How To Adjust PGS to EVS Precision: An Example and Thoughts
PGS to EVS Precision
Here is another example of PGS to EVS Precision. The map scale is 1:15,000. At 1:62,500 the PGS tracks the Vietnamese coastline. At 1:15,000 the PGS does not track the coastline. It "sharp-turns" it's way up the coast. The adjustment of the PGS vectors into EVS precision was literally done in seconds. This short segment took less than 1-minute to adjust. I repeat, EVS tracks the coastline much more precisely then PGS is able to do.
A trained, experienced human operator makes digitizing decisions and evaluations quickly, consistently and accurately. The use of automated digitizing programs work, to a point. It appears that they do not place vectors on the imaged shoreline as consistently as humans are able.
I am not bashing PGS. I think it is superb compared to WVS shorelines. It is an excellent vector shoreline product. However, it needs to be finished. PGS should be completed to the EVS level of precision. It takes a plan of operation and the means to execute that plan. I believe that PGS can be adjusted to EVS precison within 12-months and, I am certain, at a fraction of the cost of the original effort.
First some facts about the magnitude of the effort. Out of 881 Landsat ETM+ 2000 mosaics, 631 contain shorelines. These mosaics would constitute the base imagery for this project. Out of the 631 mosaics, 41% (258) are primarily islands with little or no continental shoreline. These images would be relatively fast to complete. Often they contain only a single island. 32% (199) contain shorelines and islands. These images would be the most demanding. A single volunteer might spend 2-months on one of these mosaics. For example, Southeast Asia contains a number of these and the shorelines depicted are numerous and quite challenging. Finally, 28% (174) contain primarily shorelines. These will be fairly fast to digitize. Most of these shorelines are uncomplicated and are imaged with few shoreline obscuring clouds.
It is my belief that 100 worldwide volunteers could be selected, trained and supplied with the tools necessary to complete their assigned Landsat ETM+ mosaic(s). They would have a 2-fold reward. First, quality training and experience in compiling a product that will endure for years. Second, they would receive, for their efforts, the software and hardware they compiled their portion of the project with.
As work is completed, zipped packets would be sent to a Quality Control team, made up of professional/experienced mappers, that will ensure the finished work satisfies the EVS Project's rigorous expectations. Once completed and QC'd, packets will be assembled into a finished Enhanced Vector Shoreline product.
Each volunteer will require software to digitize with and a computer to work on. These tools will be donated and passed on to the volunteer upon completion of their phase of the project. The companies that make these critical donations will be rewarded tax-wise (deductions) and exposure-wise (they helped to build the preeminent world shoreline map). I am certain other benefits will come to those who sponser this vital effort.
This project can happen for about $100,000, plus donations of software and hardware. I know that some of you can benefit immensely from the EVS product. Others can derive benefits from the layers of information that will be added to this new shoreline.
Am I the only one that believes this effort needs to happen? I am convinced that one of my readers is the person that can make this project a reality! I will keep offering until the right person responds.
