UAS Sensors

In this section, we will go over the types of UAS sensors and their different applications.

True Color or RGB

These sensors collect three bands for each image, red, green and blue, all of which are on the visible light spectrum.

Thermal

These sensors detect infrared radiation emitted from objects.

Multispectral

These sensors collect data across multiple spectral bands, these include visible and non-visible light. Typically, these bands are specific so users must be aware of the data needed to capture when considering these sensors.

Light Detection and Ranging (LiDAR)

These sensors use pulses of light as lasers to measure distances. These pulses can have multiple returns so it can show canopy cover as well as forest floor from a single flight. LiDAR data products are in the form of point clouds that can then be converted to digital elevation models.

Global Shutter vs. Rolling Shutter

This refers to the way that the sensor/camera captures data, it can also be referred to as the exposure method. Rolling shutters capture data by exposing the sensor’s pixels row by row, the top of the image is exposed slightly before the bottom of the image. A global shutter, also known as a mechanical shutter, captures all pixels at once. Global shutters are more ideal for photogrammetry as there will be less blur in the images. There are settings in the photogrammetry software that can correct for rolling shutters but even with the correction products do not come out as well.