Large scale far-infrared ( FIR ) observations of the Orion complex at 205 and 138 \mu m are presented with an aim of studying the distribution of cold ( < 25 K ) dust .
The maps in these FIR bands extend over \sim 3600 sq .
arcmin and cover regions around OMC-1 , 2 , 3 in Orion A and NGC 2023 and NGC 2024 in Orion B .
Some limited regions have also been mapped at 57 \mu m. A total of 15 sources in Orion A and 14 in Orion B ( south ) have been identified from our FIR maps .
Dust temperature distribution in both Orion A and Orion B ( south ) have been determined reliably using the maps at 205 & 138 \mu m obtained from simultaneous observations using almost identical beams ( 1 \farcm 6 dia ) .
These temperatures have been used to generate map of \tau _ { 150 } , the optical depth at 150 \mu m , for the Orion B region .
The coldest source detected is in OMC-3 and has a temperature of \sim 15 K. The diffuse FIR emission in the different sub-regions is found to vary between 25 % to 50 % of the total FIR emission from that sub-region .