In this formula, λ means the geogr. longitude of your site and λB the longitude your time zone belongs to. 1:00 hour must be added if you want to get the result in daylight saving time. The equation of time (eot) describes the difference between apparent time and mean time. In the days around our project day, at 12:00 UT the equation of time will have the following values:
date | eot |
---|---|
April, 19 th | 0:01:13 |
April, 20th | 0:01:26 |
April, 21th | 0:01:38 |
April, 22th | 0:01:50 |
April, 23th | 0:02:01 |
April, 24th | 0:02:12 |
April, 25th | 0:02:22 |
April, 26th | 0:02:32 |
in which t means the number of the date in the year. For January, 1rst, is t=1.
t0-60min, t0-45min, t0-30min, t0-15min, t0-10min, t0-5min, t0, t0+5min, t0+10min,t0+15min, t0+30min, t0+45min, t0+60min.
Your sheet should then view similar to the following picture:
This value of RE gives you an impression of the precision of the measured positions.
back to the project page
1 To be truly we must emphasize that the evaluation normally becomes circular at this point: We want to measure the earth's radius but we use it by calculating the distance between the observers from their geographical positions! The only way of breaching this circle would be to measure the needed distance by oneself: by bike, by car, ... Perhaps some measures of quite near observers will be exact enough to evaluate their results, to measure their distance and to get a satisfying - and circle-free! - value of the earth's radius.