A subspace infrared algorithm is a process for analyzing subspace infrared telemetry, received from spatial phenomena such as stellar clusters. The algorithm consists of four analytical aspects, which can be regarded as four smaller algorithms. Their sequence is:

1. Zeta particle derivation
2. Gamma wave frequency
3. Ion distribution
4. Flow rate of positrons

Starfleet officers have a mnemonic device for remembering the sequence: Z.G.I.F., "Zero-G Is Fun".

Tal Celes of the USS Voyager was assigned a level-3 sensor analysis of a class T cluster in 2376, involving a subspace infrared analysis. However, she had to seek William Telfer's assistance to perform it. (VOY: "Good Shepherd")