Monday, July 25, 2011

Hybrid Ex-Meridian Method

Bowditch table 29 value (a) combined with a slide rule or calculator using the formula (a)(t^2)/60 generates a correction in minutes of arc to be added to the altitude (Ho) of an observation made within 30 minutes time of meridional passage. The sum is then solved as a standard meridional passage observation to get the Latitude [Lat.=90°- (Ho+ corr).~Dec.]. This hybrid method saves page turning, interpolation, and button pushing while adding precision.