Recommend sensors for each of the applications below. Multiple sensors may be needed. Indication how the sensor will be used; if it is active or passive, exteroceptive or proprioceptive; and detail any important characteristics when selecting the sensor.

• Detecting collisions with objects while a wheeled robot is driving
• Detecting walls inside of a building
• Determining the direction of flight in a GPS-denied environment
• Determining the location of a tractor as it plants crops
• Determining the tilt on a wheeled robot
• Estimating the acceleration a rotational velocity of a quadcopter
• Locating a fire for a flying drone with flame retardant
• Maintaining a constant distance from a wind turbine as a drone flies
• Measuring the amount a wheel rotates on a robot
• Tracking the position of a conveyor belt