r.sun: wrong sign in equation of time
|Reported by:||tomhuld||Owned by:|
Description (last modified by )
Bug report ticket #2876 by fabriziosossan reported a problem with the equation of time in r.sun, whereby the calculation of the solar time from the clock (civil) time is wrong. The problem was fixed with a patch for GRASS 6, but as far as I know there the fix was not applied to GRASS 7.
I would like to suggest the following patch for r.sun/main.c. Since this is my first patch for GRASS, apologies if I'm doing it worng.
--- main.c (revision 67790) +++ main.c (working copy) @@ -1766,7 +1766,7 @@ * "local clock time". */ dayRad = 2. * M_PI * day / 365.25; locTimeOffset = - -0.128 * sin(dayRad - 0.04887) - 0.165 * sin(2 * dayRad + + +0.128 * sin(dayRad - 0.04887) + 0.165 * sin(2 * dayRad + 0.34383); /* Time offset due to timezone as input by user */