Texas LIDAR Import
The Texas Natural Resources Information System (TNRIS), the state of Texas' main agency that collects GIS data, recently began offering LIDAR data for download to the public. This project will generate building footprints from this data and import them into OpenStreetMap. Given the intense processing needed, this project will be a long-term, on-going process.
TNRIS has released its LIDAR data into the public domain with a Creative Commons CC0 license, making it compatible for import into OpenStreetMap.
According to TNRIS coverage areas, over 85,160 square miles of LIDAR is available with a resolution <1 meter. Highest quality data (i.e. LIDAR captures at 1m or less, with building classifications that have been through QA/QC testing) will be imported first, in the following order:
- County seats
- Major rural cities and town centers
- Outlying rural areas along the coast of the Gulf of Mexico
- Remaining areas
- A fishnet will be created to allow the import to be managed in a tasking manager
- Building footprints will be drawn from LIDAR data for a quarter quadrangle, adjusting settings as needed to ensure quality footprints.
- Resulting footprints will be processed using the Extract Roof Forms for Municipal Development workflow developed by ESRI. This will provide the footprints with heights, roof forms, and roof height data to enable 3D mapping.
- Where possible, footprints will be spatially joined with compatible County Appraisal data to categorize each building with appropriate tags. A parcel's state code can be used to provide basic tagging of houses (A1), commercial buildings (F1), industrial buildings (F2), etc.
- Footprints will be reprojected to the standard WGS84 CRS
- Footprints will be imported with JOSM, verified against the Texas Orthophoto Layer and validated with the JOSM validator.