Sight Reduction Methods
This Learning Guide, written for self-instruction, teaches five methods of reducing sextant sights to obtain lines of position. Methods described in detail are: Law of Cosines using a scientific calculator; The Nautical Almanac Sight Reduction Tables (NASR method); Modified Ageton; HO-229; and HO-249.
The full NASR and Modified Ageton tables and excerpts from HO-229 and HO-249 with a Sight Reduction Form for each of the five methods are included to facilitate working sight Practice Problems. Answers to the Practice Problems are shown on the appropriate Sight Reduction Forms. The manual is printed in a loose-leaf style for insertion into a three-ring binder. This makes it possible to remove and make copies of each of the five single page Sight Reduction Forms to work the sight problems and to have extra copies for future use.
Sight Reduction Methods will be useful for recent JN and N graduates to become familiar with the methods taught by USPS in previous years as well as for veteran JNs and Ns who would like to update their skills with the methods currently being taught in USPS courses. With all five methods conveniently assembled in one volume, Sight Reduction Methods should be a "must" for inclusion in any serious USPS library.
