Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Solving an annoying equation please help

  1. Jan 11, 2008 #1
    [SOLVED] Solving an annoying equation... please help


    I'm playing with the code used to convert between on-screen pixel co-ordinates and geographical lat-lon in Microsoft's Virtual Earth. They have a page that explains how to go one way (including example code) at http://msdn2.microsoft.com/en-us/library/bb259689.aspx" [Broken] but it only explains how to get the pixel co-ordinate from a lat-lon and not the other way around.

    I decided it shouldn't be too difficult to solve myself so I started on it. I'm now stuck at the following point:

    a = (1 + sinLatitude) / (1 - sinLatitude)

    I need to calculate "sinLatitude" in terms of "a" but I don't seem to be able to do it. Can anyone please give me some pointers, or do I need to approach the whole thing another way?

    Many thanks,

    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Jan 11, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    Is sinLatitude = (a-1)/(a+1) the answer you are looking for?
  4. Jan 11, 2008 #3
    After running a few tests, it certainly seems to be!

    Many thanks for your help!

    Last edited: Jan 11, 2008
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook