It is part of the Greek military on the island Kos. Here is more information, as given on zone-interdite.

Kos Isl. garrison. 80th National Guard Command
80ή ΑΔΤΕ is under ASDEN command and responsible for the Kos region defense.
Unit organisation:
HQ Coy (ΛΣΤ/80 ΑΔΤΕ)
– 80th NG Armored Battalion (80 ΕΑΡΜΕΘ) and Armored Reconnaissance Battalion (80 ΕΑNΕΘ)
– 282nd and 543th NG Battalions (282/543 M/KTE) Mechanized
– 295th and 588th NG Battalions (295/588 ΤΕ)
– 80th NG Artillery (80 MΕΘ), Anti Aircraft Artillery (80 MΕAΠ), Medical (80 ΤΥΕΘ) and Support Battalions (80 ΤΥΠΕΘ)
– 80th Anti Tank (80 ΛAT), NG Anti Τank (80 ΛΑΤΕΘ), Engineers (80 ΛΜΧ) and Signal Companies (80 ΛΔΒΕΘ)

The air force EW radar located at grid 36° 51′ 24″ N 27° 18′ 51″ E