Automatic Flight Planning for Unmanned Aerial
Vehicle Utilizing GIS Analysis on Digital Elevation
Model
2. DETERMINING PARAMETERS
Determining an optimum flight path, which minimise the risk of aircraft loss, while maximise
the chance that mission objectives are fulfilled is a complicated and time-consuming task. A
number of factors, sometimes conflicting, must be carefully considered. These factors can be
divided into five groups namely. 1) Mission date, 2) airfield-control station-target positions, 3)
aircraft capabilities, 4) sensor mechanical-capabilities, and 5) safety.
To ensure that image of the target can be taken, mission planner must be sure that at the safe
position and appropriate time on the planned mission dates, the target is not in the shadow.
Position of the sun (azimuth and altitude) at each time interval must be calculated and then the
program will compute the brightness value of the target location. The output brightness value
range from 0 to 255 where 0 or small values mean shadow and 255 represents the brightest or
the best for taking a picture. Mission planner then determines whether light condition at the
target is appropriate. The analysis may be repeated until satisfied.
Positions of the airfield where UAVs are launched and landed are used to calculate distance
from the target to check if it is within operational distance of the aircraft. If not, users must
reselect another airfield. Over the target, users will be asked how close and how far a UAV can
be from the target. This is for safety reason and the defined zone will also help narrow the space
for finding out appropriate exposure positions. Other safety factors include no-go zones and
minimum clearance of UAV above ground.
