Free drone mapping software: what you get without paying

"Free drone mapping software" is three different searches wearing one phrase. Some people want to fly a mapping grid for nothing, some want to turn photos into a map for nothing, and some want to measure on a map they already have. All three exist. This guide says what each free option actually does, where the paid part begins, and how to get a lot done without paying for it, including with our own software, whose free plan has a limit we would rather say up front.

Three jobs, three kinds of free

1. Flying for free

Every mapping drone comes with a flight planning app that flies a grid at a set height and overlap and fires the camera. That part is free and good. What the free app does not do is make a map: it leaves a folder of photos with GPS tags. If the drone has RTK, a correction source (a network subscription, or a base you own) is the only cost on the flying side; PPK against a public reference station is free. (How to fly so the photos process.)

2. Processing for free

Photogrammetry, the step that turns the photos into a map, has a mature open-source implementation: OpenDroneMap, which runs on your own computer (or a server you rent by the hour) and produces the same three files a paid service does. Clarity's own processing runs it on our machines, with PPK and ground control handled before it starts, so we can say with some confidence that the output is survey-grade when the flight was.

What it costs instead of money:

• A machine. A desktop with a recent graphics card and 32 GB of memory handles flights of a few thousand photos. A laptop handles a few hundred, slowly.
• Setup. An afternoon the first time, with a container runtime and a web interface; less after that.
• Attention. A job that fails at hour three needs someone to read the log, change a setting and run it again. Ground control is a text file you format by hand; PPK is a separate tool again.

For a company that flies a site a month and has a technically minded person, this is a fine arrangement. For a company that flies every week, or has nobody who wants to own it, metered cloud processing (tens of dollars to a couple of hundred a flight) is usually cheaper than that person's time. (Where the costs sit.)

3. Measuring for free

If you already have the orthomosaic and elevation models, from a hired survey, from open-source processing, from a platform you left, a free desktop GIS opens them. QGIS, the standard one, will measure lengths and areas, draw contours from the terrain model, profile a line, and, with a few steps, calculate a volume against a base. It exports anything to anything. What it will not do is the things that make a drone programme useful to more than one person: hold every flight of a site on one timeline, difference two of them, print a volume with the base it assumed, or give the client a link that just opens.

What Clarity gives away, and what it does not

We built it that way for a plain reason: hosting a 2 GB orthomosaic and serving it to a crew costs us money every month, and a free plan that quietly degrades or expires is worse than a small price. Studio is one charge for the organisation, not per seat, which on a site with a foreman, an engineer and a client is the difference between $50 and several hundred. Enterprise, where we process your photos and run PPK and ground control, is priced by how often you fly. (Pricing.)

A free workflow that works

1. Plan and fly in the drone's own app at 75–80% front and 65–70% side overlap, nadir, 80 to 100 m.
2. Lay three or four checkpoints if you have access to a surveyor's rover, or use PPK against a public station.
3. Process in open-source photogrammetry overnight. Keep the orthomosaic, DSM and DTM GeoTIFFs. (What those are.)
4. Open them in a free GIS to check the position against your checkpoints and measure what you need.
5. When more than one person needs the map, or the flights need comparing month to month, put the files somewhere online that does that.

Step 5 is where Clarity sits: upload the three GeoTIFFs and the site is in a browser tab for everyone, with the volumes, the cut and fill and the timeline. Try the tools on the demo quarry first; it costs nothing and tells you whether it is what you want. (Start free.)