|040218 Re: Hr & Hms missing on certain models|
Message #7 Posted by Antoine M. Couėtte on 18 Feb 2004, 4:57 p.m.,
in response to message #1 by Terry Ingram
Feb 18 , 2004
Hi Terry ,
- In Astronomy , it has been a well established tradition to define angles as degrees , minutes and seconds ( e.g. : 53°17'25.4" , 175°18'06.7" ) or Hours , Minutes and Seconds for Right Ascensions , a system quite similar to the one in use in your Surveying Disciplines . Still , decimal degrees ( 2.256789 ° ) or Radians start being commonly used too .
- Formerly , in Sea Navigation , probably until early 20 th Century - sorry I cannot remember exactly when ... - position angles were also commonly expressed as degrees , minutes and seconds . They have since been expressed as degrees , minutes and decimal minutes (e.g. N 28°18'7 , W 042°25'4 ),
- Likewise , in Air Navigation , after initially using degrees , minutes and seconds , further to the extensive use of inertial navigations systems since the early 70's , it has become the ( general ) habit ( and rule ) to define position angles as degrees , minutes and decimal minutes ( e.g. N 46°30'2 , W 000°54'8 being my Home coordinates ) .
*** In other words , in Astronomy to-day HR & HMS remain essential while conversions between Decimal Degrees and Degrees , Minutes and tenths of minutes remain essential in Sea and Air Navigation .
Best Regards ,
Antoine M. " Kermit " Couėtte