Have been working on developing building footprints from aerial imagery and LiDAR data that required an NDVI calculation and wanted to share the best workflow that I have found. You can read more about what a Normlized Difference Vegetation Index (NDVI) is here.
Color aerial photo (left) and NDVI calculation (right). Notice how roofs, roads and vegetation are well defined in the NDVI image.
I am excited to announce that I have been asked to join LiDAR News as a Distinguished Contributor.
LiDAR News is one of the largest information points for laser scanning on the internet and the only dedicated laser scanning print publication. I was asked to begin contributing content a few weeks ago and had my first article published online yesterday. The article will also be published in the LiDAR News print publication next month.
This is a map of the planned Best Buy store closings in 2012.
Map of attainable bandwidth
Today bandwidth is King.
An increasing number of services ride on the all-encompassing internet connection. This has done three things to the rural telecommunication business:
"The Point," BHI, NC
I was approached by a resident of Bald Head Island, North Carolina (BHI) and questioned about the different dune ridges that span the island, and in particular the dune ridge than runs beneath their house. So I mapped the island to determine the location of the dune ridge and possibly shine some light on their history. I have a background in Geomorphology (the study of how landscapes change), so I also provided some information regarding the processes that have worked (and are still working) to shape BHI.
LIDAR derived 3D estimation of tree height.
I put together a poster advertisement, displaying a few of the analyses I could do for practicing foresters in the region. Forestry is inherently geographic, so it wasn't difficult to "dream-up" some examples. Some of the examples are basic (imagery) while others are more advanced (tree height, visualizations).
Cell Coverage in the United States.
High resolution cell coverage data is envied by businesses all over the country. Unfortunately, providers and cell tower owners keep a tight leash on cell coverage information.
Recently, I was asked by a telecom company to produce a cell coverage base map where they could overlay their assets and customers; helping them to quantify their need for, and best locations of new cell tower construction within their service area.
Photo: Tammy Pelletier, WA State Dept of Ecology
Water waves are formed by wind blowing over the surface of water. Wave height is dependent on: Wind speed, fetch (distance of water on which it is blowing), wind duration and water depth. In coastal bodies of water, wind waves, especially those associated with storms, can be unpredictable and pose hazards for recreational persons on the water in the short term and present long term erosional hazards to developed areas along the coast.
Wemo is GIS tools which uses wind, depth and fetch data to map wave height potential in areas of contained water (i.e. lakes, bays, creeks). Wemo’s output can be used to assess shoreline erosion potential, and predict areas of dangerous wave heights during specific storm conditions.
Houses near Nags Head, NC
Currently, the Outer Banks is witnessing significant rates of beach erosion, most of which is a function of sea level rise. In opposition to popular reporting, sea level rise and fall are a natural phenomenon which have been continuing for millennia. Currently we are in a period of sea level rise (Riggs and Ames 2003), the rate of which (most scientist agree) has been increased by human influenced global climate change (Gornitz et al. 1982). On the Outer Banks the effects of sea level rise are compounded by land subsidence from glacial isostatic adjustment. In fact, due to the local influence of land subsidence the Outer Banks could be experiencing a 60% greater rate of relative sea level rise in comparison to the national average of the United States (Cabanes et al. 2001).
In March, 2011, I traveled to the Pea Island national wildlife refuge to terrestrial laser survey a section of overwashed dune in an attempt to establish a long term overwash monitoring site within the Cape Hatteras National Seashore. As I have detailed previously, overwash is an important aspect of barrier island landward migration and thus an important area of research along the Outer Banks, which is a barrier island. This is especially true if you also consider the amount state owned infrastructure and privately owned houses which are currently impacted or have the potential to be soon impacted by barrier island landward migration.
I placed first in the RENCI Visualization Challenge held at East Carolina University on March, 29, 2011. Each participant was challenged to make the best use of the Vis-wall during a ten minute presentation to an audience of faculty and students. The Vis-wall provides a unique environment for displaying content and consists of a rear projected display at the resolution of 4200 x 1400. My presentation introduced terrestrial laser scanning to the audience and provided them with a visualization of the Brewster building.
I chose the Brewster building since the contest was being held within the building. This allowed the audience a better conceptual environment from which to understand terrestrial laser scanning technology, whereas if I had chosen any other laser scanned dataset, the audience may not have completely comprehended the abilities and methods of laser scanning. As part of the presentation I made an animation fly-through of the Brewster building model and point cloud data at a widescreen resolution appropriate to the resolution and aspect ratio of the Vis-wall. I have uploaded the video below, however in a resolution and proportion which is easier to view at standard aspect ratios found on most PC's and laptops.