Letters from the SAL: Urban Tree Canopy Assessment - Rockville, MD:
The video below presents the results of the urban tree canopy (UTC) assessment we just completed for Rockville, MD. High resolution land cover is the basis for the UTC assessment. Rockville is covered by both leaf-on color infrared imagery and LiDAR data, but mapping land cover proved to considerably more challenging than we expected. Some filtering was performed on the LiDAR data, resulting in a very inconsistent first return dataset (we did not have access to the point cloud). By taking a data fusion approch, combining the LiDAR and imagery in Definiens we were able to get around this, but it was not easy. I discuss these issues a bit in the video, but hope to cover the process in more detail in a future post. Imagery was prepped using ERDAS IMAGINE. LiDAR data was prepped using QT Modeler. The UTC metrics are generated using a geoprocessing model within ArcGIS. Please click on the image below to view the video.