Terrain offset

[mugwort]

Hi,

Similar to the blender OSM plugin, there is a large satellite offset when mapping to the terrain.

This is more crucial in JOSM since users are using it to edit OSM items incorrectly!

Please respond to my email and I will forward the thread to the blender OSM plugin dev which demonstrates this offset which I have found to be up to 1.3metres and the script i have developed to correct it to with 5cm!

All the best,
Tony

[simon04]

Thanks for your report, however your ticket is incomplete and therefore not helpful in its current form.

Please add all needed information according to this list:

• The required parts of the Status Report from your JOSM.
  • Please, use Report Bug from Help menu and copy & paste.
• Describe what behaviour you expected.
• Describe what did happen instead.
• Describe if and how the issue is reproducible.
• Add any relevant information like error messages or screenshots.

To ensure that all technical relevant information is contained, create new tickets by clicking in JOSMs Main Menu on Help → Report Bug.

[Don-vip]

What are you talking about?

[simon04]

Please see comment:1, we require a status report in order to look into and fix issues. A 10 pages PDF document is no status report.

[Don-vip]

If it's only about imagery offset, there are a ton of existing features to warn about offsets, share offsets, etc. It's up to users to check if their imagery is correctly aligned using other sources, nothing new. And we don't have time to read 10-pages PDF for each ticket to understand what is being asked for.

[mugwort]

Replying to Don-vip:

If it's only about imagery offset, there are a ton of existing features to warn about offsets, share offsets, etc. It's up to users to check if their imagery is correctly aligned using other sources, nothing new. And we don't have time to read 10-pages PDF for each ticket to understand what is being asked for.

Thanks for the reply.

What I can't understand is why, if GPS tracks are considered more accurate than imagery, why is the web OpenStreetMap editor (including it's lovely tutorial) based on tracing buildings from the Bing Aerial Imagery overlay, when this source is warned to be offset in JOSM?

Specifically, my area of interest is the Spring Lane Building on Heslington Campus, York, UK.

It seems for each image overlay I select, the building is offset by a different amount and direction, despite being the correct shape. Thus I assume it must have been traced and then aligned using some GPS tracks.

Is it really not possible to find an image overlay (or suggest a correction to the server), such that there's agreement (between OSM & the image provider) as to where the building is placed?

Or is the defnition of the Spring Lane Building ​https://www.openstreetmap.org/edit#map=18/53.94769/-1.05064 really over a metre out of place as shown on openstreetmap.org ?

Thanks again,
Tony

[skyper]

Do not think this is the best place to discuss imagery offsets but unless you use a Geo-referenced background you will have offsets even within one tile.
There are imagery offset databases (plugin) to share offsets but depending of available sources one meter might be hard to distinguish and especially close to buildings, I doubt, that your GPS unit or even the average is accurate enough to tell the correct position.