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tasmanet

Downloading Large Areas of Aerial Photographs

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Hi Peter,On your specified webpage, you could zoom in your target image window to a decent level of detail, then right click the resulting image and choose "Save Image As" in FireFox or "Save Picture As" in Internet Explorer to save the jpeg to disk. Remember to either set your bitmap editor to non-compressed and/or non-lossy jpeg format, or export a copy to another format (ex. BMP or TIF) to avoid degradation of the jpeg due to losses each time you save your downloaded original and work files.I have spent vast amounts of time struggling to paste photos together with variable results until I read about a fabulous freeware program called "USAPhotoMaps"; it allows downloading and exporting pre-assembled and geo-referenced big jpeg files. (I have no affiliation, just an appreciative user)."USAPhotoMaps" is available at jdmcox.com, and will allow downloading B&W and color images, elevation overlay info, national landmarks, and "go to populated place by state" info etc. from terraserver and other US governmental public domain servers which have some (but not complete) coverage of the US.The color photo databases USAPhotoMaps is accessing do not seem to have as extensive of a coverage as that from digital globe/keyhole a.k.a. "GoogleEarth", but seems to zoom in to 0.25 pixel/meter resolution in the color photos of areas I have queried with this program; I believe these are higher resolution than most if not all of those I have seen using GoogleEarth, although the latter is a truly awesome way of viewing areas we might wish to see in various ways when making scenery or taking a different kind of "simulated flight".Depending on the area you are interested in, properly tweaked GoogleEarth images may look sharpest at 1300 feet or 2600 feet elevation, and when viewed full frame using the "F-11" key, they may be saved to a jpeg via the File>Save Image pull-down menu. These bigger jpegs would probably require only a modest amount of work assembling an airport sized area; probably a lot of work would be involved in putting together a large photorealistic region from arbitrarily named bitmap files though!. Unfortunately, there are no color photos yet available via the USAPhotoMaps databases accessed for the Johnson County, KS Industrial Airport you appear to be interested in; the quality of the images on that server appear promising though! Please note that my test showed a somewhat lower resolution jpeg written during the download from that site than the one I got from saving a zoomed-in GoogleEarth full frame "F-11" window saved jpeg file.I share your concerns about having to laboriously paste together color screen grabs from GoogleEarth or AirPhotoUSA windows in order to get coverage of areas not available (yet) in USAPhotoMaps, and would welcome additional ideas from other users on how to do this easier (only for un-distributed non-commercial reference use on one's own machine of course!). I hope that there may be a program out there which can do this assembly semi-automatically or even automatically if you save your jpeg images downloaded with programs other than USAPhotoMaps with specific sequential and/or georeferenced filenames; ...anybody know of such a freeware program program, or of such a feature in an "affordable" mainstream commercial graphics program?.Last but not least, remember that any images you use must preferably be "orthorectified" (...not a medical procedure!:-lol) originals (ex: DOQQ), and must then be re-projected to the WGS84 datum specified in Microsoft's Terrain Tools SDK for the "UTM zone number" on the globe that your area of interest is located in if you were considering using them for FS2002/2004 as either a bitmap background template for default data/texture-based scenery making, or perhaps as a "personal use only" photorealistic tile array scenery.There are many links I have seen in the AVSIM forums which explain how to use free programs to re-project and otherwise use photos in the FS scenery making process. I would particularly search for those posts by Dick Ludowise ("Rhumbaflappy"), Bob Bernstein, Holger Sandmann, Jim Keir, "LuisFelizTirado", "LuisSa" and "Slacktide" to name just a few of the many generous forum participants as rather well-experienced gurus for FS terrain and scenery imagery processing.Here's a couple of especially informative related links for starters:http://forums.avsim.net/dcboard.php?az=sho...23433&mode=fullhttp://forums.avsim.net/dcboard.php?az=sho...ing_type=searchGood Luck!GaryGB

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I've played around with Google Earth doing manual geo-referencing of images. One thing I haven't tried, but might be worth considering is that GE allows overlay of shapefiles. You could create a shapefile of a lat/long grid and upload it. It will be burned into the image, but after saving it you could crop along the grid and have the data for constructing a world file for the images. A couple different grids, with overlap, would allow for mosaicing the images.scot s..

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From another forum In order to get the proper Google Earth Zoom level 4.8 m/pix ( Altitude above earth), do the following:- In Google Earth, set to NORTH (N Button in navigation)- Zoom out to an altitude of approx 20,000 ft.- F11 Full screen the Google Earth- Draw a distance line, horizontal, with the following length in meters:(Your horizontal screen resolution)*4.8- Zoom in and pan around Google Earth so that ends of the line are as close to the edges of your screen as possible. Use ALT + and ALT - for very fine zoom adjustments.When the edges of the line are touching edges of the screen, read off the altitude. That's it - that's your altitude, at which you must take ALL of your imagery screenshots. I use a 1280x1024 screen resolution, so the screen is 1280 pixels wide (horizontal res). There fore, according to the above calc, the line I need to draw is 6144 METERS long, and the Google Earth altitude at which I will observe this resolution is 17966 ft.Check that with your numbers.Misho Katulic, authorTerraBuilder

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