OCEAN ELECTRONIC NAVIGATIONAL AIDS 



35 



Figure 3-1. — Cluster of Kadar corner reflectors mounted on standard lighted buoy. 



nun buoys. It is quite possible that the reflector mounting arrangement 

 shown in figure 3-1 will be replaced. Future design will incorporate the 

 corner refiectors in the buoy light tower proper, just below the light as illus- 

 trated in figure 3-2a. Corner refiectors of the future will be constructed 

 of steel instead of aluminum to assure maximum ruggedness. 



Figure 3-3 shows a Radar photo taken during reflector test runs in Balti- 

 more Harbor. Each circular range line on the scope indicates one mile. 

 The vessel was approaching the end of the marked channel. Reflector buoy 

 No. IC is located at 176°, 4.1 miles (almost split by the bearing cursor), at 

 the southern end of the marked channel. Here the Radar return from the 

 reflector buoy can be seen to be nearly as strong as that from the tug and 

 tow which is about one-half mile SSE of the reflector. The very large "pip" 

 located at 181°, 3.4 miles is Baltimore Light, a large structure. Note that the 

 line of buoys extending 335° from the center of the scope steadily decreases 

 in intensity until they cannot be seen past 2.2 miles even though these are 

 the same size buoys as those equipped with reflectors. There are two buoys 

 showing up at 178°, 2.8 miles; but during actual observation of the Radar 

 scope these "pips" were unstable and not continuously bright at this dis- 

 tance, whereas the reflector showed bright at all times. Another reflector 

 buoy. No. 3B, is located at 060°, 3.7 miles, with no other buoys in the vicinity 

 for comparison. In actual use the stationary buoys are readily distinguished 

 from moving ships on the Radar scope. In addition coordination of Radar 

 information with that of the charts would help to identify the buoys. 



MICROWAVE BEACONS 



Progressing from the Radar reflector, the simplest of all forms which the 

 Radar beacon may take, the next step for marine use was the development 

 of a powered beacon known as the "Ramark." This Radar beacon is essen- 



