IMU

Inertia Measurement Unit detects directional force such as acceleration, pitch and yaw. Typically used to augment signals from satellite navigation sensors (GPS / GNSS) when signals are unavailable (under tunnels, bridges) or need correction (atmospheric noise, urban canyon effect, etc).

Infrared

Part of the electromagnetic spectrum invisible to the human eye but can usually be detected by video cameras. Used to aid night vision and enabled the laser ranging of LiDAR sensors.

ISP

Integrated Signal Processor – a dedicated semiconductor, typically part of the camera module which provides high speed low latency processing directly on the raw data from the camera chip.