The Tellurometer was the first successful microwave electronic distance measurement equipment.

History

The original Tellurometer, known as the Micro-Distancer M/RA 1, was introduced in 1959. It was invented by Dr. Trevor Lloyd Wadley

Trevor Wadley

Trevor Lloyd Wadley, was a South African electrical engineer, best known for his development of the Wadley Loop circuit for greater stability in communications receivers....

 of the Telecommunications Research Laboratory of the South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

n Council for Scientific and Industrial Research

Council for Scientific and Industrial Research

The Council for Scientific and Industrial Research is South Africa's central and premier scientific research and development organisation. It was established by an act of parliament in 1945 and is situated on its own campus in the city of Pretoria...

 (CSIR), also responsible for the Wadley Loop

Wadley Loop

The Wadley Loop circuit was designed by Dr. Trevor Wadley in the 1940s and was first used for a stable Wavemeter.- Overview :In a traditional superheterodyne radio receiver, most oscillator drift and instability occurs in the first frequency converter stage, because it is tunable and operating at a...

 receiver, which allowed precision tuning over wide bands, a task that had previously required switching out multiple crystal

Crystal

A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...

s.

Methodology

The Tellurometer emits an electronic wave: the remote station reradiates the incoming wave in a similar wave of more complex modulation

Modulation

In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

, and the resulting phase shift was a measure of the distance travelled. The results appear on a cathode ray tube

Cathode ray tube

The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...

 with circular sweep. This instrument penetrates haze and mist in daylight or darkness and has a normal range of 30-50 km but can extend up to 70km.

Application

The Tellurometer design yields high accuracy distance measurements over geodetic

Geodesy

Geodesy , also named geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field, in a three-dimensional time-varying space. Geodesists also study geodynamical phenomena such as crustal...

 distances, but it is also useful for second order survey work, especially in areas where the terrain was rough and/or the temperatures extreme.

Examples of remote locations mapped using Tellurometer surveys are Adams Bluff

Adams Bluff

Adams Bluff is a bluff standing north of Peters Peak in the Holyoake Range of the Churchill Mountains. Mapped by the United States Geological Survey from tellurometer surveys and Navy air photos, 1960–62. Named by Advisory Committee on Antarctic Names for Paul L...

, Churchill Mountains

Churchill Mountains

The Churchill Mountains is a mountain range bordering the western side of the Ross Ice Shelf between Byrd Glacier and Nimrod Glacier in Antarctica...

, Cook Mountains

Cook Mountains

The Cook Mountains is a group of mountains bounded by the Mulock and Darwin glaciers in Antarctica. Parts of the group were first viewed from the Ross Ice Shelf by the British National Antarctic Expedition...

, Jacobsen Glacier

Jacobsen Glacier

Jacobsen Glacier is a glacier flowing east-northeast from Mount Reid, in the Holland Range, into the Ross Ice Shelf. Mapped by the United States Geological Survey from Tellurometer surveys and Navy air photos . Named by Advisory Committee on Antarctic Names for H. Jacobsen, Master of the USNS...

, Mount Albright, Mount Predoehl, Mount Summerson, Sherwin Peak and Vogt Peak.

The MRB2 or Hydrodist was a marine version that was used in coastal surveys and calibrating ships using other survey navigation systems.

Commercial exploitation

Plessey

Plessey

The Plessey Company plc was a British-based international electronics, defence and telecommunications company. It originated in 1917, growing and diversifying into electronics. It expanded after the second world war by acquisition of companies and formed overseas companies...

, the British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 electronics company, formed a new subsidiary known as Tellurometer (Pty) Limited in the 1960's to manufacture the product and to develop and sell derivatives. The Company subsequently introduced numerical displays, solid state transmitters, integrated circuits and eventually microprocessor

Microprocessor

A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...

s for the product.