Photo overlap and other settings....

Blakedownunder · Mar 15, 2017

Hi Guys,

Not new to using drones for surveying purposes (surveyor by trade) but I am new to the P4 and its good fun!

Just wondering if anyone is prepared to share some technical info with me? Have done a few surveys now just using the DJI GS Pro software, seems ok to me and gets the job done. What are industry guys aiming for with forward and side overlap percentages? I've been playing it safe with 90 and 70 but I'm accumulating way too much data. Any advise as to what I can accurately use when I have the P4 in the air?

Thanks in advance.

Blake

PeteM · Mar 15, 2017

There is no single answer.

Based on what you have to fly over and the purpose for which you are doing it you have to "play" with flight altitude, speed and overlaps to achieve an acceptable result for your needs.

It took me a few months to find the perfect balance for me...

Blakedownunder · Mar 15, 2017

Thanks Pete,

A heap of my flying will be from elevation over existing open cut mine voids and large waste dump rehabilitation... Going to stick with my 50m height and play with the front and side overlap. 90 is crazy for the front, might start at 75 front and 65 side and see what happens. Work from that.

Blake

PeteM · Mar 15, 2017

I advise you not to fall below 80 for frontal overlap.

The side overlap is more complex to choose from and is very dependent on the morphology of what you want to map... in the case of a regular flat land 65 may be right but in all other cases not...

If the photos are too many try to increase the flight altitude of about ten meters... just a little effect on the GSD but great improvements in the number of photos...

Meta4 · Mar 15, 2017

Blakedownunder said:
I've been playing it safe with 90 and 70 but I'm accumulating way too much data.

I've been flying Drone Deploy at 70/70 with good results

Blakedownunder · Mar 15, 2017

Thanks guys, good info.

I'm processing 350 photos as we speak in Agisoft. Setting were;

50m flight altitude
90% Front
70% Side

DJI GS pro doesn't give me area (I'd rather that than distance flown) but the distance was around 2400m worth of waypoint flying at 3.2m/s

Did it with 58% battery left and a battery temp of 52 degrees Celsius on landing (Its warm in Australia where I work, and gets much warmer) outside ambient temp was 38 at take off.

Will fly the same route each day with some varying parameters and see when the information starts to significantly degrade.

Blake

PeteM · Mar 15, 2017

Why not 60m flight altitude ?

Blakedownunder · Mar 15, 2017

Yea Ill try that too, don't want to go too high because I'm mainly surveying pits. I usually take off from outside the pit and as I fly over the edge my altitude in some cases can double. Wouldn't mind keeping a decent ground resolution.