Why we use long by Chron ?

There are various reasons, i wanna tell the major ones with a little clarity, 

1.    

In morning sun's bearing is easterly, and we know position line is perpendicular to azimuth, so PL by long by chron using sun in morning will nearly be north and south and second pl at merpass will be east west...so the cut will be perpendicular and fix will be very accurate. 

2.

Secondly, in morning sun's altitude is increasing very rapidly and we know in the intercept formula we compare TZD and CZD to get the intercept, and TZD is complementary to T.ALT so if we make any error in the observation of altitude like time we noted something else and the observation we took is little early or late, it will result in a noticeable error, as we know 1 minute equals 1 MILE

                                              Whereas, in LONG BY CHRON we calculate angle P and in the formula we can clearly note that the T.ALT is the function in NUMERATOR so it will hardly make any different, if there is a slight error.

3.

Third is that using LONG by chron, we can find the position of FIX without any plotting, only by the help of calculations. And for that you need to go a little in deep, there is a procedure which involves D'LONG= C CORRECTION × D'LAT

 

These three reasons are enough to support that why....