Over-The-Horizon Radar:

Better Justification Needed for DOD Systems' Expansion

NSIAD-91-61: Published: Jan 16, 1991. Publicly Released: Jan 16, 1991.

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Pursuant to a congressional request, GAO: (1) examined the Department of Defense's (DOD) plans to use the Air Force's Over-the-Horizon Backscatter (OTH-B) radar for counterdrug purposes; and (2) provided information on the cost, design, acquisition and deployment, missions, and interoperability of OTH-B and the Navy's Relocatable Over-the-Horizon Radar (ROTHR) programs.

GAO found that DOD: (1) had conflicting information regarding the OTH-B central system's primary mission, including the shift in the first sector's radar coverage area from the east to the southwest and the transfer of planned funds for fiscal year 1991 from the Air Force's budget to the DOD counterdrug budget; (2) did not adequately justify its planned procurement of the first central system sector for counterdrug purposes, since it did not base the procurement decision on a cost-effectiveness analysis of existing surveillance sensor alternatives; (3) should consider the Navy's ROTHR as an alternative to OTH-B, since it could be less costly and may be able to satisfactorily perform the counterdrug mission; (4) should evaluate the best geographic locations for deploying the over-the-horizon radar and the availability of satisfactory operational test data; and (5) failed to clarify the central system's contribution to the North American Aerospace Defense Command's air defense mission because of changes in its planned use, shifting priorities assigned to individual sectors, and a lack of operational testing of the eastern system, making any further investment in its use for air defense purposes premature.

Matters for Congressional Consideration

  1. Status: Closed - Implemented

    Comments: DOD cancelled plans to procure the central radar system.

    Matter: Congress should consider requiring DOD to clarify the primary purpose of the central radar system. If the primary mission is for the air defense mission, rather than the counterdrug mission, future budget requests for the central system should be justified on that basis, describing what threat the system is expected to detect.

  2. Status: Closed - Not Implemented

    Comments: DOD cancelled plans to procure additional OTH-B sectors.

    Matter: Congress should consider requiring DOD to demonstrate that satisfactory operational test results have been achieved on the east coast radar system before providing funds for any additional OTH-B sectors.


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