for the control of a heliostat I have a program for the calculation of azimuth and elevation. Now I am still missing the calculation of azimuth angle and elevation angle for setting the mirror. While searching for examples, I discovered this post here. https://astronomy.stackexchange.com/a/43318/46036 My prototype is located in the northern hemisphere and is aligned in north-south direction. In the rest position, the mirror points to the south (azimuth 90°, elevation 0°). The target is 55° southwest and 30° above the mirror horizon.
Can you tell me with what calculations I can determine azimuth angle and elevation angle of the mirror?
Many thanks in advance! Itsme
thank you very much. Your answer helped me a lot to realize my mistake. I had to remove a servo from the prototype that was a solar tracker and replace it with a stepper motor. Due to carelessness, I positioned the angle sensor incorrectly. Please excuse my incorrect description of the angle position with which I caused corrections of the calculation. After the correct positioning of the angle sensor it now looks like this.
My prototype is located in the northern hemisphere and is aligned in north-south direction. In the rest position the mirror points to the south (azimuth 180°, elevation 0°). The target is 55° southwest and 30° above the mirror horizon.
Now it should be possible with the example from the contribution https://astronomy.stackexchange.com/a/43318/46036 it should be possible to implement the correct calculation.
Is the following calculation correct?
mirrorAz = 55° + (SunAz - 55°) / 2
mirrorAlt = 30° + (SunAlt - 30°) / 2
The azimuth axis currently has the following orientation. North = 0° East = 90° South = 180° West = 270°
At my location it was very cloudy yesterday. In the short cloud gaps I could test the calculations in the afternoon. At that time the SunAz = 213.51° and the SunAlt = 50.18°. These values correspond to the NOAA table.
mirrorAz = 55° + (213,51° - 55°) / 2 = 134,26°
mirrorAlt = 30° + (50,18° - 30°) / 2 = 40,09°
The mirror reflection mirrorAlt reached 30° relatively accurately but mirrorAz is far off. The value of mirrorAz should actually be about 226°.
How can this large mirrorAz difference occur?
With best regards Itsme