NavList:

I figured that I need to give some LOP data to reduce with all of these people building and using their Bygrave's slide rules, and to stir the pot a bit on the list.  So in order to kill two birds with one stone, I offer the attached Excel spreadsheet.  Lying therein are a plethora of upper limb moon LOP's which should allow eager navigators to fix the position of my ship.  There are a few features of particular note that should appeal to certain members of the list.

 

1)  The given DR is a real DR tracked from the AM star fix some 14 hours earlier

2) The moon is fairly close to the celestial equator (please note the LARGE hourly change in declination)

3) The ship's track is at a fair clip and nearly Southerly.

 

These should be considered fairly extreme conditions to work out the Latitude and Longitude of the ship; the first position from many LOP's away from upper transit, and then again around the time of transit.

 

I will be most appreciative if people who solve the transit portion graphically can post an image or file of their curve and to see what the  1900L fixes is. (ZD -9)

 

I offer the following challenges:

1) what would you calculate the local zone time of transit to be?

2) what was the 1800L fix?

3) what was the 1900L fix?

4) what was the actual local zone time of transit by observation?

5) most critically, how much faith would you put in these fixes?

 

I will post the actual GPS fixes and my celestial solutions for both times at a later time.

 

Have fun!

 

Jeremy