Method and apparatus to simultaneously measure emissivities and thermodynamic temperatures of remote objects

Apparatus for measurement of the thermodynamic temperature of a radiating object comprising

• a light source means of given wavelength for reflecting a beam of light off the object at a given angle,
• means for interrupting said beam of light,
• detector means for receiving radiation from said object comprising both
• the self-emitted radiation from the object when the light is off in order to determine the brightness temperature of the object and
• combined reflected and transmitted radiation from the object when the light source means is on, in order to determine the emissivity of the object.
• said detector means comprising means for amplitude splitting of the received radiation into two component beams,
• means for dividing each of the two component beams into two beams each of polar components, and
• means for measuring the intensities of the four resulting components, said intensities being related to the four Strokes vectors of the received radiation, and computing means for computing the brightness temperature and emissivity of the object and for combining said brightness temperature and said emissivity to determine the thermodynamic temperature of the object.

Method for non-contact measurement of the thermodynamic temperature of a remote object, said method comprising the steps of

• reflecting a beam of light of known frequency and polarization off the object at a given angle,
• arranging a detector to receive radiation of said known frequency and at said given angle,
• amplitude splitting of the radiation received by said detector followed by division of the split beam into four polarization components,
• alternatively interrupting said beam of light while measuring the intensities of said four components to obtain four values for two states wherein one state comprises both transmitted and reflected radiation and the other state is self-emitted radiation;
• and
• irrespective of order, calculating the brightness temperature of the object from said self-emitted radiation intensities and emissivity of the object from said transmitted and reflected intensities, and combining these to determine the thermodynamic temperature of the object.