🛩️ Drone Survey Planner
A mapping flight photographs the same ground many times on purpose. So the camera footprint is not the swath — and acres-per-battery, computed without that, is a number no survey has ever achieved.
Overlap is not a detail, it is most of the flight
The coverage calculator on this site is honest about its own limits: its description says plainly that it ignores turns, overlap and headland passes. The trouble is that nothing here then puts them back, so the figure it prints is the one that ends up in the quote — and the reader has no way to know how far off it is.
Overlap is the largest of the three by a wide margin. Photogrammetry works by seeing the same feature from several positions, which means the aircraft deliberately re-photographs most of what it just covered. What advances per pass is the footprint reduced by the sidelap, and at the overlaps a survey grid is actually flown that is a fraction of the frame. The pass count goes up in proportion, and so does everything downstream of it.
Then the passes themselves cost. Each one ends in a turn that covers nothing, and with the pass count now large those turns add up. Batteries run out mid-block and get changed, which is minutes on the ground in the middle of a paid day. None of it is exotic; it is just absent from the multiplication.
The practical consequence is a quoting error rather than an academic one. An operator who commits to a day rate on the bare coverage figure has agreed to a job that takes substantially longer than the price assumed, and discovers it on site, with the client watching.
❓ Frequently Asked Questions
Why is the area per battery so much lower than the coverage calculator says?
Because that calculator multiplies endurance by speed by swath width, and its own description says it ignores turns, overlap and headland passes. Overlap is the big one. A mapping flight photographs the same ground repeatedly on purpose — photogrammetry needs a feature to appear in several frames before it can be placed in three dimensions — so the aircraft advances only a fraction of its camera footprint on each pass. Hand the footprint to that calculator as the swath and it returns the area you would map with no overlap at all, which is not a survey; it is a set of unrelated photographs.
Where does the footprint come from? I only entered GSD inputs.
It is the ground sampling distance read across the frame instead of per pixel. The GSD calculator already returns centimetres per pixel from your sensor width, focal length, image width and altitude; multiply that by the pixel count and divide by a hundred and you have the footprint in metres. Nothing new is assumed, and because it derives from the same figure that page prints, the two cannot disagree about the same camera at the same height.
How much sidelap should I use?
That is a question about your processing software and your terrain, not about flying, so this page prices the choice rather than making it. Too little and the reconstruction fails outright, which means the entire flight was wasted — so the cost of too little is not a slightly worse model, it is everything. The table shows passes, batteries and time on site across a range so you can see what each step actually costs before you commit to it. Uniform terrain and strong texture tolerate less; trees, water, sand and anything repetitive want more.
Why do turns matter enough to model?
Because overlap has just made the number of passes large, and every pass ends with the aircraft slowing, turning, and coming back up to speed while covering nothing. On a tight block with heavy sidelap that can be a real share of the time in the air, and it is time that consumes battery without producing a single usable frame. Time one of your own turns rather than trusting a figure here — it depends on your aircraft, its speed, and how the flight is programmed.
Does it really not agree with the coverage calculator even with everything set to zero?
Almost, and the residue is honest. Set both overlaps and both time penalties to zero and the swath becomes the footprint exactly and the penalties vanish exactly. What remains is that a block takes a whole number of passes: you cannot fly four fifths of a line, so the last pass re-covers ground already covered and the aircraft flies slightly further than the bare area implies. That residue is real rather than an artefact, and it shrinks to nothing when the block width happens to divide evenly by the swath.
Can I quote a job from this?
It gets you much closer than acres-per-battery does, because it gives time on site rather than a theoretical coverage rate, and time is what you sell. It does not cover travel, setting up, ground control points, the flight that gets aborted for wind, or processing — and processing scales with the photo count, which is why that number is shown. Treat it as the flying portion of the day, computed properly, rather than the whole quote.