NavList:

RE : http://fer3.com/arc/m2.aspx/Longitude-calculator-theodolite-Pennino-jun-2013-g24529

Hello Bruce,

Thanks for your reply.

Yes, you seem enthusiastic ! Theodolite measurements can be deadly accurate simply because the local vertical can be known very accurately, and also because you do not have to worry about Horizon Dip, which has remained (and will likely remain) our biggest unknown (and inaccuracy source) in conventional CelNav.

*******

You estimate your overall accuracy as follows : " overall accuracy is plus or minus 12 seconds of arc? "

Actually you did perform MUCH better !

In my last post (which you might not have spotted as I might feel)

" http://fer3.com/arc/m2.aspx/Longitude-calculator-theodolite-Couëtte-jun-2013-g24512 ",

and from working your AVERAGED DATA with the super accurate INPOP10a Ephemeris + the following assumptions : P = 990mb = 29.23"Hg *** T = 20°C = 68°F I showed that you observations accuracy was 3" (3.25" actually) !

Very Good !!!

The only way to further improve our current knowledge of your sightings would be to accurately know the following data :

What were the actual temperature and the actual pressure (at Observer's level i.e. QFE, or by default Area QNH for a nearby airport at a similar elevation) when you performed your observations ? For my calculations, I could use only best estimates so far for these parameters.

Any such recorded data (pressure and temperature) in your files ?

Thanks in advance

Best Regards

Kermit

Antoine M. Couëtte

----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------