From Halopedia, the Halo wiki
Augur arrays are a detection technology employed by the Covenant. They are often employed on the various cruisers of the empire and its remnants, including the Zanar-pattern light cruiser and the various models of CCS-class battlecruiser.
Augurs can be installed on a ship to assist with targeting for various weapon systems including pulse lasers and plasma beams. In the case of the Zanar-pattern cruiser, two such arrays are installed to assist the ship's Pok-pattern lasers to target dozens of targets in rapid succession. They could also be used in noncombat roles, such as divining and unlocking holy secrets from Forerunner artifacts. The battlecruiser Undiminished Entelechy boasted multiple augurs which, working from the ship's control center, attempted to learn the secrets of Installation 04 upon its discovery.
An augur, or auspex, was a priest in Ancient Rome charged with studying the movement of birds as a means of divination. Given its naming, the augur array may have some in-universe relation to the auspex array also used on Forerunner and Covenant warships.
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