Sbuilder WGS84 Conversion Help Please

[Guest jimjones]

Sbuilder WGS84 Conversion Help PleaseI'm trying to make photo scenery for an area of about 400 LOD13s in standard resolution using Sbuilder.I need to break up this area into 15 smaller ones to compile separately. The resulting tiles of the areas don't align well with one another and the location of places within the areas are also off even though the corners of the areas are placed correctly in FS.After reading several posts about Sbuilder photoscenery making on AVSIM, it seems I may need to use Sbuilder conversion to convert a bitmap to WGS84 format. My source data is Terraserver which I think is UTM format.In one of Luis's posts he indicates the need for datum information which I do not have, but could be derived from formulas and data at:http://earth-info.nga.mil/datums/natodt.htmlThat link is no longer active, but it seems there are newer conversion routines at "earth-info" available using different datum formats that are not useful to Sbuilder.Where can I obtain the Sbuilder style datum information for Louisville, Kentucky USA?Is this too big a project to get accurate placement of locations within the areas if conversion to WGS84 format is accomplished?All help is appreciated.Jim Jones

[Gridley 257]

Please keep me posted on your progress here - I have had no luck. I have started to learn GDALWarp to accomplish this - there's a lite version available for free.

[Guest jimjones]

Thanks Scott for your response. I thought I would see how well the minimum of 4 LODs would match with surronding groups of 4 LODs. Not well enough since a runway was misaligned at an LOD border from one group of 4 with another. Using the 4 LOD method for a small area does provide a better placement of that area than that same area in a big project with many LODs. This is of course without the conversion to WGS84. No luck finding the data I need. It may be wishful thinking, but perhaps Luis will see this and provide some help on the WGS84 conversion issue.Good luck with GDALWrap. A brief google search led to some pretty deep looking C++ coding. That certainly leaves me out of that path of pursuit!!I really have enjoyed your Bermuda project. When I resolve the recent issue of not being able to download from AVSIM, I hope to try out your Dulles scenery.Jim Jones

[Gridley 257]

Check this link - the command line is not too bad:http://www.digitalgrove.net/image_reprojection.htm

[arno 1]

Hi Jim,I have used SBuilder in the past to reproject a few images, but I would have to check if the lastest version of SBuilder still works the same. Can you maybe indicate where you have the trouble? Is it with entering the correct settings on the conversion form or somewhere else?At work I have also used GDALWarp and I think that might even work faster, although you don't have the nice GUI of SBuilder. Of course you first need to be really sure with projection your images use and know its border coordinates (or the coordinates of a few know points).

[Guest jimjones]

Thanks for the link. Lots of interesting stuff. The dgwarp looks promising, if only all the commands were well documented. One of the included batch files, utm_jpg2latlong_tif.bat, might work for me if I knew what values to put into the source jgw file that should accompany the source jpg file.What does one do with the resulting warped file for use with Sbuilder? My guess would be to use the original bimap lat-long values for the NW and SE corners when calibrating with Sbuilder and use only the LODs that contain the the warped image, excluding the black.Are you having any success with dgwarp?Jim

[Guest jimjones]

Hi Arno,Thanks for your comments.My basic problem with Sbuilder reproject is that there does not seem to be a datum in Sbuilder for my area, and I don't know where to get the values for the parameters to build my own datum. Luis provided a link in his Sbuilder documentation where to get those parameters, but that link is no longer active.Scott has directed me to gdalwrap too. I'm trying to figure out how to use it, but there seems to be a lack of a comprehensive list of commands, their explanation, data required etc. Having a Phd in cartography might be useful. I'm low on the learning curve now. Perhaps a little more searching, reading and help from others here on the forum will bring success.Jim

[Gridley 257]

I haven't really had the time to experiment...much too busy right now with real life and our bahamas scenery projects (which is getting close!). Someone else with our group was playing with it too, but I think it's backburnered right now.We want to use GDWarp to reproject seamless' land use data which would be excellent to import into SBuilder to use with land use map to make land class automatically. That imagery is NAD83, but the biggest problem is that the metadata gives the bounding box in latitude and longitude. SBuilder will not accept lat/lon for the UTM image. I have not found a simple way to just convert the coordinates to northing/easting without also changing the projection system. I suspect that accomplishing that would solve my problem with SBuilder...

[LuisFelizTirado 33]

Hello Jim, We have amply discussed reprojection in this forum - you should be able to find a link to the complete thread (one of them, anyway!) in the Beginnner's Guide at the top of this forum:http://forums.avsim.net/dcboard.php?az=sho...ing_type=searchThe process is quite simple, the tools (ERDAS Viewfinder and a bunch of ECW utilities) are easy to use, free, and have graphic user interfaces, and the results are very convincing.Here is a picture comparing before and after (I just love showing pictures):http://forums.avsim.net/user_files/148212.jpgThat is the Naked Lady Ranch that once was a pristine wildlife haven in Florida before the bourgeois polluters moved in and built an airpark.Scott, to convert between UTM and geographic (that is, no projection), I have been using this spreadsheet here:http://www.uwgb.edu/dutchs/UsefulData/UTMConversions1.xlsand this is the gentleman's home page:http://www.uwgb.edu/dutchs/index.htmlBest regards.Luis

[LuisFelizTirado 33]

Oops, very sorry, looks like Viewfinder is no longer available from Digital Grove - you will have to search for an alternate site.Best regards.Luis

[Gridley 257]

Thanks Luis! I'll give that a try tonight...(PS - Thanks for that great post on VTP lines - really got me thinking about what to do next!)

[Guest jimjones]

Hi, Scott, Luis and Arno. Again many thanks for leading me in the right direction. I have had good success generating photo scenery for Louisville with remarkably accurate results with a test of 180 LODs. My goal was about 450 LODs, but I may expand this a bit providing there are no memory problems along the way.Scott, thanks for pointing out the DGWarp program, an adaption of GDALWarp, and Arno for confirming its value. Luis, thanks to you above all for providing Sbuilder that made all this possible in a GUI interface. And of course thanks for your last message on this subject that pointed out the lat-lon to easting-northing conversion program by Steve Dutch needed by GDWrap.My work flow went something like this: Downloaded many screens from terraserver, captured them and batch processed them with Paint Shop Pro 9.0 to extract only the the bitmap portion.(I did not know about USAPhotomaps at the time. It seems it can download large amounts of data, but I'm still uncertain if it would help.Merged these files into a larger mosaic with Paint Shop Pro (PSP), named Lou3.jpgProcessed with the DGWrap program the batch file loutest.bat containing:c:dgwarpbingdalwarp -s_srs "+proj=utm +zone=16 +datum=NAD83" -t_srs "+proj=latlong +datum=WGS84" -co INTERLEAVE=PIXEL -co TFW=YES -of GTiff c:dgwarpsource_imagesLou3.jpg c:dgwarpLou3.tifusing the source image Lou3.zip and producing a reprojected image file of Lou3.tif and using the accompanying text, Lou3.twf, file containing:10. ( 10 meters/pixel )00-10. ( 10 meters/pixel ) 596399.91 ( Northing)4242400.03 ( Easting ) Info in ( ) is a description of the data and not part of the file.I still may use a higher resolution of 4 meters/pixel. The Lou3.tif file was converted to a bmp file via PSP.The left and right edges of this file was trimmed off vertically at the borders of the leftmost and rightmost pixels that correspond with the original bitmaps.Sbuilder was used to compile the LOD tiles using this trimmed bmp file and the coordinates taken from TerraServer for the upper left and lower right pixels of the original merged bitmap.Jim Jones

[scott967 62]

If you need to convert points from different projections, I recomend the US Army Corps of Engineers GeoTrans 2.2.4.For the specific case of UTM <-> geo, there is also a good web calculator:http://www.wherearewe.co.nz/geodetics.htmlscott s..

[Gridley 257]

That looks like a very useful tool, Scott - I'll need to explore a bit, but NAD83 is not an obvious selection. Maybe something similar. I've tried to use the full USAC package, but it requires that the lat/lon pairs output to a different coordinate system, which is not what I want.THANKS!

>Hi, Scott, Luis and Arno.  >>Again many thanks for leading me in the right direction.  I>have had good success generating photo scenery for Louisville>with remarkably accurate results with a test of 180 LODs.  My>goal was about 450 LODs, but I may expand this a bit providing>there are no memory problems along the way.>>Scott, thanks for pointing out the DGWarp program, an adaption>of GDALWarp, and Arno for confirming its value. Luis, thanks>to you above all for providing Sbuilder that made all this>possible in a GUI interface. And of course thanks for your>last message on this subject that pointed out the lat-lon to>easting-northing conversion program by Steve Dutch needed by>GDWrap.>>My work flow went something like this:  >>Downloaded many screens from terraserver, captured them and>batch processed them with Paint Shop Pro 9.0 to extract only>the the bitmap portion.>>(I did not know about USAPhotomaps at the time. It seems it>can download large amounts of data, but I'm still uncertain if>it would help.>>Merged these files into a larger mosaic with Paint Shop Pro>(PSP), named Lou3.jpg>>Processed with the DGWrap program the batch file loutest.bat>containing:>>c:dgwarpbingdalwarp -s_srs "+proj=utm +zone=16>+datum=NAD83" -t_srs "+proj=latlong +datum=WGS84" -co>INTERLEAVE=PIXEL -co TFW=YES -of GTiff>c:dgwarpsource_imagesLou3.jpg c:dgwarpLou3.tif>>using the source image Lou3.zip and producing a reprojected>image file of Lou3.tif >>and using the accompanying text, Lou3.twf, file containing:>>10.		( 10 meters/pixel )>0>0>-10.	   ( 10 meters/pixel ) >596399.91  ( Northing)>4242400.03 ( Easting )> >Info in ( ) is a description of the data and not part of the>file.>>I still may use a higher resolution of 4 meters/pixel. >>The Lou3.tif file was converted to a bmp file via PSP.>>The left and right edges of this file was trimmed off>vertically at the borders of the leftmost and rightmost pixels>that correspond with the original bitmaps.>>Sbuilder was used to compile the LOD tiles using this trimmed>bmp file and the coordinates taken from TerraServer for the>upper left and lower right pixels of the original merged>bitmap.>>Jim Jones

You should also look into the BigJPG function of USAPhotoMaps - it will be a BIG help for you!