RADIOMETRY SYSTEM

• US 3,599,211 A
• Filed: 12/16/1968
• Issued: 08/10/1971
• Est. Priority Date: 12/16/1968
• Status: Expired due to Term

• Current Assignee: Mardon Austin
• Original Assignee: Mardon Austin
• Inventors: MARDON AUSTIN
• Application Number:
  US04/785,063
• Time in Patent Office: 967 Days
• US Class Current: 342/351
• CPC Class Codes: G01K 11/006 using measurement of the effect of a material on microwaves or longer electromagnetic waves, e.g. measuring temperature via microwaves emitted by the object G01K17/003, G01J5/00 take precedence; measuring the effect of a material on X-, gamma- or particle radiation G01K11/30
• CPC Class Codes: G01V 8/005 operating with millimetre waves, e.g. measuring the black losey radiation

Abstract

This disclosure relates to a system for detecting metal in a background of terrain or water. It employs a radiometric receiver with input port means directed toward the area to be examined and responsive to thermal emission in two planes of polarization. The system includes means for displaying or comparing the relative emission temperatures in the two planes as an indication of the presence or absence of metal. Fundamentally, the system supresses false alarms due to water.

Claims

1. In a radiometer system in which signals are derived representing emissivities of a surface with regard to different sensing polarizations, means to minimize the effect of variations in target background emissivity on the signals, comprising:

first means to generate a signal representing the average of the derived signals;

second means to generate a signal representing the difference between the derived signals; and

means to generate a signal representing the quotient of the signals generated by said first and second means.

2. The system of claim 1 and means to generate a signal representing the emissivity of a reference target;

and means to combine the reference signal with the derived signals to provide input for said first and second means.