While many towns are willing to comply with regulations to allow small cell and macro site development, many do not have access to the required technologies to perform the site selection themselves. These towns must defer the analysis to the cell phone companies. Recently, the small town of Paxton in Central Massachusetts approached Clark Labs to assist them in doing their own analysis for a cell tower location after a carrier expressed the desire to expand its services.
Clark presented their “viewshed” approach to provide the town with clear options. A viewshed analysis is done by predetermining view sights and running an analysis that outputs a Boolean (binary) image where a pixel is either in view or not in view based on the topography, the starting point and its height. Using the entire town as the source image, every pixel is evaluated for the proportion that the rest of the town, i.e., every other pixel, is in view.
The company also created a land use map and adjusted certain heights based on the land use categories. Since cell phone technology is affected by line-of-sight, the elevation in forest cover and residential areas was increased to account for the tree canopies and roof lines.
They then classified the scene into four relevant land use categories: open, forest, residential and ponds. The next step was to assign new uniform heights of 50 feet for forest and 30 feet for residential areas to selectively raise the elevations on the elevation model. Additional input required Clark to incorporate the criteria for the site selection such as requiring all tower installations must be on town property and that any proposed site be at least 100 feet from residential areas.
September 30, 2019