User:Pw271

From OpenStreetMap Wiki
Jump to: navigation, search

"Maine E911" is an import of The Maine E911 dataset which is of type jeojson covering all of Maine, USA. The import is currently (as of March 2018) at the planning stage.

Import Data

Background

http://www.maine.gov/megis/catalog/

https://gis2.maine.gov/arcgis/rest/services/Location/Maine_E911_Addresses_Roads_PSAP/MapServer

OSM Data Files

TODO

Import Type

This should be a one time import.

Identify what method will be used for entering the imported data into the OSM database - e.g. API, JOSM, upload.py, etc.

Data Preparation

Data Reduction & Simplification

Describe your plans, if any, to reduce the amount of data you'll need to import.

Examples of this include removing information that is already contained in OSM or simplifying shapefiles.

Tagging Plans

Describe your plan for mapping source attributes to OSM tags.

Changeset Tags

Describe how you'll use changeset tags in the import.

Data Transformation

Describe the transformations you'll need to conduct, the tools you're using, and any specific configurations or code that will be used in the transformation.

Data Transformation Results

Post a link to your OSM XML files.

Data Merge Workflow

Team Approach

Describe if you'll be doing this solo or as a team.

References

List all factors that will be evaluated in the import.

Workflow

Detail the steps you'll take during the actual import.

Information to include:

  • Step by step instructions
  • Changeset size policy
  • Revert plans

Conflation

Identify your approach to conflation here.

QA

The E911 data was compared to the OpenStreetMap data for the state of Maine. Of the 668671 buildings listed in the E911 database, 2547 matched street name, address number, and city. This is such a small number, since there are only 3449 buildings in Maine in OpenStreetMap that have complete addresses. For each of the matched buildings I calculated the distance between the coordinates from the 2 databases. Ideally, the distance would be zero for each building. I did this to quantify the quality of the data in the E911 database.

Here is a cumulative plot of the distances for each of the 2547 matched buildings:

Comparison of OSM date and Maine E911 data

The graph shows approximately 20% of the buildings are closer than 10 feet and 80% of the buildings are closer than 100 feet. I tried to analyze the worst 3 points (greater than 2800 feet in separation) and came to the conclusion that the E911 data was correct and the OpenStreetMap data was in error.

My conclusion is that the E911 data is of good quality.