12 - Maximum IR Detection Range

Question 1

What does Max IR Detection Range require?

Answer 1

Requires both:
- Visual LOS (R_LOS(V))
- IR Max Range (R_{Max IR})

Question 2

Low-Level-Light (LLL) Systems

Answer 2

• Enhances existing light
• Requires some illumination
• Do not work in total darkness
• Saturate if too much light is present
• Resolution determined by # and size of elements

Question 3

Light Amplification requires __

Answer 3

Ambient light

Reflected light (usually from the moon)

Question 4

Types of Infrared Systems

Answer 4

• Targeting / Navigation
• Thermal Imagers
• IR Seekers

Question 5

IR Sensor Basics

Answer 5

1. Requires no visible light
2. Detect IR energy emitted from targets
   - Passive
   - Passive = Covert
3. Background limited
4. Noise limited

Question 6

What is Background Limited?

Answer 6

Predominant source of noise is the environment

Lack of contrast between target and background

Question 7

What is Noise Limited?

Answer 7

Predominant source of noise is the detector itself masking the target signal

Sensor’s internal heat masks signature of target

Question 8

Thermal Imagers info

Answer 8

• See both emitted radiation & reflected radiation
• Rely on M_contrast

Hotspots

Question 9

What is Spatial resolution?

Answer 9

Imaging system’s ability to distinguish separate objects

Question 10

What is Thermal resolution?

Answer 10

Ability to detect small variations in temperature differences.

Small changes will not be detected

Question 11

What is Thermal Mass?

Answer 11

Energy absorbed by an object

Small thermal mass = fast temp change (small rock)
Large thermal mass = slow temp change (ships or tanks)

Question 12

What is Thermal Crossover?

Answer 12

When the environmental heating cycle causes target temp = environment temperature

No contrast