FSX How do I Determine Unknown Coordinates in SbuilderX

#1
Hi,
While waiting to get the aerial view of KBHM from 1970 to align with other Geo-Reference images, I guess you can call it, I've been working on the ground terrain for the Alabama Mega Scenery Earth around the airport. Unfortunately, I could not find a bitmap and all the images are bgl files. I didn't know if it's possible to convert a blg file to a bitmap so I had to get the image from a top down view screen shot from inside FS and export it into Gimp. What I've done is cloned out everything that did not exist in 1970 and shortened the runways, otherwise they'll show up in the sim. I have it completed and I opened SbuilderX to compile the image. I selected File-Load from disk, and a box pops up saying that I may need to calibrate it, since the image did not come directly from the SbuilderX background image. Now the problem is that I do not know what the 4 coordinate positions are so that I can calibrate it. Is there any way to determine the unknown coordinates of the 4 corners of an image that was modified?

Ken.
 
#2
Hi Ken:

Please explain what you mean by: "ground terrain for the Alabama Mega Scenery Earth around the (KBHM) airport".


Also, please explain what you mean by: "I could not find a bitmap and all the images are bgl files".

IIRC, we already identified the same or equivalent free online (color) imagery sources used in Alabama Mega Scenery Earth.

Those imagery sources can be downloaded either directly by SBuilderX, or they can be downloaded from a online web portal such as EarthExplorer or USGS National Map via a web browser, re-projected in a GIS application, and then loaded into SBuilderX via the Add Map > From Disk method. :pushpin:

Please explain what type of scenery you are trying to create at this time, and which FS utility you are using for each task. :scratchch

GaryGB
 
#3
I would advise against trying to reverse-engineer MSE (or any purchased third-party add-in scenery) and its bgl files. You would likely be breaking any EULA and certainly infringing copyright of the developer and the owner of the copyright of the original imagery.

Follow the advice above. SBuilderX is one of the numerous free utility applications available from various links here on FSDeveloper that allow yo to grab imagery and set up the related bgl photo-scenery files. scenproc is then ideal for helping you to place mass scenery or use Annotator to add objects manually...
 

rhumbaflappy

Moderator
Staff member
Resource contributor
#4
As noted above, if you plan on distributing the completed scenery, it would violate the Mega Scenery Earth rights, and you could be fined or sued.

You can generally calibrate a scenery by determining the NSEW extents of a rectangular and aligned image. Some GIS programs allow an alignment to known positions, such as a landmark. I think gdalwarp might even allow this.
 
#5
Hi Ken:

Please explain what you mean by: "ground terrain for the Alabama Mega Scenery Earth around the (KBHM) airport".
I may not be using the correct words here but it's the ground scenery from Alabama Mega Scenery Earth I tried to work on a while back. In 1970, runway 36/18 was only 4,856'. Now, its 7,100', and when one uses that scenery for an airport that has been modified to what it was in 1970, that extra length will show in the sim. So, that extra length has to be taken out so that it won't show in the sim.


Also, please explain what you mean by: "I could not find a bitmap and all the images are bgl files".
Well, I don't know if I said it correctly. All I know is that all the images are bgl files and you can only view them in the SDK tmfviewer, and I don't know of any way to take that image and make a photo image out of it to use in SbuilderX. I wanted to use the original image so that it will blend or be the same match as the other tiles.


IIRC, we already identified the same or equivalent free online (color) imagery sources used in Alabama Mega Scenery Earth.
Yes, I thought we did but I could not find that exact image. I looked on google earth pro but I don't see it there. It should have been the one from 2017. It looks like google done something to the image or took it down. But, if I did use that image from google earth, I still would not have the coordinates that I would need to use in SbuilderX, so I need to use another site that imbeds those coordinates and provides a txt file. I know Earth Explorer uses a metadata that shows the coordinates but I tried to use them in the past and they did not work correctly.


Those imagery sources can be downloaded either directly by SBuilderX, or they can be downloaded from a online web portal such as Earth Explorer or USGS National Map via a web browser, re-projected in a GIS application, and then loaded into SBuilderX via the Add Map > From Disk method. :pushpin:
That's what I wanted to do but I did not see that image from 2017 in SbuilderX. I'll look again to make sure I didn't over look it. I found one at Earth Explorer but they had the airport image chopped up into 4 pieces, right on the edges, so to speak. I don't know if I'm going to the right place when I click on "Results" button trying to choose which sources, but 99% of the time, it shows nothing, or says no results, when I know it's out there. It shows all those sources when I can get the images and no one has explained to me which selection to make. I may not be using the correct ones and I have no idea what they mean. I hear that WGS84 is the one to choose but I don't see that choice anywhere. Whatever the case, I need an image that has the data coordinates information imbedded into the image. That was why I preferred to use SbuilderX. I didn't think about it at the time but when I launched SbuildX, went to File, Add Map, From Disk, a popup window tells me that I need to calibrate the image, and since I don't know the coordinates, this will not work.


Please explain what type of scenery you are trying to create at this time, and which FS utility you are using for each task. :scratchch
The Scenery I'm trying to create is a photo real ground scenery, as close as possible to what it was in 1970, for the time being, it will be for FSX. That's why I wanted to use that aerial image of KBHM from 1970 to make my photo real ground image, but have to wait until I get it to match, at least as close as possible, to the real satellite images. It's true that it's in B&W but it's no big deal for now.

Ken.
 
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#6
Hi Ken:

Please post a link to the imagery (which, IIUC, looked closest to Alabama MSE 2017 version ?) at EarthExplorer with the KBHM airport image 'chopped up into 4 pieces', either in a reply here in this thread, or via PM. ;)

With some ongoing effort on your part searching at USGS' EarthExplorer and The National Map portals, I believe you will likely be able to find public domain higher resolution imagery to freely download and use with better quality results in FS ...than that contained in MSE Alabama at only 1 Meter per pixel. :)

https://www.megasceneryearth.com/alabama-v3-2017.html


Please be assured that I shall continue to try and find the best method to accurately rotate and Geo-rectify the 1970 B+W aerial photo for use in SBuilderX as my limited available time allows, but I have no estimate as to when that may be achieved.

I would prefer to continue my study of the potential methods of achieving an accurate rotation and Geo-rectification without resorting to a very complex 'second order (N=2) Polynomial' method requiring use of numerous Ground Control Points (aka "GCPs").

GaryGB
 
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#7
I would advise against trying to reverse-engineer MSE (or any purchased third-party add-in scenery) and its bgl files. You would likely be breaking any EULA and certainly infringing copyright of the developer and the owner of the copyright of the original imagery.

Follow the advice above. SBuilderX is one of the numerous free utility applications available from various links here on FSDeveloper that allow yo to grab imagery and set up the related bgl photo-scenery files. scenproc is then ideal for helping you to place mass scenery or use Annotator to add objects manually...
No, I am not violating the EULA here as long as I don't use their image and sale it without their permission. What is Scenproc? I've never heard of it. You're correct that SbuilderX would be the utility to use to grab my image but so far, I haven't found the exact image that would match that 2017 bgl files in MSE, and I would need that to make it match.

Ken.
 
#8
As noted above, if you plan on distributing the completed scenery, it would violate the Mega Scenery Earth rights, and you could be fined or sued.
Hi rhumbaflappy,

No, I do not plan to distribute it, and I would never do that without there permission, but thanks for the warning. It's just for my personal use.


You can generally calibrate a scenery by determining the NSEW extents of a rectangular and aligned image. Some GIS programs allow an alignment to known positions, such as a landmark. I think gdalwarp might even allow this.
Yes, I did that but it came out way too large. I did not think about it at the time but guess what I did that I messed up on that would explain it? I cropped out some of the image that I did not need, and that messed up everything. So, one tip to remember is that if I use the NSEW extents, do not crop or take out some of the image.

Oh, another thing I need to mention is that I did not get that image from a bitmap, I guess you would call it. I had to get that image from inside FS and take a screenshot of it. So, doing it this way, there would have been no way of attaining the NSEW extents. I used the SDK tmfviewer to get the NSEW coordinates extents, and maybe I should of taking the screenshot using the tmfviewer and be sure not to crop out anything.

Ken.
 
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#9
Hi Ken:

Please post a link to the imagery (which, IIUC, looked closest to Alabama MSE 2017 version ?) at EarthExplorer with the KBHM airport image 'chopped up into 4 pieces', either in a reply here in this thread, or via PM. ;)

With some ongoing effort on your part searching at USGS' EarthExplorer and The National Map portals, I believe you will likely be able to find public domain higher resolution imagery to freely download and use with better quality results in FS ...than that contained in MSE Alabama. :)


Please be assured that I shall continue to try and find the best method to accurately rotate and Geo-rectify the 1970 B+W aerial photo for use in SBuilderX as my limited available time allows, but I have no estimate as to when that may be achieved.

I would prefer to continue my study of the potential methods of achieving an accurate rotation and Geo-rectification without resorting to a very complex 'Polynomial' method requiring use of numerous Ground Control Points (aka "GCPs").

GaryGB

Hi Gary,

I was going to post the link for you but it just shows the same link as the homepage. So, what I'll do is just tell you how I get there. On the home page, zoom into the KBHM airport and click on the airport. That will place the coordinates in that Search Criteria box at the left, and where it say Date Range, put in 1/1/2017 through 12/31/2017. Click the Data Sets button, and this is the page I'll be referring to when I mentioned about making the correct choices here. But I Choose Aerial Image and then check NAIP. I've noticed that when I hold the mouse curser over that, it says National Agriculture Image Program, but this may not be the one I need. But this one was the only choice that would turn up any images. Click the Results button and you'll see the 4 images. As I said, I may not be using the correct choices here, and what I've done is checked each one until I get an image. The thing I've noticed is that if I checked them all, I don't get any image at all. But if I checked them one at a time, the NAIP, for example, turns up images. But if you check another item and the NAIP, it won't show anything, so be aware of that. I don't understand why it does that, even when you check the one that has an image.

Ken.
 
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