The North Australian Observation Unit was formed in early 1942 to patrol remote parts of Northern Australia. Part of the O'Donahoo Collection. See Cat 1992 for details of service for Arthur Raymond O'Donahoo, VX135349.1. & 2. Felt patch with mustard-yellow coloured lozenge shape next to a dark green lozenge shape. Grey/Khaki backing. 2. Has grey backing and is a smaller version of 1.o'donahoo collection, arthur raymond o'donahoo, northern australia observation unit, naou, ww2, colour patch

This is a set of 26 photographs of Royal Australian Survey Corps (RA Svy) personnel from Central Comd Fd Svy Unit (Adelaide) on Aerodist survey operation - Project C4 in Eastern Arnhem Land, Northern Territory in 1967 (photos .4P to .26P) and in Western Arnhem Land, Northern Territory in 1968 (photos .1P to .3P). Photos of personnel were taken either at the operations base at Numbulwar or the main base at Gove (Nhulunbuy). RA Svy conducted nineteen Aerodist operations for 12 years from 1964 to 1975. Aerodist MRC2 was a tellurometer-based system adapted for aircraft to accurately measure distances between non-intervisible ground survey stations, using the aircraft as an intermediate station. Lower order geodetic results could be achieved by survey network trilateration. The measured distances between stations formed survey networks from which each station’s latitude and longitude was computed. Aerodist MRC2 was RA Svy’s major horizontal control survey tool for mainly medium scale topographic mapping (scale 1:100,000 Class A being spatially accurate to within 50 metres) in PNG, northern NT, north-west WA, Kalimantan Barat (West) Indonesia, Sumatra Indonesia, Gulf of Carpentaria and Cape York, QLD. In 1967, the Aerodist MRC2 Master equipment was installed in the aircraft featured in this set of photos, Executive Air Services’ (Essendon VIC) Grand Aero Commander VH-EXX. It was the same aircraft type and company contracted to Division of National Mapping for Aerodist MRC2 surveys. From July to October 1967 the aircraft was attached to Central Comd Fd Svy Unit (Adelaide - Major Don Ridge) on Project C4 eastern-Arnhem Land NT, where 317 Aerodist lines measuring 17,300 line miles were successfully completed. This was the most productive Aerodist project thus far. The most common helicopter used by RA Svy up to 1972 was the civilian Bell 47G-2 and the Sioux Light Observation Helicopters (LOH), the Australian Army’s equivalent featured in this photo set. These light observation helicopters had a limiting load carrying capacity of up to about 500 pounds. By comparison, one Aerodist team including two people weighed up to 1,500 pounds. In 1968, after completion of the Kimberley Aerodist Operation project, the Aerodist system in VH-EXX was immediately deployed to western-Arnhem Land NT for Central Comd Fd Svy Unit (Adelaide - Major Don Ridge) to complete the mapping control across northern NT from mid-July to October. The Aerodist MRC2 Remote antenna seen in Photos .24P to .26P is mounted on a 20 foot pole tower. The antenna direction was controlled by wires/ropes to the two arms under the dish at right angles. The antenna elevation could be changed to the vertical for aircraft height checks as seen in photo .25P. Source: Royal Australian Survey Corps – Aerodist Years 1964-1975 by Peter Jensen. Refer to Item 6449.30P for more photos taken during these Aerodist survey operations.This is a set of 26 photographs of Royal Australian Survey Corps (RA Svy) personnel on Aerodist survey operations in Eastern Arnhem Land, Northern Territory in 1967 and Western Arnhem Land, Northern Territory in 1968. The photographs are on 35mm negative film and scanned at 96 dpi. They are part of the Army Survey Regiment’s Collection. .1) to .2) – Photo, black & white, 1968, unidentified soldier with an opened can of food, possibly bully beef. .3) – Photo, black & white, 15 Aug 1968, aerial view of terrain taken from a helicopter in vicinity of MILINGIMBI SIERRA. .4) – Photo, black & white, 1967, aerial view of an island taken from a helicopter. .5) & .6) – Photo, black & white, 1967, unidentified soldier driving a Haflinger 4x4 Light utility vehicle with trailer. .7) – Photo, black & white, 1967, unidentified surveyors taking vertical measurements with a leveling instrument and staff. .8) – Photo, black & white, 1967, Australian Army Sioux Light Observation Helicopter (LOH) with float removed. .9) to .11) – Photo, black & white, 1967, Australian Army Sioux Light Observation Helicopter (LOH) with floats. .12) – Photo, black & white, 1967, civilian Bell 47G-2 helicopter (Australian Army Sioux LOH equivalent) refuelled. .13) – Photo, black & white, 1967, survey station on coastline surrounded by white plastic aerial photographic identification panels lined with rocks. .14) & .15) – Photo, black & white, 1967, soldier (possibly a signaller from RA Sigs) operating a radio. .16) – Photo, black & white, 1967, Central Comd Fd Svy Unit Operations Section tent, Main Base Gove (Nhulunbuy) L to R: SPR Harry Dunn, WO1 Pat Wood BEM. .17) – Photo, black & white, 1967, Central Comd Fd Svy Unit Operations Section tent, Main Base Gove (Nhulunbuy) L to R: unidentified, WO1 Pat Wood BEM. .18) – Photo, black & white, 1967, Central Comd Fd Svy Unit Operations Section, Main Base Gove (Nhulunbuy), unidentified Australian Army Catering Corps cook preparing meals. .19) – Photo, black & white, 1967, Central Comd Fd Svy Unit Operations Section, Main Base Gove (Nhulunbuy) mess tent in readiness for meals. .20) – Photo, black & white, 1967, Bank of batteries in transit boxes undergoing recharging using generators. .21) – Photo, black & white, 1967, A topographic survey identification plaque set in a concrete block being weighed using a set of scales hanging from slaughtering gallows. .22) – Photo, black & white, 1967, CPL (Geoff or Gary) Larkin operating the remote Aerodist MRC2 ground instrument at Veronica Island, located north of Nhulunbuy. .23) – Photo, black & white, 1967, L to R: CPL (Geoff or Gary) Larkin with unidentified surveyor operate the remote Aerodist MRC2 ground instrument at Venica Island, located north of Nhulunbuy. .24) & .25 – Photo, black & white, 1967, The Aerodist MRC2 Remote antenna. .26) – Photo, black & white, 1967, The Aerodist MRC2 Remote antenna.The following photos are annotated in black ink on edge of film negative: .3P – ’15 Aug ’68, 2000’, 1-C18 ’68 MILINGIMBI SIERRA’ .4P – ’U462’ .8P – ‘1-C3/67 Float Removed’ .13P – ‘U477 10-C3/67 .20P - ‘2-C3/67 Bank of Chargers’ .21P - ‘3-C3/67 Gallows & Scales’ .22P - ‘0462 VERONICA ISLAND NT, CPL Larkin’ .23P - ‘0462 VERONICA ISLAND NT’ .24P - ‘4-C3/67 20’ Aerodist Tower’ .25P - ‘5-C3/67 20’ Aerodist Tower’ .26P - ‘6-C3/67 20’ Aerodist Tower’royal australian survey corps, rasvy, army survey regiment, army svy regt, fortuna, asr, aerodist, surveying, central comd fd svy unit