mSolar

Solar observation is a method of measurement to determine the azimuth of a line astronomically, that is, by doing divination to the sun.
Sun observation can be done either in the morning or evening. However the altitude of observation to the sun should be at least 10 °.
At least two (2) sets of continuous observations, with each set of observations containing two (2) averages to the center of the sun at the left and right intersections. The third set (3) shall be taken if the grid bearing difference between the first set (1) and the second set (2) exceeds 10 ”.