By Gordon Barnes

1. ACGS first entered SEA as AST-1 on 25 April 1966. Stayed until 9 June 1966.

2. Went back in July 1967 as AST-3 and closed out operations in April 1970-whole time in TDY status.

3. Assigned seven primary tasks:

   a. Electronic Geodetic Surveying(HIRAN)

   b. Horizontally Controlled Photography(HCP)

   c. Secondary Control-Point Photography(SCP)

   d. LORAN Calibration Photography

   e. Cartographic Photography

   f. Terrain Profile Recording(TPR)

   g. Satellite Triangulation

4. Specific Projects:

   a. Razor Clam (AF 66-81): Positioned 13 points in Vietnam and off the coast. Also flew seven HCP lines, 13 trilat lines, and 1250 linear miles of HCP.

   b. Combat Look (AF 67-46): Flew LORAN calibration and cartographic photography in and near the DMZ and in a classified area. 1745 linear miles.

   c. Combat Sky Spot (AF 68-11): Highly classified short term project involving both aerial and ground survey efforts. Six trilat lines, one astro position and azimuth.

   d. AF 68-14: Positioning of four islands off the coast of RVN. Four SCPs.

   e. Wayside (AF 68-15): Solid, simultaneous HCP/LORAN/TPR mapping coverage of South Vietnam. 14,169 linear miles, 22 trilat lines.

   AF 68-15A: LORAN calibration photography of a classified area. 824 linear miles.

   AF 68-15B: Cartographic photo along Laos and Cambodian borders for rapid support of combat operations. 1000 linear miles.

   f. Satellite Triangulation--used to tie Vietnam and Thailand datums and establish azimuth between two Vietnam HIRAN stations for azimuth control. Two stations in Thailand, two in Vietnam, one azimuth.

   g. Combat Iron (AF 69-10): HCP in Thailand to obtain coverage of areas of interest and test suitability of previous cartographic photography to update maps. 880 linear miles.

   h. Commando Hunt (AF69-10A): SCPs and simultaneous HCP/TPR/LORAN photography in a classified area. 11 SCPs, 1,686 linear miles.

   i. AF 69-10B: A LORAN variation test in Thailand to establish LORAN variation by system. Four points.

   j. Project Honer: Trilateration to extend control in Vietnam for use by Army artillery units. 22 stations. 79 trilat lines.

   k. AF 69-14: HIRAN/LORAN correlation tests to determine the horizontal, vertical, and diurnal variation of LORAN in Vietnam. Ten equivalent SCPs and 480 linear miles of HCP/LORAN.

l. AF 69-36: HCP/LORAN of a special interest area of Vietnam. 3,550 linear miles.

   m. Combat Queen (AF 70-25): Trilateration to tie Vietnam to Thailand control and a small area of LORAN/cartographic photography accomplished before activities were terminated in SEA. 19 equivalent trilateration lines, 403 linear miles of LORAN/cartographic photography.

   n. Many MACV and 7th AF projects. Mostly pinpoint photography of bases, airfields, helicopter pads, and cantonment areas and also mapping photography of areas of great military concentration; e.g., Saigon, Bien Hoa, Tuy Hoa, and Nha Trang. TOTALS: 3,544 linear miles, 413 pinpoint photos, one SCP.

   o. AF 69-1, 70-9 and 68-15 (ground survey efforts). Ground surveys to position many nav aids in Thailand. Still in progress in June 1970. Also provided control on all major Thai airfields. In addition four stations surveyed in Vietnam for Army under 68-15.

5. Significant heroic achievements:

   a. Ground station at Ha Tien came under fire both while being reconned and while operational.

   b. During AF 67-46 and 69-10A, ACGS flew unarmed aircraft on straight regular flight lines at a constant altitude well within range of enemy anti-aircraft artillery and SAMS.

   c. During our support of 68-11, ACGS both flew and had ground station and ground survey personnel deep within an hostile area.

6. Summary of Geodetic Achievements:

   a. 22,015 linear miles of HIRAN Controlled Photography.

   b. 22,857 linear miles of LORAN Calibration Photography.

   c. 7,516 linear miles of Cartographic Photography.

   d. 16,735 linear miles of vertically controlled photography using the Terrain Profile Recorder (TPR).

   e. 33 Secondary Control Points (SCP) and 139 trilateration lines used to geodetically position points of interest.

   f. Miscellaneous:

   (1) One astronomic latitude, longitude, and azimuth.

   (2) Four satellite triangulation stations and one azimuth determination using these stations.

   (3) Four points to test LORAN variation by system.

   (4) Three points to determine vertical and diurnal variation of LORAN.

   (5) 413 pinpoint photos of bases, airfields, helicopter pads, cantonment areas, etc.

   (6) Four sites geodetically positioned by ground surveys in Vietnam and many nav aids positioned by ground survey in Thailand.