Posts on ikml.com

A DJI Drone Mission KMZ and What a GIS Import Would Drop

Sun, 25 Oct 2026 00:00:00 +0000

Drone mapping and inspection work runs on mission files. DJI’s planning software saves a mission as a KMZ that holds a folder called wpmz, with a template.kml describing the route and a waylines.wpml file the drone’s controller actually flies. The KML uses DJI’s own wpml namespace for everything a drone needs: heights, speeds, gimbal angles, what to do at each waypoint.

A survey company that receives one of these and wants to see the route on its own maps usually opens it in a GIS or converts it to GeoJSON. The waypoints come through. Almost nothing else does, and nothing says so.

Checking Private Site Plans Without Uploading Them Anywhere

Sun, 25 Oct 2026 00:00:00 +0000

Some geographic files shouldn’t leave the building. A utility’s network map, the plot boundaries of a development that hasn’t been announced, the survey of a client’s site under an NDA, the locations in an investigation. These are exactly the files people need to check before importing them somewhere, and exactly the files that can’t go to an online converter.

Most web-based map tools upload the file to a server to process it, and many fetch map tiles for a preview, which tells a tile server which part of the world you’re looking at. Neither is acceptable for a file you’ve been asked to keep private.

Google My Maps Export to GeoJSON and Which Styles Survive

Sun, 25 Oct 2026 00:00:00 +0000

Google My Maps is where a lot of maps start: a school trip, a list of venues, a delivery route, built by someone who never opened a GIS. When the map needs to go somewhere else, My Maps exports it as KML or KMZ. Each layer becomes a folder, the colour and icon of every pin becomes a pair of styles, and the table of extra fields becomes ExtendedData.

Then someone converts that to GeoJSON for a website, and the map comes out grey.

GPS Tracks With Timestamps and What Happens to Them in GeoJSON

Sun, 25 Oct 2026 00:00:00 +0000

A GPS track in KML is more than a line. Google’s gx:Track element stores a time for every position, so a ride, a run or a vehicle’s day can be replayed, measured for speed and matched against other data by time. Fitness devices and tracking apps also attach values per point, such as heart rate or speed, as SimpleArrayData.

A plain conversion to GeoJSON turns the track into a LineString, and the times are gone. The line is still there, so it looks fine on a map, until someone asks how long a stretch took.

How iKML Was Tested With Hand-Written Exports, Random Round Trips and Fuzzing

Sun, 25 Oct 2026 00:00:00 +0000

iKML makes two kinds of promise. When it reads a map file, it should report what’s really wrong with it, in a place you can find. When it writes a file, the shapes should come out where they went in. The tests check both, and this page says how.

Every number here comes from the test/results folder of the code repository. A script runs all the tests and writes those files, and the site quotes only what they say.

iKML 0.1 Shows What Is Inside a KML, KMZ or GeoJSON File Before You Import It

Sun, 25 Oct 2026 00:00:00 +0000

Somebody sends you a map file. A KMZ from a drone pilot, a KML export from Google My Maps, a GeoJSON layer from a city’s open data portal. You open it in QGIS, or upload it to a web map, and something is off: a few points are missing, a polygon doesn’t draw, the icons are grey squares, half the attribute columns are gone. Nothing told you why.

iKML 0.1 tells you first. It opens KML, KMZ and GeoJSON files, shows what’s inside them, flags what’s broken, explains exactly what a conversion to another format will lose, and writes a cleaned copy with a list of every change.

KMZ Files That Point to Pictures on Someone Else's Computer

Sun, 25 Oct 2026 00:00:00 +0000

A KMZ is supposed to carry its pictures with it. That’s the reason it exists: the KML document goes into a zip archive together with the icons, the photos in the descriptions and the images of any overlays, and the whole thing works anywhere.

It only works if the document refers to the copies inside the archive. When someone builds a placemark in Google Earth with an icon from their desktop, or pastes a photo into a description, the reference can end up as a path on their own computer. They see everything, because the files are right there. Everyone else sees a broken image.

Swapped Latitude and Longitude Sends Points to the Wrong Side of the World

Sun, 25 Oct 2026 00:00:00 +0000

KML writes every position as longitude first, then latitude: 34.78,32.08 is a point in Tel Aviv. Most people say coordinates the other way round, “latitude, longitude”, because that’s how maps and phones show them. So when somebody types a few points into a KML file by hand, or a script builds one from a spreadsheet with the columns in the wrong order, the numbers go in backwards.

The file is still valid. Every number is in range. It opens without an error. And every point lands somewhere else entirely: 32.08,34.78 read as longitude 32.08, latitude 34.78 is in the sea just off the west coast of Cyprus. Swap the numbers for Zurich and you get a point in the Horn of Africa.

Unclosed Polygon Rings in a Field Boundary File and How iKML Cleans Them

Sun, 25 Oct 2026 00:00:00 +0000

A polygon in KML and GeoJSON is a ring of positions that ends where it starts. The last position must repeat the first, exactly. It looks redundant, and that’s exactly why it gets left out: a farm management app, a script that turns a CSV of corners into KML, or a person editing coordinates by hand writes the four corners of a field and stops.

What happens next depends on the program reading the file. Some close the ring silently. Some draw it as a line, so the field has an outline but no area. Some refuse the shape, and the field is simply missing from the map, with the other fields drawn around the gap.

What KML, KMZ and GeoJSON Are and Why Map Files Lose Data on Import

Sun, 25 Oct 2026 00:00:00 +0000

Most map data that moves between people moves in one of three formats. They look interchangeable, and every tool converts between them. They aren’t interchangeable, which is why so much goes missing on the way.

KML: Built for an Earth Viewer

KML, the Keyhole Markup Language, was made for the program that became Google Earth. Keyhole, the company, was bought by Google in 2004. Google later handed the format to the Open Geospatial Consortium, and KML 2.2 became an OGC standard in 2008.

Why the Map File Inspector Is Called iKML

Sun, 25 Oct 2026 00:00:00 +0000

iKML is two parts: the “i” of inspect, and KML.

KML is the format the tool reads most, and the one people struggle with most. It’s the Keyhole Markup Language, named after Keyhole, the company whose Earth viewer became Google Earth. Today it’s an open standard of the Open Geospatial Consortium, which is why any tool, iKML included, can read and write it freely. iKML reads KMZ and GeoJSON too, but KML is where the trouble usually starts.