VIA Technologies EPIA SN-Series Specifications download pdf (Page 61)

FASTER Planning Software

5.4.2 Trajectory Determination

The FASTER_planner.m script is responsible of the trajectory determination. This

script requires the following entries:

 Target area UTM coordinates, coming from the GEOtoUTM.m script;

 Surrounding area offset in m, is a squared surrounding area applied to target

area in order to take into account errors;

 Quality, this variable tells the software how many waypoints have to be used

in order to generate the trajectory; settings are low, medium, high

 Optical parameters, inputs are the focal length , the lens field of view with

respect to diagonal  , the horizontal field of view  and the vertical

field of view  (if the sensor is squared  must be set equal to the

); optical parameters are pre-calculated using FASTER_geometry.m

script, described in Chapter 4.

 Overlap; along- and across-track overlap percentage must be declared

 Flight parameters, expected ground speed  and turn rate  must also be

inserted

Given these inputs the preliminary operations are calculation of the square

surrounding area and the definition of the flight height using the digital elevation model

of the target area. Latitude and longitude boundaries are retrieved and the square

surrounding area is applied (see Figure 42). From the surrounding area center, the 3 km

range is applied (Section 5.1), where the highest obstacle must be determined in order to

find the appropriate flight height as shown in Figure 43 (Brisighella surrounding area

DEM) and Figure 44 with the computed flight height.

The selected DEM database is the ASTER (Advanced Spaceborne Thermal Emission

and Reflection Radiometer) global digital elevation model (Version 1) developed jointly

by Japan METI and NASA. The ASTER GDEM covers land surfaces between 83° N and

83° S and is comprised of 22600 1° by 1° tiles. It is in GeoTIFF format with geographic

latitude/longitude coordinates and 1 arcsecond (approximately 30 m) grid. It is referenced

to the WGS84/EGM96 geoid. Its estimated accuracies are 20 m at 95% confidence for

vertical data and 30 m at 95% confidence for horizontal data [Ref (28)]. The names of

individual data tiles refer to the latitude and longitude at the geometric center of the

lower-left corner pixel, example presented in Figure 43 and Figure 44 use the

ASTGTM_N44E011.zip file.

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VIA Technologies EPIA SN-Series Specifications Page 61