NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Mileage of rhumb line compared to mileage of great circle
From: Dave Walden
Date: 2011 Jun 5, 07:28 -0700
From: Dave Walden
Date: 2011 Jun 5, 07:28 -0700
The "MY" refered to below is the "Meridional Parts" function. Table 5 in my 1962 Bowditch, Table 3 in 1918, and Table VI (Latitudes Croissantes in French) in Friocourt, and in many other collections of tables.
>>That is trickier, but still not a rocket science.
>>tan(TC)=(lon2-lon1)/(MY(lat2)-MY(lat1))
>>where MY(lat) is Y coordinate in mercator projection
>>MY(lat)=ln(tan(45+lat/2))
>>nsg
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