Does the SunEye use magnetic or true azimuth readings? Which one do US state rebate programs use?

For its calculations, the SunEye uses the tilt and azimuth of the fixed panels, frequently the same as the tilt/azimuth of the roof. When entering azimuth, you can define whether you are giving the true azimuth, eg. from a map or Google Earth(TM), or magnetic, that is, from the compass reading. The SunEye knows the magnetic declination for your session location, based on a model built into the SunEye. So both magnetic and true direction is known. When displaying azimuth on the data results, such as in the Annual Sunpath view or the Obstruction Elevation view, the SunEye displays TRUE azimuth, not magnetic, with South as 180 degrees (in the northern hemisphere). For example, in Los Angeles California, the magnetic declination is 13 degrees East. If the user enters 180 degrees magnetic azimuth into the SunEye, the TRUE azimuth of 193 degrees will be displayed in the data outputs. By convention, US state programs normally use TRUE azimuth, and they expect that in applications and reports. Therefore, magnetic readings should be adjusted by the magnetic declination of that location. The SunEye does this automatically.