Let’s face it, digital camera sensors are measured in ridiculous ways. If you’re trying to make sense of what dimension a 1/2.8" sensor size is referring to, or if you’re wondering how thermal imaging sensor measurements are different, you’ve come to the right place.

The DORI (Detection, Observation, Recognition, Identification) standard is based on the IEC EN62676-4: 2015 International Standard. Unlike DRI (also known as the Johnson Criteria) for thermal cameras, DORI is designed for visible light surveillance cameras and uses specific measurements in PPM (Pixels Per Meter) to define what Detection (25PPM), Observation (62PPM), Recognition (125PPM), and Identification (250PPM) are for standard color cameras.

If you’ve done any research comparing thermal cameras, you’re likely to have come across the term “DRI”, which is often used to compare performance between thermal imaging cameras. DRI stands for Detection, Recognition and Identification, however it’s important to understand how those terms are defined, as they’re likely to mislead many customers with unrealistic expectations.

Laser rangefinders use advanced technology developed for the military to accurately measure the distance to a target. LRFs work by pulsing a SWIR laser towards a target, and a receiver then detects the reflection of that light and accurately calculates the distance based on the time it took for the light to bounce back.

RTSP (Real Time Streaming Protocol) is a network protocol that allows for the streaming of video and audio data over a network. It is commonly used for IP surveillance cameras, as well as for streaming media content. The protocol allows for control of the stream, including pausing, rewinding, and fast-forwarding, as well as the ability to change the resolution and quality of the stream. It can be used over both IPv4 and IPv6 networks, and can be carried over a variety of transport protocols, including TCP and UDP.

Uncooled LWIR infrared imaging cameras are the most common type of thermal cameras, as they more affordable than cooled MWIR thermal cameras. In addition to the upfront costs of the camera being more affordable, uncooled thermal cameras require no cooling, which means no regular cryocooler maintenance or replacement as is the case with MWIR cooled thermal cameras.
An f‑number (ƒ/#) or f‑stop refers to the ratio of a lens’s focal length to its aperture’s diameter (lens opening vs focal length) and indicates the amount of IR energy (heat) coming through the lens to the infrared sensor. The lower the f-number the larger the aperture diameter, meaning more thermal IR energy is reaching the infrared sensor.

AUDS is an acronym for Anti-UAV Defence System and refers to a specific product that was released in 2015 by Blighter Surveillance Systems, Chess Dynamics, and Enterprise Control Systems. As it was once of the first commercially available C-UAS (Counter-Unmanned Aircraft System) some incorrectly use it as a generic term for anti-drone rather than a specific product. So AUDS is product that falls under the category C-UAS and Anti Drone, but other solutions should not be referred to as AUDS.