Changeset: 121369473
added library extension and footpaths/steps
Closed by spacedman
Tags
changesets_count | 97 |
---|---|
created_by | iD 2.20.4 |
host | https://www.openstreetmap.org/edit |
imagery_used | Maxar Premium Imagery |
locale | en-GB |
source | survey;local knowledge;streetlevel imagery |
warnings:crossing_ways:highway-highway | 1 |
Discussion
-
Comment from gurglypipe
Do the steps cross over the top of each other (and the footpath) with a bridge?
-
Comment from spacedman
Its like a mini spiral staircase in 3 straight parts. From the Library Ave path you walk between the wall and the stairs, then turn 180 up the first flight, then left, left, left, over where you just came and that gets you to the upper level next to the W wall of the library. Pic here; https://twitter.com/geospacedman/status/1528823007241699329?s=20&t=oidCr7DBjzNRGAvsfyYmlQ
-
Comment from spacedman
So maybe I've not got the levels right.
-
Comment from gurglypipe
I’ve made part of it a bridge in https://www.openstreetmap.org/changeset/121388109. Does that look more correct? Feel free to edit it further if I’ve misinterpreted the photo :)
-
Comment from gurglypipe
Regarding your other tweets about building positions on OSM recently, are you aware of the OSMUK Cadastral Parcels layer? If you do, please ignore the rest of this comment :)
If not, see https://osmuk.org/cadastral-parcels/ before you think about starting to realign buildings.
Basically the satellite imagery is not guaranteed to be perfectly aligned to any source of ground truth. In particular, the alignment can change when the imagery is updated, or across different parts of the country, by up to about 5m.
Previously there wasn’t a solution for this in OSM apart from taking accurate GPS traces and aligning to those. Now there’s the OSMUK Cadastral Parcels layer, which uses surveyed property boundary data from the government as a source of ground truth.
So before you start realigning buildings, please enable the cadastral parcels layer and align your satellite imagery to it.
That’s a little tricky in the uni as it’s one big land parcel, but it’s possible to align using the houses on Five Ashes Lane. It’s generally best to check alignment in a few places, as not all parcels are perfectly surveyed.
Sorry for the long-winded comment (which you probably knew all about already). I just wanted to double-check you were aware of it before you potentially embarked on a big spree of realigning buildings! :)
-
Comment from gurglypipe
Although the thing about the Ruskin library in particular might just be a parallax error on the satellite imagery: often the imagery is actually from planes or drones, and parallax is noticeable on taller buildings.
-
Comment from spacedman
Bridge looks great and gives the correct impression on the resulting map. The Ruskin library should line up with the road/path to its E/W - next time on campus I'll check and see how it relates to green areas.
Ways (9)
- 1062930683, v1
- 1062930684, v1
- 1062930685, v1
- 1062930686, v1
- 1062930687, v1
- 1062930688, v1
- 101274501, v3
- 153342976, v6
153342972, v2
Nodes (1-20 of 21)
- 1
- 2
Welcome to OpenStreetMap!
OpenStreetMap is a map of the world, created by people like you and free to use under an open license.
Hosting is supported by Fastly, OSMF corporate members, and other partners.
https://openstreetmap.org/copyright | https://openstreetmap.org |
Copyright OpenStreetMap and contributors, under an open license |