Formulas and tables of thermal imaging camera module detection range

In long range monitoring applications such as coastal defense and anti uav, we often encounter such problems: if we need to detect 20 km people and vehicles, what kind of thermal imaging camera is needed, this paper will give the answer.

In the infrared camera system, the observation level of the target is divided into three levels: detectable, recognizable and distinguishable.

When the target occupies one pixel in the detector, it is regarded as detectable; When the target occupies 4 pixels in the detector, it is regarded as recognizable;

When the target occupies 8 pixels in the detector, it is regarded as distinguishable.

L is the target size (in meters)

S is the pixel spacing of the detector (in micrometers)

F is the focal length (mm)

Detection target range = L * f / S

Recognition target distance = L * f / (4 * s)

Discrimination target distance = L * f / (8 * s)

Spatial resolution = S / F (milliradians)

Observation distance of 17um detector with different lenses

Object

Resolution 9.6mm 19mm 25mm 35mm

40mm

52 mm

75mm 100 mm

150mm

Resolution (milliradians)

1.77mrad 0.89mrad 0.68mrad 0,48mrad 0.42mrad 0.33mrad 0.23mrad 0.17mrad

0.11m rad

FOV

384×288

43.7°x32° 19.5°x24.7° 14.9°x11.2° 10.6°x8°

9.3°x7°

7.2°x5.4° 5.0°x3.7° 3.7°x2.8°

2.5°x.95

640×480

72.8°x53.4° 32.0°x24.2° 24.5°x18.5° 17.5°x13.1°

15.5°x11.6°

11.9 x 9.0° 8.3°x6.2° 6.2°x4.7°

4.2°x3.1°

 

Discrimination

31m 65m 90m 126m

145 m

190m

275m 360m

550m

Person

Recognition

62m 130m 180m 252m

290m

380m

550m 730m

1100m

  Detection

261m 550m 735m 1030m

1170m

1520m

2200m

2940 m

4410m

 

Discrimination

152 m 320m 422m 590m

670m

875m

1260m

1690m

2530m

Car

Recognition

303m 640m 845m 1180m

1350m

1750m

2500m

3380m

5070m

  Detection 1217m 2570m 3380m 4730m

5400m

7030m

10000m 13500m

20290m

If the object to be detected is UAV or pyrotechnic target, it can also be calculated according to the above method.

Usually, thermal imaging camera will work together with long range IP zoom block camera module and laser ranging, and be used for heavy-duty PTZ camera and other products.


Post time: May-20-2021