Results 1 to 3 of 3

Math Help - (Practical)Calculating the time of day with angles relative to the position of thesun

  1. #1
    Junior Member Greymalkin's Avatar
    Joined
    Jun 2012
    From
    Montreal
    Posts
    74
    Thanks
    1

    (Practical)Calculating the time of day with angles relative to the position of thesun

    Hey guys, I havent posted in some time and have recently taken a lot of my spare time to enjoy the great outdoors.
    My inquisitive nature has lead me to try to figure out a way to tell time using only a cammenga military compass, for those of you who dont know what it is it allows you to see angles(or azimuth)to navigate using your relative position to magnetic north.
    (Practical)Calculating the time of day with angles relative to the position of thesun-web_417-hr.jpg

    I am certain it is possible to tell time with a fair amount of accuracy using only the compass given your latitude and time of year.
    What I am not certain of is how to go about calculating this, I think this has more to do with physics than calculus, but basic calculus is the highest level of math I am capable of at the moment.

    If someone could point me in the right direction that would be great. Ultimately I was wondering if there were some kind of function, or better yet an online calculator to create such a function given a set latitude.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member Greymalkin's Avatar
    Joined
    Jun 2012
    From
    Montreal
    Posts
    74
    Thanks
    1

    Re: (Practical)Calculating the time of day with angles relative to the position of th

    anyone?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor ebaines's Avatar
    Joined
    Jun 2008
    From
    Illinois
    Posts
    1,050
    Thanks
    288

    Re: (Practical)Calculating the time of day with angles relative to the position of th

    If you're willing to live with an accuracy of plus or minus about 30 minutes, you can calculate time by considering the angle between the sun's azimuth position and due south. Assuming you are in the northern hemisphere - at noon the sun is due south, and it moves along the ecliptic at a rate of 15 degrees per hour. So the time is 12:00 noon + (Az degrees)/15, where Az degrees is positive for west and negative for east. So if you can measure the sun's azimuth (degrees east or west of due south, regardless of its altitude) you can get a rough estimate of time. You would need to throw in a correction for your position east-or-west within your time zone, and you would need to add one hour in the summer to account for Daylight Savings Time. Finally, there's a very complicated correction that you could add based on the "equation of time" which takes into account the effects of the earth's orbital path throughout the year. When the earth is near apogee (furthest from the sun, around the first week in July) the sun takes less than 24 hours to go from zenith on day 1 to zenith on day 2, and therefore your clock using this method will run a bit fast, and when the earth is as perigee (the first week of December) this clock runs slow. These corrections may account for up to 1/2 hour error plus or minus. If you're interested in details on the equation of time post back, or try a google search.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 4
    Last Post: January 26th 2011, 02:11 PM
  2. Position-time graph
    Posted in the Math Topics Forum
    Replies: 3
    Last Post: October 14th 2009, 12:28 PM
  3. position and time, derivative.
    Posted in the Calculus Forum
    Replies: 3
    Last Post: September 20th 2009, 01:29 PM
  4. position vector at time t
    Posted in the Calculus Forum
    Replies: 2
    Last Post: September 16th 2009, 04:56 AM
  5. Calculating position on a circumference
    Posted in the Pre-Calculus Forum
    Replies: 7
    Last Post: April 13th 2007, 05:51 AM

Search Tags


/mathhelpforum @mathhelpforum