Radar Picket Duty

Click Here to see a map of the Radar Picket Stations around Okinawa.

Distant radar pickets were stationed between 40 and 70 miles from the transport area in the direction of the approach of enemy aircraft from the Japanese Island chain, China bases, and Formosa. Close radar pickets were stationed 20 to 25 miles from the transport area. In addition, stations in the outer and inner anti-submarine screen were designated as radar picket stations. Their special duty consisted of detecting, tracking, and reporting on aircraft in the vicinity of the transport area.

The function of the distant radar pickets was to give early warning of enemy air raids and surface craft, and to perform the duties of fighter direction. Specially equipped fighter-director destroyers with fighter director teams embarked were used as fighter director ships. These fighter-director destroyers controlled such units of the CAP as were assigned them by the central fighter-director unit embarked in the ELDORADO or other headquarters ship. Initially a radar picket group was composed of one FD (fighter-director) destroyer and two LCS supports. Each LCS was stationed one thrid the distance to an adjacent radar picket station to increase the probability of detection of low-flying planes and barge or other surface movement along the island chain. In case of attack, the supports closed the radar picket for mutual protection. This formation was later changed, and the LCS's were stationed with the picket as close supports.

The vital importance of maintaining radar picket groups on station can be attested by the fact that the bulk of the defense of the Okinawa amphibious operation evolved around the raid reporting and fighter direction exercised by these exposed fighter-director ships and their supporting elements. It became apparent early in the operation that the brunt of the enemy air attacks would be absorbed by the radar pickets and units of the outer A/S screen, therefore it was considered necessary to increase the number of units on each radar picket station and prove the number of occupied radar picket stations was seriously examined, but the number could not be reduced until after shore based radar based radar stations were in operation.

During the first days of the operation there were insufficient destroyers available to assign more than one destroyer to each picket station. This was occasioned by other required employment such as (1) the necessity of assigning destroyers to screen transport groups, and covering groups in night retirement; (2) Assignment of destroyers to task groups in awaiting areas; (3) the necessity of having units available to meet emergencies. However, the strength of the radar picket stations was increased by assigning all available LCS, LSM(R), and PGM types as close supports. Later when night retirement was discontinued and groups returned from awaiting areas, additional destroyers were assigned as radar picket supports. Beginning 10 April it was possible to assign two destroyers and four small support craft to the more exposed radar picket stations. Continued damage to units prevented increasing the strength further until reinforcements arrived from other areas and the number of picket stations was reduced. Finally on 19 May it became possible to maintain at least three destroyers and four LCS's on each of the five occupied stations.

Destroyer-escorts and similar type were considered as picket supports. Their inadequate anti-aircraft armament precluded exposing them to the vicious air attacks experienced on radar picket stations. None of the destroyer-escorts with the increased armament of two 5-inch, ten 40mm, and ten 20 mm. guns were at the objective.

Continued efforts were made to obtain a protective CAP of from four to six planes for each picket station. This special CAP was to be employed solely for local picket protection, reporting directly to the radar picket on a special frequency. It was entirely separate from the regular CAP. Sufficient planes were not available at the objective to supply the desired, protective CAP, but commencing 14 April the TAF (Tactical Air Force) was able to maintain a two-plane protective CAP over three picket stations.

In the early stages Radar Picket Stations 1, 2, 3, 4, 7, 10, 12, and 14 were filled, with number 9 later when more warning was thought necessary against low-flying planes approaching Kerama Retto from southwest. On 16 May, with the completion of shore-based radar installations in Hedo Sake and Ie Shima, the number of occupied radar picket stations was reduced to five (Stations 5, 7, 9, 15, and 16.)

Due to damage to fighter-director ships it was necessary to continuously equip additional ships with fighter-director radio and associated equipment and in some ships, not so equipped, with suitable visual fighter-direction stations.

A number of formations were used in the course of the operation. The typical normal cruising formation used with a group of three or more destroyers and four LCS's under the tactical command of a squadron or division commander consisted of a destroyer unit concentrated in an anti-aircraft circular formation with ships equally spaced, distance between ships 1,000 yards, and an LCS unit similarly disposed, with distance between ships 500 yards or less. The LCS unit commander would patrol along a track designated by the officer in tactical command of the picket group. The destroyer unit would patrol as directed...keeping within 3000 yards of the LCS unit.