Automatic transponder

US4042926A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Roy E. Anderson · New Orleans, US
• Alex Brisken · Ballston Lake, US

Key dates

• Filing date: Mar 27, 1975
• Grant date: Aug 16, 1977
• Expiry date: Mar 27, 1995

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S13/767
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and apparatus for the automatic, remote measurement of the internal delay time of a transponder at the time of operation is provided. A small portion of the transmitted signal of the transponder is converted to the receive signal frequency of the transponder and supplied to the input of the transponder. The elapsed time between the receive signal locally generated and the receive signal causing the transmission of the transmitted signal is measured, said time being representative of or equal to the internal delay time of the transponder at the time of operation.