Adding information about your neighbourhood to OpenStreetMap can be relatively simple when there is local data to use as landmarks. Sometimes you want to explore terra incognita and add data for which there is no local reference for dead reckoning. This tutorial takes a first look at using a GPS receiver to collect a track file for use as a reference when adding information to OpenStreetMap.
Using a GPS receiver to collect data for OpenStreetMap is very helpful for a scenic bicycle trail or relaxing canoe trip.
Select a GPS
There are many GPS receiver devices that will work well for use with OpenStreetMap.
- Preferred GPS features
- Accepts a media (micro-SD) card for extra storage
- Saves track files at 1 point per second in GPX format
- Many hour battery life
- USB connection to computer (or Bluetooth if that suits you)
- Will display OSM map
- Will navigate with OSM map
- Rugged and water resistant
Many devices fit this description at varying prices. See the comprehensive GPS reviews from the OSM point of view.
- GPS receivers to avoid.
- The GPS receiver in your phone - it's probably inaccurate.
- GPS receivers intended for your car - Probably terrible battery life and difficult to change settings.
- A GPS receiver that plugs into something else for power - Will probably drain the battery.
You'll have to check the manual for your device to adjust the settings.
- Settings that you'll want to adjust or confirm are
- Install additional storage media.
- Track file settings
- "Save track file" to on.
- Track file format to "GPX".
- Save track files to data card.
- Save track points by time.
- Save track points every 1 second.
- Turn "Lock on road" or "jump to nearest road" off.
- Turn the backlight off to increase battery life.
A GPS receiver doesn't know exactly where it is at every second, but it believes that it does. Bear this in mind. The GPS receiver will happily lie to you. Bad reception, interference, poor weather, overhead foliage, nearby buildings, narrow streets or canyons can all reduce the accuracy of the data saved by your GPS receiver.
Also, GPS receivers seem to do a better job of detecting your position if you are moving faster than a jogging pace.
Your GPS receiver will take a few minutes to
lock on to your location after you switch the device on. Lock on can be faster if you stay in one place with good reception before you start your survey.
Create a track file
Now that you have a suitable GPS receiver, have it configures correctly, have it switched on, and locked on. You can go and do your survey. Make notes in your log book about what you observe and about each thing that you want to tag later. All the while your GPS will be collecting information in your track file.
Upload track file to OSM
Once you complete your survey, connect your GPS receiver to your computer by USB or bluetooth and retrieve the saved GPX file. Send that file to OpenStreetMap so that others, including your future self, can benefit from your survey. Imagine if you survey streets one day then avenues another, and contribute both GPX files to OSM, you'll be able to use that entire GPX file grid in your tagging.
Some people like to trim their GPX files to just the area of their survey before uploading. The gpx-edit plugin for josm is very helpful for trimming gpx files before uploading.
Upload your GPX trace http://www.openstreetmap.org/trace/create
You can inspect all of your previous GPX uploads, http://www.openstreetmap.org/traces/mine
Or look at a specific upload in detail. http://www.openstreetmap.org/user/rw__/traces/772096
Various editors allow you to refer to uploaded GPX tracks while editing.
This tutorial is one of a series of tutorials for OpenStreetMap beginners. Find more tutorials here.
This archived article was originally published on Sun, 07/25/2010 - 15:52.