RESEARCH AND DEVELOPMENT, 1975 



Development of methods to tag icebergs for 

 reidentification and drift analysis using various 

 dye combinations continued with marginal suc- 

 cess during the 1975 season. The natural insta- 

 bility of icebergs caused the dyes to be immersed 

 and washed off. Calving would eventually result 

 in several pieces of the original iceberg, dyed 

 and/or clean, drifting off which would hinder 

 identification. 



An air deployed metal dart (penetrometer) 

 was tested using the patrol aircraft and CGC 

 SHERMAN as the surface observer. The 

 penetrometer was thrown from the rear of the 

 aircraft and would imbed itself in the face of the 

 iceberg. A tag line with a wooden block was 

 attached to the penetrometer. The surface vessel 

 could then approach and replace the block with a 

 transmitter for later location and identification 

 using a direction finder. Further development 

 of a reliable air deployable transponder would 

 eliminate the need for a surface vessel and allow 

 aircraft to tag icebergs on regular patrols. 



Integrating current drogues were used for the 

 first time by Ice Patrol. These drogues provided 

 current data for iceberg drift experiments being 

 conducted from CGC EVERGREEN. Half 

 hourly wind data from shipboard anemometers 

 and iceberg drifts observed visually or through 

 ship's radar were recorded during these experi- 

 ments. Empirical analysis of these data provided 

 for increased understanding of the reaction of 

 icebergs to the two primary forces responsible 

 for their drift. 



In April a NASA Lewis Research Center 

 owned APS-94C Side Looking Airborne Radar 

 (SLAR) was tested using the regular Ice Patrol 

 aircraft to obtain simultaneous ground truth data 

 for evaluation. Initial results indicated an out- 

 standing target detection capability with very 

 little target identification improvement over 

 previous CG Research and Development Center 

 findings. Follow on development of improved 

 imagery interpretation is planned. 



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