My focus as a local guide (and hiking guide) normally centers on locations that lie outside of the normal physical address space, like trailheads and natural features. I’ve noticed that generally those types of locations have been not been as accurate as a street address on Google Maps. So I’ve updated a few marker locations, and here’s how you can do it too (while ensuring accuracy).
What you’ll need:
- A smartphone with Google Maps and location enabled
- A smartphone app to verify GPS status (there are a ton of free ones out there)
- A second GPS device (not another app on your smartphone)
If you’re in the field and notice a discrepancy with a marker, here’s what you do.
1 - Check GPS Status
We first want to make sure that your position on Google Maps is accurate. Sometimes a GPS can have accuracy problems, so let’s make sure we’re actually where the GPS says we ware. A typical accuracy range (for now) is 5m. So fire up your GPS status app and make sure that your (horizontal) accuracy is around 5m or better.
2 - Drop a Pin in Google Maps
Now go back to Google Maps and drop a pin in your current location to mark the correct spot for the location.
3 - Save Your Pin Location
Once you drop the pin, you can save the location to your lists as a starred place, etc. You can also copy the location and save it to your notes.
4 - Cross-Check with Your 2nd GPS
Now it’s time to pull out your second GPS (you can see the outdoors-oriented ones I use here). You’ll want to mark and save your position on the device. You can also take a picture of the latitude and longitude if it’s easier. You’ll need the position later. Don’t forget to check your GPS accuracy on the device as well (how you do it will vary based on the device).
5 - Verify the New Location at Home
When you get back to a desktop machine, bring up Google Maps and the dropped pin that you saved. I saved mine to the starred places, so it’s easy to find.
Then type in the latitude and longitude into Google Maps. It will give you the point on the map.
Then you can compare the position from the second GPS unit to your smartphone postion (the starred location), and then compare to the current location marker on Google Maps.
6 - Suggest an Edit at the New Location
If your two markers look more accurate than the current location marker, you can suggest an edit and move the marker to where you think it should be based on your location fixes.
Bonus - More Accuracy
Because I’m a freak, I generally travel with a few GPS units. If I notice a discrepancy, I take a fix from all of them and use all the positions to determine the (new) correct location. Generally when you take three or more positions on different units, you’ll be able to see a more precise cluster.
