Making Sense of Collimators in the Testing of Imaging Systems
Testing the performance of imaging systems such as forward looking infrared radiometers (FLIR) is a vital task in the field of avionics, whether we’re talking about military or any other aircraft. The best way to examine the function of an imaging system is to use a systematized approach that can nevertheless be customized when necessary. When collimators are integrated with sources of blackbody radiation, and a target wheel is added to the focal plane, you end up with a reliable and repeatable method of testing. However, before you can use any given system, you must understand something of how it works.
A Guide to the Basic Structure of Collimators
Ahead of considering the function of collimators, we must first think about their structure. As with all things, the structure of a piece of equipment has a direct link to its function, and this must be understood. Collimators used in avionics for the purpose of calibrating imaging systems all possess the qualities outlined below:
They tend to be cylindrical in nature, containing a convex lens and an adjustable aperture, each at opposite ends of the tube. Light enters this aperture before the photons are rearranged and allowed to leave the device in a parallel formation.
All such objects contain a high reflectivity mirror to enable the conversion of scattered beams of light into an organized parallel arrangement. The accuracy of this process is partly what allows the testing process to be standardized in the way that it is.
Infrared imaging systems like FLIR are used in a wide range of ambient temperatures, and collimators can be operated in such a way as to test for proper imaging function in temperatures up to 100 degrees Celsius.
These devices tend to be portable in nature despite being rather sturdy so that you can carry out your testing regimen wherever you happen to be.
The Main Reasons for Using a Collimator
The most important reason for using such a device in the field of avionics is to test, calibrate and measure the function of imaging systems such as FLIR. Ultimately, the purpose is to see whether all the elements are properly aligned on the correct optimal axis. Once this has been successfully achieved, the aforementioned elements can be set at the right level of focus.
You can even use testing equipment like this in order to compare the function of multiple devices in combination with each other. This is of particular use in military avionics when imaging systems are linked up to weapons systems. After all, you want to be able to trust that you’re going to hit the right target based on the information displayed by your images.
Another way a collimator can be used in the field of aviation is for the purpose of training pilots in flight simulators. When you place targets that have been projected to infinity in the focal plane, it looks like they have been put in the far field.
An Essential Part of FLIR Testing
The whole point of using collimators is to test the performance of FLIR systems in a standardized and thus repeatable way. This is done by projecting patterns of electromagnetic radiation in such a manner that it appears to be coming from very large distances that are vast enough to be conveniently assigned to be infinite. The properties of these devices facilitate a wide range of functions that are essential to imaging in avionics and aviation in general.