3D Lidar Viewer

Methods


The data processing described below was done by Esri using ArcGIS Pro 2.4. See Glossary if you get lost in acronyms.

Extract Building Footprints from Lidar

1. Prepare Lidar
  • Download 2016 Lidar from CT ECO
  • Create LAS Dataset
2. Extract Building Footprints from Lidar

Use the LAS Dataset in the Classify Las Building Tool in ArcGIS Pro 2.4.

Colorize Lidar

Colorizing the Lidar points means that each point in the point cloud is given a color based on the imagery color value at that exact location.

1. Prepare Imagery
  • Acquire 2018 NAIP tif tiles from UConn (originally from USDA NRCS).
  • Create mosaic dataset of the NAIP imagery.
2. Prepare and Analyze Lidar Points
  1. Change the coordinate system of each of the lidar tiles to the Projected Coordinate System CT NAD 83 (2011) Feet (EPSG 6434). This is because the downloaded tiles come in to ArcGIS as a Custom Projection which cannot be published as a Point Cloud Scene Layer Package.
  2. Convert Lidar to zlas format and rearrange.
  3. Create LAS Datasets of the lidar tiles.
  4. Colorize Lidar using the Colorize LAS tool in ArcGIS Pro.
  5. Create a new LAS dataset with a division of Eastern half and Western half due to size limitation of 500GB per scene layer package.
  6. Create scene layer packages (.slpk) using Create Cloud Point Scene Layer Package.
  7. Load package to ArcGIS Online using Share Package.
  8. Publish on ArcGIS.com and delete the scene layer package to save storage cost.

 

Glossary

CT ECO - Connecticut Environmental Conditions Online website where you are now.

EPSG - a code determined by the EPSG Geodetic Parameter Dataset. It is a way to catalog coordinate systems because there are SO many and it can quickly get confusing.

FIPS - (Federal Information Processing Series). Numeric codes that represent US States and Counties.

LAS - the most common format for exchanging GIS point clouds . LAS is short for Lidar Data Exchange File.

LASZ - or LAZ is a compressed (think zipped) LAS file.

Lidar - is a detection system that uses light for a laser to measure distance and therefore elevation when used on an aerial platform.

NAD - (North American Datum). A geodetic datum is an abstract coordinate system with a reference surface that serves to provide known locations.

NAIP - (National Agriculture Imagery Program). A United State Department of Agriculture (USDA) program to acquire aerial imagery during the growing season.

NRCS - (Natural Resource Conservation Service). An Agency of the United State Department. of Agriculture (USDA) that provides farmers and ranchers financial and technical assistance.

Tif - a format used for imagery

USDA - United States Department of Agriculture