Hudson VH-AGS Aerodist antenna locations.

The top view shows the original configuration of 1 topside and 2 on the belly.
The bottom view shows the final configuration of 1 on the belly and 1 under each wing tip.
(Click on the image for a larger view)

The following description of Aerodist appears on page 2 of the August 1965 issue of "Australian Aerial Survey Review".

"Aerodist represents an example of Adastra's co-operation with the National Defence Services.

This instrument is made in South Africa by the producers of the widely-used tellurometer system, which is operated by microwave, and used for ground measurement of geodetic distances.

As used in Adastra aircraft, Aerodist is designed for simultaneous measurement, during flight, to three ground stations, known respectively as Red, White and Blue.

Its function is long-range extension of horizontal control, and aircraft positioning in aerial survey.

The immediate effectiveness of Aerodist was seen in New Guinea when Adastra began to fly an extensive project on behalf of the Australian Army Survey Corps.

First, Army land parties established ground stations, the most onerous part of the operation.

Survey Corps men were landed by helicopter in small clearings with equipment and supplies in jungle country.

In one case, Army technicians found themselves working among the clouds, on the brink of a 2,000 feet drop.

Speed of Aerodist survey resulted in as much progress being made in an hour as would have been achieved in six months by land parties using conventional methods.

Aerodist gives accurate long-range extension of horizontal control in three ways.

These are:
[1] distance measurement between ground stations, using the aircraft as an intermediate station (line-crossing technique)
[2] fixing an unknown ground station from two known ground stations using an aircraft and continuous trilateration
[3] fixing two unknown ground stations by the foregoing means.

Aerodist accurately positions an aircraft in flight, continuously or at an instant of camera exposure, and also determines altitudes.

In the Adastra aircraft, these facts were obtained by obtaining a fix in space as function of three slant distances, using the Aerodist three channel system, and by using two channels to measure slant distances while the third channel gave direct height measurement from a ground station established at a known height, the ground station antenna being set vertically."

The three channels of the Aerodist system required three separate antennae. The original configuration had one antenna on top of the fuselage and two on the belly. (photos A and B). This was subsequently changed to one on the belly and one under each wing tip. (photos C, D & F). As will be seen from these photographs, the ground clearance for the (non-retractable) aft belly antenna was minimal.

By late April 1965, VH-AGS was being operated without any Aerodist antennae, although the aircraft retained the mounting for the upper fuselage location (photo G). It is believed that VH-AGS was the only Adastra Hudson to carry the Aerodist installation.


PHOTO A: VH-AGS in the original Aerodist configuration outside Hangar 13 at Mascot circa 1963/64. The forward belly antenna is partially obscured. Photo by Ken Watson.

PHOTO B: This undated photo supplied by Kevin Pavlich shows VH-AGS in the original Aerodist configuration with one antenna on the top of the fuselage aft of the D.F. loop fairing and another two on the belly. It appears that the aft belly antenna has been removed from its mount.

PHOTO C: Photographed by Dave Aitchison at Mount Hagen in 1965, VH-AGS carries the final Aerodist fit. Note the minimal ground clearance of the belly antenna!

PHOTO D: Photographed by Dave Aitchison at Mount Hagen in 1965, VH-AGS carries the final Aerodist fit. Note the minimal ground clearance of the belly antenna!

PHOTO E: Keith Cooper walking through the Mount Hagen camp in 1965. The camp was constructed by the Army with the hut on the right being allocated to the Adastra crew. Photographed by Dave Aitchison.

PHOTO F: VH-AGS in the final Aerodist configuration touching down at an unknown location, possibly Albury. Photographed by Dave Aitchison

PHOTO G: Photographed at Brisbane on 29th April 1965 by Ron Cuskelly, VH-AGS retains the mounting for its topside Aerodist antenna. The aircraft did not carry any Aerodist antennae at this time.



Issue Date Remarks
4 16NOV12
Completely revised the locations of the Aerodist antennae based on this image supplied by Ken Watson.
3 12JAN04 -