Don Casey - Dragged Aboard Dragged Aboard by Don Casey
A Cruising Guide for the Reluctant Mate


      

Other books by Don Casey
| Home | Mailing Lists | Bookstore | Weather | Tide Predictions | Bowditch |

Corrections for refraction in deserts

From: Geoffrey Kolbe (no email)
Date: Sun Mar 05 2006 - 12:18:25 EST

  • Next message: Philip Lange: "Re: Use of a sextant contravenes H&S legislation!"

    I am off to the Libyan desert at the end of March to see the total eclipse
    which has its maximum period of totality in the Southern Sahara. I will
    then be spending a couple of weeks wandering around the South Eastern
    Libyan desert with a group looking at various natural wonders, and
    finishing off at Gebel Uweinat on the Libya Egypt border to see some
    Saharan rock art.

    The group will naturally have GPS receivers to keep them found, but that
    need not stop me using celestial navigation to plot our progress - and
    amuse the rest of the group showing them how it was done "in the old days"!

    Of course, due to the high temperatures (40 to 50 Centigrade) corrections
    will have to me made to the standard Altitude Correction tables. But it
    occurred to me that the Refraction Correction Tables for Non Standard
    Conditions in the Nautical Almanac may not be appropriate in the middle of
    the Sahara, where the hot sand will bake the air near the ground.

    Does anyone have any data on altitude corrections for desert conditions?

    Thanks

    Geoffrey Kolbe


  • Next message: Philip Lange: "Re: Use of a sextant contravenes H&S legislation!"



    | Home | Mailing Lists | Bookstore | Weather | Tide Predictions | Bowditch | Trawlerworld |