How do you calculate cross range resolution?

How do you calculate cross range resolution?

If the range from the radar to the ground surface is 20 km, the cross-range resolution will be Δx = R × Δθ = 20000 × 0. 0375 = 750 m, much greater than the range resolution, which is equal to ΔR ≅ c/2B = 15 m. The cross-range resolution can be greatly improved by using the synthetic aperture technique.

What is range resolution in SAR?

The ERS SAR has a bandwidth of 15.6 MHz, an antenna length of 10 m and a look angle of 23◦. Accordingly the ground range resolution is about 25 m and the maximum azimuth resolution is 5 m. In practice, one averages several “looks” together to improve the quality of the amplitude (backscatter) image.

What is G in radar equation?

Radar and Inverse Scattering A radar equation relates the range of a radar to the characteristics of the transmitter, receiver, antenna, target, and distance. Consider a monostatic radar. Let Pt be the transmitted power, G the antenna gain, R the distance of the target.

How is radar range of resolution calculated?

Range resolution as a distance can be calculated as follows: Rres = c * τ /2 Where, τ is the transmitted pulse width and c is the velocity of light in the free space. Narrower beamwidth is very useful to distinguish two adjacent targets.

What is cross range resolution?

Cross Range Resolution | What is Cross Range Resolution of Radar. This is ability of radar to differentiate multiple objects or targets present at the same range. It has limited dimension which is perpendicular to radar antenna axis.

What is minimum range and pulse length?

The pulse width (H) determines the minimum range at which targets can be detected. This minimum range is approximately ½ the length of the wave burst. In the case of the 4.5µS pulse, the minimum range would be 675 meters (2,215 feet). This is also equal to approximately 0.36 nautical mile.

Is SAR resolution independent of range?

A short pulse is emitted by the antenna and then the amplitude and phase of the backscattered signal is recorded as a function of time. This is repeated over again while the platform is moving, and a 2-dimensional image is thus generated. The SAR spatial resolution is independent of the platform height.

What is basic radar equation?

Standard Form of Radar Range Equation We will get the following equation, by substituting R=RMax and Pr=Smin in Equation 6. RMax=[PtGσAe(4π)2Smin]1/4Equation7. Equation 7 represents the standard form of Radar range equation.

What is minimum range in radar?

How is the cross range resolution of a SAR determined?

(18 ) which is also termed the cross -range resolution of the SAR. This equation indicates that the cross -range resolution of a SAR can be made arbitrarily small (fine) by increasing the length of the SAR array. In theory, this is true for a spotlight SAR.

How is SAR resolution independent of platform height?

The SAR spatial resolution is independent of the platform height. This is remarkable and unique for SAR instruments. In range Xr = c t/2sin (where c: speed of light, t: pulse length, incidence angle) In azimuth Xa = D/2 (D = antenna length)

How is range compression used in the SAR processor?

In the SAR processor these frequency modulated signals are used to improve the resolutions in range X r and azimuth X a. This is called range compression and azimuth compression, respectively. Therefore the SAR processor consists essentially of 2 correlators, one for range and one for azimuth. X a = D/2 X r = c t/2sin = c/2Bsin Processing

Which is the correct form of the radar range equation?

2.2 BASIC RADAR RANGE EQUATION One form of the basic radar range equation is 2 3 4 40 S T T R N n P P G G SNR P R kT BF L (2-1) where SNRis termed the signal-to-noise ratio and has the units of watts/watt, or w/w.  P S is the signal power at some point in the radar receiver – usually at the output of the matched filter or the signal processor.

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How do you calculate cross range resolution? If the range from the radar to the ground surface is 20 km, the cross-range resolution will be Δx = R × Δθ = 20000 × 0. 0375 = 750 m, much greater than the range resolution, which is equal to ΔR ≅ c/2B = 15 m. The…