Map bkgnd coordinates

[Guest Robi]

I'm trying to load a background map into FSSC and Ground2k.I start with fssc first and after take NW and SE Lat and Lon from fssc i load the same map in ground2k with the same coordinates of fscc.Later i go to compare one point but in the two map it isn't on the same place. I get some difference in coordinates.Now i don't know what of two program give me the right position.Can help me to understand the problem????I hope can understand me but my english is not good

[rhumbaflappy 113]

Hi Robi.Ground2K requires background images in Geographic projection ( equiangular ). I believe FSSC requires background images in Orthographic projection ( equidistant, measured in meters ). They are NOT compatible.Almost all downloadable aerial images, topo maps, and online map-service images ( such as Mappoint.com ) are Orthographic, and compatible with FSSC.Almost all GIS derived data ( such as Terrascene images made from Digital Chart of the World data, or TIGER data for the USA ), are Geographic in nature. TMFViewer screenshots are Geographic. These are compatible with Ground2K.You should be able to use SHP data screenshots of images for Ground2K from a variety of programs. Terrascene, Map Maker, Global Mapper, ArcExplorer2....The only good news here is that Mappoint.com images are mostly based on Digital Chart of the World... so they could be used for FSSC with good accuracy; Terrascene, or ArcExplorer2 images can be constructed of the same area for Ground2K, with good accuracy. So you can have 2 sources for decent maps for use with the programs.===============To my knowledge, there is no freeware raster-reprojection utility, to convert from Orthographic ( distance-based ) to Geographic ( angular-based ). I'm not sure if Microdem will do this... maybe someone else could confirm that.Payware will cost a minimum of about $200 US. For about $250, you could get Manifold, then all your problems would be over concerning data manipulation for landclass, mesh, Ground2K images, or FSSC images. Justin Tyme, of FSgenesis uses this program. I have not used it... I have access to Global Mapper to convert images, but that costs about $180 US, and is nowhere as useful as Manifold.===============I have been studying reprojection, and hope to have more info on this in the future.FSSC appears to allow the entry of lat-long points for image positioning... but if you enter them, then re-check the entry later, you'll find FSSC may have changed your entry points! This is because Derek's formula for positioning doesn't reproject the image... it just tries to make sense of the positioning of the image ( and it can't for a Geographically projected image ). You need to reproject the image yourself to Orthographic... then you can use it in FSSC.Similarly, aerial image mosaics of large areas cannot be used accurately with TerraBuilder ( using resample to make CUSTOM ground-tiles ). Resample needs Geographic projection, and the aerial images are Orthographic. They are NOT compatible, and lead to errors.Terrascene derived images WILL be accurate when used with TerraBuilder, because those derived images are Geographic in nature.Aerial mosaics will NOT work accurately for Ground2K, either.:(Dick

[Guest gorchi]

Hi,I just wantted to add, that FSSC seems to have some problems with background maps and scaling the pictures. I found out this when I was drawing roads around Slovenia and I used maps from Atlas of Slovenia. In one place, I took 2 bitmaps from Atlas, one was le't say 30km wide, while the other was 60km wide. And putting them together, on the top, both were jpg and both had scale of 8.0, the difference was couple of 10 meters. So the best way to align those maps correctly is to put some odd objects, like chimney or so and then align maps, screenshots etc. using these temporary objects.Best regards,Goran BrumenFS Slovenija 2002 teamhttp://slovenia.avsim.net

[Guest Robi]

Thank you very much boys...I think that i'll use fssc with my road map since i don't need an absolute precision for my own scenery (my little town) and into fssc the distance from one point and other is enough good.I hope to do the right thing...However I think to have clarified my doubts ...Best regardsRobi

[Guest gorchi]

Robi,I draw my roads using FSSC and then used SCM2VTP to convert road to new FS2002 style. After then I deleted original roads.Best regards,Goran BrumenFS Slovenija 2002 teamhttp://slovenia.avsim.net

[Guest Robi]

Hi Goran can you tell me in a few words how to use SCM2VTP ?Thank Ciao....