A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2019 Mar 6, 23:12 -0800
Has anyone successfully made and reduced a cell nav sight from a train? I ask because at home I am restricted to using an AH yet a few days ago I had a ten or fifteen minute window in which to take a sight from a train using the horizon. Of course Sod's law applied and I did not have my sextant with me.
In the photo the sun has an azimuth of 38 degrees east (from a phone app). The sun and horizon were clearly visible. The photo was taken through double glazing but at the rear of the train was an open viewing platform ideal for sight taking. The train was moving dead slow as the area had suffered major damage in a 2016 7.8 magnitude earthquke. Consequently the ride was very smooth.
The big unknown is the height of eye above sea level. Note that iIn the 2016 earthquake the land on this coast was raised by several metres. An increase of four metres changes the dip by 3.5'.