Fs2004 Srtm Global Terrain Map Of Africa
I have changed the title of the blog as I am moving the focus away from CFS3. I still have a long term project in mind for CFS3. However as I have mentioned in previous blogs, water body data matching coastlines is a bit of a problem with higher resolution terrain mesh. Presently the only solution is hand editing water body data.
Editorial Whilst always a fan of the work carried out by Microsoft, FSX had some pretty average meshing. Thankfully, the community has always found good ways.
As to CFS3 it may be best to use lower resolution mesh. That will be determined by experimentation. MAW looks as if it used SRTM 30 or early SRTM 90M interpolated with GTOPO30 dem data.
The islands are much smoother than SRTM 90M v3, as are the coasts. Thus mesh at a lower resolution may work a little better. Anyway I have started a Europe2 project for CFS3 with a rough timetable of approximately one year. I have already created a mesh sans water bodies, land class and vector data. It is slightly larger, about the same size as MAW, and a little bit further north of the current ETO theatre and will accommodate mainland Britain and Denmark, plus little bits of Norway & Sweden (no Orkney Islands unfortunately).
Any water body editing that I do will be useful in other projects in the world of GIS. Not necessarily flight simulations. A couple of hours every other day is planned for coastline editing. I have other simulations in mind in addition to or instead of CFS3. In the meantime personal circumstances take precedence. When I discover something of note or have something to show I will post.
But I anticipate posts will be somewhat haphazard. I am in quite a bit of pain with cancer which is affecting my ability to sit at a computer at present. One thing about being virtually the only person presently 'dabbling' in CFS3 terrain creation is the frustration I experience in getting others to apprehend exactly how the terrain system works. Firstly having participated in the ETO expansion project there was a misconception that the mesh is incorrect or problematic. Actually the SRTM terrain mesh was probably the only geographically correct data in the project.
SRTM 90m version 3 finished data, was downloaded from CGIAR. This data was derived the Shuttle Radar Topography Mission, an 11 day shuttle mission in 2000. The only problems that can occur with this data are voids or the occasional spike.
However as CGIAR's data is version 3, these problems have been largely corrected. Global mapper was used to compile the relevant SRTM files into one large DEM file for the ETO geographic area. Global Mapper is limited in it's terrain editing abilities. One can flatten certain areas by creating a vector polygon and assigning an altitude to it.
This is useful for getting rid of features such as breakwaters etc., that may not have existed during WW2 or perhaps creating ones that did. There were a number of negative elevations in the SRTM data for the ETO area, for below sea level areas. I did change minimum elevation to 0 metres in the master DEM as the CFS3 SDK tools calculate all mesh elevations in the final CFS3 mesh between 0 and the maximum elevation specified on the command line input. Apart from that there was little adjustment to carry out.
This must include any costs to buy water rights and to transport the water to the plants, as well as the cost to treat the circulating cooling water and to dispose of the cooling tower residues. This is called wet cooling, or evaporative cooling. We are concerned here with these two methods of cooling or their use in combination, termed wet/dry cooling. The economic decision of whether to use wet or dry cooling, or a combination, at any given point of cooling in the plant depends on the true cost of water. The economics must be calculated for each type of cooling load in the plant.
I did carry out a number of experiments in scaling the elevations in the mesh slightly and also experimented by flattening the terrain mesh under the water bodies to make the terrain match the mesh in certain area. However the result was very artificial looking and not proceeded with. The DEM meshes were exported from Global Mapper as a large *.bil file.
When exporting a series of SRTM dem tiles into a single large DEM in GM I find it is best to leave interpolate unchecked in the export options. Leaving this checked causes seams and ridges in CFS3. This is about the only thing that could possibly go wrong. The the end result was virtually an un modified SRTM V3 90M mesh, processed in accordance with CFS3 terrain SDK guidelines. Once decisions have been made it takes my computer approximately 6 hours to compile a terrain mesh, apart from experiments there is very little else to do. Apart from experimentation, and computer time compiling a very easy task.