operate in potential iceberg areas. These forms required the maximum 

 range of detection and the physical measurements of height and length 

 together with a photograph or sketch of the aspect seen by the radar at 

 the recorded range. Of the 1!)1 reports submitted 138 were sufficiently 

 complete for use in this investigation. In addition, 24 observations from 

 L945 were utilized resulting in a total of L52 iceberg observations included 

 in this discussion. 



The 



Location of Targets 

 locations of the ice targets studied this year are shown in figure 22. 



Nineteen icebergs, included in this study, which were investigated by the 

 icebreaker, USCGC Westwind, north of 70° North latitude are not shown. 

 It is important to note that most of the ice targets were in the Grand 

 Banks region or the North Atlantic shipping lanes. The controlled quanti- 

 tative studies made by the Ice Patrol cutters are distinguished by the 

 solid circles. These observations were made from March to October I!).")!). 



Instrumentation 



The X-band Radar, model AX SPS-23, on the Coast Guard cutlers 

 Acushnet and Androscoggin was used for the bulk of the controlled re- 

 flectivity measurements and anticlutter device evaluation. The measure- 

 ments of overall radar performance and the measurements of reflected 

 power were made by use of the Radar Test set, type TS-147DTT. 

 This portable, microwave signal generator provided measurements of 

 power output, transmitter and receiver frequency, and echo signal 

 st length of reflected power from the radar targets. The reflected power 

 measurements were made by matching an internally generated signal of 

 known adjustable power with the target signal on an "A" scan. A block 

 diagram of the equipment set up is shown in figure 23. The accuracy of 



FuaRE 23. — Block diagram showing the linkage of test equipmenl to radar compo- 

 nents (test set RF tri^K'Tcd). 



53 



