What are different sensors used in autonomous vehicles and how are they categorized?

Definition of a Sensor: It is a device that measures or detects a property of the environment or changes to a property.
For example, a thermometer is a sensor that measures the temperature of the environment it is placed in.

In autonomous vehicles, there are multiple sensors installed that are used for the perception, making sense of the environment, and helping localize the vehicle in the local and global sense.
These sensors are categorized into two categories: the sensors in one category are called exteroceptive sensors, while the other category is the proprioceptive sensors.

Exteroceptive sensors: The term extero means surroundings, and this type of sensor provides information about the surroundings of the vehicle. The sensors falling into this category are:

• Camera
• Light Detection and Ranging (LiDAR)
• Radio Detection and Ranging (RADAR)
• Sound Navigation and Ranging (SONAR)

Proprioceptive sensors: The term proprio means internal and this type of sensors provide information about the vehicle itself. Following sensors are considered proprioceptive:

• Global Positioning Systems (GPS)
• Inertial Measurement Unit (IMU)
• Wheel Odometer