MP Survey Grid issue


I am using Mission Planner Ver 1.3.38.

We are using Sony A5100 camera & use the pic taken from it as sample photo for preparing the survey grid. We have permissions to fly at 245 m with 85% forward overlap and 40% side overlap & fly a custom built fixed wing plane running on Pixhawk.

While planning the missions, I suspect that MP creates more number of legs - for example with the aforesaid parameters, to cover 1 square kilometer polygon (1 km x 1 km) it makes 18 imaging legs. When the altitude is changed to 300 m, it results in 15 legs.

Is there something wrong that we are doing OR is that MP is miscalculating the distances based on camera parameters, resulting in more number of legs. This substantially affects the yield per mission, while planning.

Conversely, when this plan is executed, the yield is almost 2.5-3 times more; this once again throws all planning & ground control point collections off course.

We have experimented by changing the side overlaps to 20-30% resulting in bad quality data. So 85-40 seems to be the best fit for the output that we require.

Having said this, I shall appreciate if someone can please guide me on how to arrive at a most realistic yield estimates while planning.

Thanks & best regards,


can you post a screenshot of the settings you are using?