碩士 / 國立臺灣海洋大學 / 商船學系所 / 95 / Nautical Almanac provided the most important two variables for solving astronomical vessel position (AVP), which were the apparent positions of navigational celestial bodies and the variables of correcting observed altitude of sextant. However, the process of reducing apparent positions became tedious and time-consuming owing to the design of Nautical Almanac. Thus, if the process could be replaced by computer or software without any artificial judgment, it is possible to promoting the efficiency of navigator and avoids the inaccurate AVP.
The parameters, variables and formulae of Nautical Almanac for solving the apparent position were invalid to public due to merchandized. Also, there were not provided in related journals, but only discussing the accuracy of methodology. Consequently, this thesis adapted two academic publications written by Jean Meeus as a major source and extracted the terminology, process, formulae and parameters for calculating the apparent position and developed two Navigational celestial bodies’ Apparent Position computing Software (NavAPS). Besides, this thesis used the apparent positions of navigational celestial bodies generated from the online ephemeris of the Jet Propulsion Laboratory of NASA as a criterion to examine the performance of the NavAPS 1, NavAPS 2 and the Nautical Almanac 2007 commercial edition (NA 2007), respectively. We adapted the paired data t test to understand their mean of difference between the criterion and the method mentioned above. In this way, the NavAPS 2 is the best of three and NA 2007 is better than NavAPS 1. Except the apparent position, the NavAPS could also obtain the horizontal parallax (HP) and Semi-diameter (SD) for correcting sextant altitude to observed altitude. The most important is the Software has a wide time-span from A.D. 1986 to A.D. 2050 and is able to calculate the apparent position of different bodies at one time. Thus the NavAPS 2 could replace the Nautical Almanac during the process of reducing AVP and had a wide application.
| Identifer | oai:union.ndltd.org:TW/095NTOU5728044 |
| Date | January 2007 |
| Creators | Guo-Yu Weng, 翁國祐 |
| Contributors | Chih-Li Chen, 陳志立 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 173 |
Page generated in 0.0116 seconds