STANDARD LORAN 



{A Long Range Aid fo Navigational System) 



INTRODUCTION 



The Loran system is a modern electronic aid to navigation by means of 

 which navigators on or over the ocean can determine their position accurately 

 and quickly, day or night, and under practically any condition of weather and 

 sea. The name "Loran" was derived from the words "LOng RAnge Naviga- 

 tion," which describe in general terms the system's relative utility when com- 

 pared to ranges of other electronic navigational aids. The effective range of 

 Loran is as great as 1,400 nautical miles at night and 750 miles during the day 

 (fig. 1-1) . The accuracy obtained is comparable to that which may normally 

 be expected from good celestial observations. Even though such precision 

 is attained, the determination of position by Loran requires but 2 to 3 minutes' 

 time. 



The navigator can think of Loran merely as a method of determining 



DAY AND NIGHT COVERAGE AREA 



n$:n:$:^j night coverage area 



Figure 1-1. — Typical day and night Loran coverage area. 



