The Intet national Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008
4.2. Determination of the solar radiation
The solar radiation is determined from the solar radiation
database. Solar radiation is determined in MJ/m 2 /year. It
depends on the location of the object in the particular radiation
zone. Medium values for those 4 zones are varying from 3700
to 4500 MJ.
Figure 6. Solar determination radiation regions (alpine, dinaric
mountain, panonian basin and Mediterranean region),
4.3. Area of the object
In case of the parcel, the area is determined directly from land
cadastre. If the object is building the area of the roof is
determined directly from cadastre of buildings or by counting
the pixels (0,5m x 0,5m) in digital orthophoto. In both cases the
area has to be corrected by the inclination factor.
| Parcefs 2403.shp
□
Plan shp
□
| Sis vàe. shp
[=□
Dkn.shp
□
G25«?062c.tif
Segment Length: 9.68 m Perimeter: 72.36 m Area: 254.69 sq m
Figure 7. Area determination
4.3. Azimuth
Azimuth determination for parcels is determined by digital
slopes orientation database.
Figure 8. Azimuth determination for parcel
The azimuth of the roof can be determined through computation
based on the measured coordinates of the relevant points on the
roof. Due to simplicity the azimuth in the operational
photovoltaic system is defined just by overlaying a compass
based diagram on the displayed object. The reading is recorded
manually.
Figure 9. Azimuth determination for object
4.4. Inclination
Inclination of the roof is determined by using formula
b
tga = -
a
where b = roof height obtained from the cadastre of buildings
a = horizontal component of a steep, measured from
DOF
55