NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robert Pearson
Date: 2018 Sep 5, 10:53 -0700
Interesting picture Dave, Thanks.
Using a Celestaire Astra III Professional sextant with a NASA emblem affixed. I believe it's currently manufactured by Changzhou Celestaire Instrument Co Ltd. An excellant Chinese made instrument. It's more than sufficient for marine navigation on earth. The stated accuracy is +/- 15 arcsec.
I have a GLH130-40 manufactured in 1988 by the China Changzhou Shipping Equipment Plant in my collection. The stated accuracy is 40 arc seconds peak to peak value. I'd interpret that to be +/- 20 arcsec. It's equivallent to Celestaire's Astra IIIB. Of course the certificate says free from errors for practical use across the full arc. It's was used by a Canadian yatchman just a few times and is in excellant condition. One of these evenings I'll be making a rough check on it's accuracy taking some star to star distances. Something like the ISS astronauts in the ongoing experiment. See below for some addition info on the experiments.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7646
Robert Pearson
