NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Leg56. Chart vs formulas
From: Andr?s Ruiz
Date: 1999 Jul 16, 05:15 EDT
From: Andr?s Ruiz
Date: 1999 Jul 16, 05:15 EDT
In coastal navigation I use the charts for navigation, but when the distance is outside of the chart, for me is easier to use a calculator with trigonometric functions in order to obtain the DR position, or to find the rhumb to a point. I've compared the Mid-Latitude Sailing, the RhumbLine, and the Great Circle Sailing of the point 2) of the Leg 56, and here are the results. The distance is a great one, because of this the best method is to divide the GC track in small legs, and sail between them by a rhumbline, from a waypoint to another. Lat1 Lon1 R d Lat2 Lon2 LatitudMed R, d ? -42.6633 -98.8583 124.3904 1487.5287 -56.6667 -67.25 Loxodromica R, d ? -42.6633 -98.8583 124.5705 1480.7388 -56.6667 -67.25 Ortodromica R, d ? -42.6633 -98.8583 135.9026 1466.8856 -56.6667 -67.25 Ortodromica WayPoint -42.6633 -98.8583 135.9026 506.8132 -48.4098 -90 Ortodromica WayPoint -48.4098 -90 129.5663 245.2815 -50.9095 -85 Ortodromica WayPoint -50.9095 -85 125.7533 222.4828 -52.9731 -80 Ortodromica WayPoint -52.9731 -80 121.8148 204.0477 -54.6645 -75 Ortodromica WayPoint -54.6645 -75 117.7777 189.2925 -56.0348 -70 Ortodromica WayPoint -56.0348 -70 113.6634 177.6471 -57.1245 -65 Ortodromica WayPoint -57.1245 -65 289.4892 78.6791 -56.6667 -67.25 If you want, in the address below, you can find the algorithm for mercator sailing and rhumbLines. The titles are in Spanish, but the algorithm are mathematics, universal language. http://www.geocities.com/CapeCanaveral/Runway/3568/index.html [Navigation] [Mercator sailing] I translate some words for anyone interested: Rumbo y distancia Course and distance Posicion. La estima Dead reckoning Loxodromica Loxodromic or rhumbLines Partes meridionales Meridional parts I don't know what is the difference between mercator sailing and rhumbline, for me is the same ?? Andr?s Ruiz e-mail: aruiz@XXX.XXX http://www.geocities.com/CapeCanaveral/Runway/3568/index.html