ASSET Software
Photo Sets
Starting with version 1.24, the software can be used to assemble panoramas with either 7 or 9 pictures in a row and either 1 or 2 rows of pictures.
A 7 picture panorama (Figure 12) spans a range of angles from 75° (15° north of east) to 285° (15° north of west). A 9 picture panorama (Figure 13) spans a range of 45° (northeast) to 315° (northwest).
For the best shading estimate, take 9 pictures for tracking arrays or arrays with a tilt of zero (flat) since both those types of installations capture energy whenever the sun is up. For a fixed array with tilt equal to the latitude, facing 180° (south), there is typically less than 0.1% energy captured in the additional angular range of the 9 photo set, so it is sufficient to use a 7 photo set to check shading. The amount of energy captured in the extreme ranges varies with latitude, but we recommend a 7 photo set for fixed arrays with tilt greater than 15° and azimuth between 135° (southeast) and 225° (southwest). Note that this is just a time-saving recommendation since a 9 photo set can be used for any installation.
Figures 12 and 13 illustrate the difference between a 7 and a 9 photo set. Note that the first picture of a 7-photo set is taken with the camera facing east, while the first picture of a 9-photo set is taken with the camera facing one detent position north of east.
Figure 12: 7x1 photo set
Figure 13: 9x1 photo set
A good site generally has full sun exposure from 9 in the morning until 3 in the afternoon when the sun is at its highest elavation. For those rare cases where there is some shading even with the sun high up, 2 rows of pictures can be taken. Figures 14 and 15 are expamples of 2 row photo sets with 7 and 9 pictures per row, respectively. In both cases, pictures for the first row should be taken from east to west, typically at 25°. For the second row, the ASSET tilt angle is changed to 45°, then pictures taken from west back to east. Note that there are no obstructions in the second row of these two photo sets, so that row is unnecessary.
Figure 14: 7x2 photo set
Figure 15: 9x2 photo set
