Bend building import

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About

The city of Bend, Oregon has offered a complete building footprints layer with an OSM-acceptable license. The current building footprint layer in OSM contains about 1,100 buildings (as of 9/26/16), mostly traced by hand from satellite imagery. The building footprints file available from the city contains more than 36,000 features. In addition, building heights and addresses can be derived for each building from publicly-available data sets.

Import Plan Outline

[x] Acquire data from city

[ ] Determine OSM tags to be included

[ ] Process data

[ ] Divide data into discrete tasks

[ ] Complete import

Goals

Add an extensive building footprints layer for Bend, Oregon to OpenStreetMap with tags for addresses and building heights, and possibly building types.

Schedule

Planning meeting with interested volunteers scheduled for Oct. 6, 2016.

Ideally would like to complete this project by Jan. 1, 2017.

Import Data

Background

Building footprints shapefile: https://github.com/MaptimeBend/bend_buildings/tree/master/data

Data license: https://raw.githubusercontent.com/MaptimeBend/bend_buildings/master/data/building_footprints2004_intlfeet_disclaimer.txt

Additional data

Deschutes County open data taxlot file: http://data.deschutes.org/datasets/28019431cced49849cb4b1793b075bf1_2

Deschutes County open data assessor info (for addresses): http://data.deschutes.org/datasets/aea94004ae8c49e6a6dec394522677ad_1

Oregon DOGAMI lidar data: https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/1452/

OSM Data Files

Not yet created.

Import type

One-time import.

Data Preparation

Data Reduction and Simplification

Probably not necessary. Most buildings are basic rectangles with few points that could be removed.

The buildings shapefile contains several fields that will probably be eliminated as they are artifacts of the files CAD origins.

Tagging Plans

TBD. See https://github.com/MaptimeBend/bend_buildings/issues/1 for planning discussion.

Changeset Tags

TBD

Data Transformation

  1. Buildings acquired from city loaded into POSTGIS database (Software: psql)
  2. Taxlots acquired from county loaded into POSTGIS database (Software: psql)
  3. Assessor table (with addresses) loaded into POSTGIS database (Software: psql)
  4. Raw lidar .laz file processed to use only first returns, converted to elevation x/y/z .txt file, loaded into POSTGIS (Software: liblas, laszip, psql)
  5. Existing OSM buildings exported using Overpass Turbo, loaded into POSTGIS database (Software: Overpass Turbo, psql)
  6. Perform union of existing OSM buildings and Buildings?
    1. This is where we'll need to make some decisions and do some data-wrangling.
    2. Many existing OSM buildings might be newer than the Buildings, and should be kept
    3. However, many OSM buildings that already exist in the Buildings data are of inferior quality to the professionally-produced Buildings footprints
    4. Existing OSM buildings will have some tags that we will want to preserve
  7. Perform a join between Addresses table and Taxlots table using taxlot id (this is a one-to-one relationship). (Software: psql)
  8. Perform a spatial join between Buildings and Taxlots tables, adding specific address fields to Buildings table (Software: psql)
  9. Extract Buildings heights from Elevation table following similar steps as those outlined in this tutorial.
  10. Convert final fields from Buildings table to appropriate OSM tags.

Data Transformation Results

Data Merge Workflow

To be discussed at Oct. 6 meeting.