The Study Of Astronomical Navigation Simulation Teaching System

With the development of GPS navigation systems,the celestial fixing is no longer placed high importance on by the mariners.However,astronomical navigation is the most basic and,reliable,method of navigation,at the same times its equipment is simple,independent and stable,which are characteristics.that other positioning systems including GPS do not have.In addition,in the ocean voyage the only way to check compass error is the use of celestial,and this work has included in the astronomical navigation..However,celestial fixing needs to finish amounts of look-up table and calculation. Also the contents and the amount of labor is very large.Therefore little attention is also prone to miscalculation.The rapid development of computer technology provides a new opportunity for astronomical navigation.Using computer to.develop new calculation and navigation systems,you can make a gradual move away from the backwards situation of celestial fixingCompleted the following content in this paper:(1) Celestial Fixing Software1) Calculating positions of celestial objects:By inputting the GMT,obtain the sun right ascension,declination,Greenwich hour angle and the vernal equinox Greenwich hour angle.2) Seeking latitude through the sun meridian altitude:input the ship time,course,speed,estimated position,then we can know sun meridian zone time.Then at the sun transit,observe the sun altitude,through the calculation,obtaining the latitude.3) Seeking latitude through Polaris altitude:By inputting ship time,estimated position,instrument error,index error,height of eye,chronometer time of stopping stopwatch,chronometer error,stopwatch reading,Polaris altitude and so on,can directly seek the latitude.4) Running fixing by sun:By inputting ship time,course,speed,estimated position,instrument error,index error,height of eye,chronometer time of stopping stopwatch,chronometer error,stopwatch reading,altitude of sun under edge at the observation and altitude of sun under edge at the transit,seek the observed position.5) Fixing by two star bodies:By inputting GMT,course,speed,name of star bodies,altitude of star bodies,seek the observed position.(2) Software of measuring compass error:1) Seeking compass error by low altitude of sun:By inputting ship time,estimated position,compass bearing at the observation,seek compass error.2) Seeking compass error by Polaris:By inputting ship time,estimated position,compass beating at the observation,seek compass error.(3) Starfield running simulation software:By inputting observation time,can observe the situation of starfield simulation running.