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Ask HN: How do I make my own map?
My neighbours and I share a community park that needs surveying. I have been volunteered and am hoping it will be possible with a simple theodolite and free software. If you’ve done your own site survey from scratch, what tools,
software and HOWTOs helped you the most?
- slater 5y agoleaflet.js? https://leafletjs.com/ https://leafletjs.com/
- gorgoiler 5y agoSeems to be for rendering? I’m talking about getting my boots on the ground and measuring where things actually are!
- slater 5y agoD’oh! My bad!
- bigiain 5y agoHow big is the park? And what sort of accuracy are you after? What equipment do you have available and/or what sort ofd budget are you hoping to keep within? For an "on the cheap, lots of DIY" approach - I've got an inexpensive (~$40 from memory) laser rangefinder with sub cm accuracy and a range of a bit over 100m (it'll get ~120m for things with "good" reflective properties, sometimes only 50m or so for "bad" surfaces). If the park is a suitable size, you could probably start with a Google Satellite view, and measure enough distances to triangulate everything to calibrate the satellite imagery. I've considered (but never gotten around to) attaching a 3 axis digital compass module so I can record angles and elevations for each distance measurement. That'd help a lot of there are lots of objects you want to plot positions for - you wouldn't need 2-3 measurements from different known locations for each object that way. See also my other comment about using a drone and photogrammetry.
- gorgoiler 5y agoGreat questions, thank you for you responding. It is a small park, 600ft square, but conservation means we would like to map tree locations precisely. Half a trunk diameter would do: around about 6”. In metric that’s around 200m with accuracy of 200mm. Budget is up to $500. We have time and tech ability on our side, so don’t need a Total Station (something I’ve learned about recently) that can do everything, but it would be nice.
- arthur2e5 5y agoThe more amateur world I am familiar with (OSM et al) does not go for a theodolite at all. The general approach is to satellite-trace the place out and use GPS tracks for what it can’t cover.[1] For more detailed shapes or up-to-date imagery, OpenDroneMap might be used to assemble own drone imagery. [1] https://wiki.openstreetmap.org/wiki/Mapping_techniques The rendering part is usually done by leaflet on the web. GIS software should allow importing from OSM too.
- bigiain 5y agoUsing inexpensive drones and photogrammetry to stitch lots of photos together is fairly straightforward these days: https://www.mobiddiction.com.au/drone-mapping-in-4-steps/ https://www.mobiddiction.com.au/drone-mapping-in-4-steps/ Depends a lot on what you mean by "site survey" though. The photogrammetry used there also created a depth map from the stereography where images overlap: https://www.mobiddiction.com.au/wp-content/uploads/2019/11/Team_Photo_5._V2.jpg https://www.mobiddiction.com.au/wp-content/uploads/2019/11/T... You can see in the bottom right corner of that the elevation changes for the roundabout and the ~120mm high curbs at the edges of the roads - and the gradual slope of the whole site towards the top right corner. (There's a lot more detail and calibration data than that image shows in the full data set there.)