calculations.
Radar band conversionszThis function allows you to convert between frequency and the NATO, UK IEE and US band designations, in either direction.
5 Licensing
Times New Roman
Frequency given wavelengthxThis function calculates the frequency of the radar signal (in MHz), given the radar free space wavelength (in metres).
A(c) Paul E Howland, 1998
RadCalc is designed to perform a variety of simple calculations to determine the performance of radar systems. The majority of the formulae used in this program are taken from "Introduction to radar systems", by Merrill I Skolnik, 2nd Edition, 1981, Artech House Books.
The use of the skeleton event handler provided by RMR Software is gratefully acknowledged. Visit www.rmrsoft.com to see whatelse they have on offer!
About RadCalc v1.7?
Bug fixes and suggestions
Range/bearing between points
This option calculates the range and bearing of one point from another point. The location of each point is specified as a latitude and longitude in decimal degrees. The answer is returned in kilometres and decimal degrees.
Point at specified range/bearingtThis function calculates the latitude and longitude of a point at a specified range and bearing from another point.
Maximum line-of-sight range
Given a radar height and target altitude, this function calculates the maximum range at which the target is line-of-sight of the radar. The function uses 4/3rds earth radius to model atmospheric refraction, and assumes a smooth, spherical earth.
Wavelength given frequencyxThis function calcula
tes the free space wavelength of the radar signal (in metres), given the radar frequency (in MHz).
Gain given beamwidths
Gain given effective aperture
This function calculates the gain of antenna given the radar frequency (in MHz), the physical area of the aperture (in m2) and the antenna efficiency. This is calculated using equation 7.9 of Skolnik.
Beamwidth given dimensions
Angular accuracy
This function calculates the rms angular error of an antenna, given its 3dB beamwidth and IF signal-to-noise ratio. A
rectangular distribution of energy is assumed. The error is calculated using equation 11.42b of Skolnik.
Range resolutionWThis function calculates the range resolution of the radar given its bandwidth in MHz.
Unambiguous range
This function calculates the unambiguous range of the radar given the pulse repetition frequency in Hz. This uses equation 1.2 of Skolnik.
Range accuracy
This function calculates the rms range error of the radar given the waveform bandwidth (in MHz) and the IF signal-to-noise ratio. The calculation assumes a Gaussian pulse, and uses equation 11.25 of Skolnik.
SNR for given Pfa and Pd
Skolnik
Introduction to radar systems,
Merril I Skolnik, Second Edition, Artech House Books, 1981.