US 4,307,397 A · Method of and apparatus for measuring distance

Abstract

This invention relates to a method and apparatus for determining the distance between two positions utilizing electromagnetic waves (EMW's) and the Tellurometer principle. However, instead of utilizing a separate auxiliary EMW at the remote position for each measuring EMW transmitted from the master position a single auxiliary EMW is generated at the remote position and this single auxiliary EMW is utilized with several measuring EMW's. The measuring EMW's have frequencies that differ from that of the auxiliary EMW by similar amounts. Further, the measuring EMW's have frequencies of suitable values so that pattern frequencies and their phase shifts can be derived directly from some of the measuring EMW's and from the difference between appropriate measuring EMW's. The invention is extended, where a large number of measuring EMW's are needed to provide sufficient pattern frequencies for the degree of accuracy required, by providing a plurality of auxiliary EMW's at suitably different frequencies. All of these auxiliary EMW's are simultaneously generated and transmitted, the appropriate auxiliary EMW for a particular measuring EMW being automatically selected by filtering action at the master and remote positions.

Claims29

Dependent claims

A method of determining the linear separation between a first and a second position, including

generating at the second position an auxiliary electromagnetic wave (EMW) of a constant predetermined frequency;
sequentially generating at the first position a series of at least three measuring EMW's that have frequencies that are suitably different from one another and suitably different from that of the auxiliary EMW;
transmitting the auxiliary EMW, and sequentially each measuring EMW between the two positions;
determining the propagation phase shift of each measuring EMW utilising the auxiliary EMW;
and
processing the phase shifts of the various measuring EMW's to determine the distance between the first and second positions.

3 more elements

An apparatus for determining the linear separation between a first and a second position, including

an auxiliary EMW generating means, locatable at the second position for generating at the second position an auxiliary EMW at a constant predetermined frequency;
a measuring EMW generating means, locatable at the first position for sequentially generating at the first position a series of at least three measuring EMW's that have frequencies that are suitably different from one another and suitably different from that of the auxiliary EMW;
a transmitting means for transmitting the auxiliary EMW, and sequentially each measuring EMW between the two positions;
and
a phase shift determining means for determining the propagation phase shift of each measuring EMW utilising the auxiliary EMW.

2 more elements

Dependencies are inferred from the claim text.

Method of and apparatus for measuring distance

Life of this patent

Method of and apparatus for measuring distance

Life of this patent

Abstract

Claims29