PHASED ARRAY IMAGING IN PARTIALLY COHERENT LIGHT

WE PROPOSE TO DEVELOP A MATHEMATICAL MODEL AND ASSOCIATED NUMERICAL CODE WHICH WILL PERMIT DETERMINATION OF THE IMAGING PROPERTIES OF A PHASED-ARRAY TELESCOPE IN THE PRESENCE OF PARTIALLY-COHERENT LIGHT. THIS FORMULATION WILL INCLUDE COHERENCE EFFECTS INTRODUCED BY LONG PROPAGATION PATHS AND THE EFFECT OF COHERENCE LOSS THAT OCCURS AS A RESULT OF ATMOSPHERIC TURBULENCE. SIMPLIFIED EXPRESSIONS FOR THE AMPLITUDE IMPULSE RESPONSE OF SUCH TELESCOPES WILL BE DEVELOPED IN TERMS OF THE FREESPACE GREEN'S FUNCTION AND THE APERTURE PHASE SHIFTS. TO ILLUSTRATE THE DEVELOPED THEORY, THE IMAGE OF A RECTANGULAR SOURCE WILL BE COMPUTED WHEN THE RADIATION EMITTED BY THE SOURCE IS PARTIALLY COHERENT. FINALLY, WE SHALL SHOW HOW THE THEORY CAN BE GENERALIZED TO INCLUDE FOURTH-ORDER COHERENCE EFFECTS, AND THUS TO ENABLE US TO CALCULATE THE STATISTICAL FLUCTUATIONS OF THE IMAGE.