Glossary Definition

DRI (Detection, Recognition & Identification)

Detection, Recognition, and Identification (DRI) are guidelines that have been set in place by The Night Vision Thermal Imaging Systems Performance Model, also referred to as the Johnson criteria. They are a universally accepted set of standards initially developed by the US Army to provide a means of measuring the distance whereby a thermal sensor can produce an image of a specific target.


Detection means that you will be able to see the target, however it will be little more than a spec. Specifically it means that the target is visible on at least two pixels, and that there is a good chance that the target is actually something of suspicion.


Contrary to what might be expected, recognition does not mean that you can recognize an individual. Recognition simply means that you are able to recognize an object’s class (is it a human or a car, is it a truck or a tank, etc).


Identification of an object means that you are able to differentiate between objects. For example, being able to identify the type of vehicle not just its class.

The terms detection, recognition, and identification can be extremely misleading, especially to end users and the public who do not have a military or electro-optics background. They are calculated based on standards developed in the 1950s for lower resolution CRT displays. Newer high-resolution digital sensors have shrunk the perceived size of these measurements, but the standards still remain.

For a more complete explanation of DRI measurements and what to expect, please see our Whitepaper on DRI: Thermal Distance Ratings Explained.

Full Glossary