FSXA Questions About QGIS

[kmanning]

My primary concern was that you had the airfield itself contained within the aerial imagery, since that could be used to reconstruct the objects as they were at the time you wish to represent in a historical version of KBHM.

It would still be an impractical task to do a polynomial rotated reprojection of the historical B+W extended aerial imagery surrounding KBHM

Yes, I agree.

but the airfield itself may be fitted manually using SBuilderX and Sketchup, so that you can make an AB Flatten, adjust RWY axes / lengths, and reconstruct objects fairly accurately ...for the historical year of interest.

I'm just wondering which would benefit me most. Just continue from where we left off using the stock airport file or create a new satellite image using SbuilderX. I assume that if I later decided to use the older 1970 image, the procedure would still be the same, except the fact that I would have to reconstruct the airport background of course. The main thing is that I learn how to process the things you're going to cover using the tools in SbuilderX and Sketchup. If the process is the same with any image I use, I'll just create a new KBHM image in SbuilderX and post them here later or tomorrow.

Ken.

 

[GaryGB]

If you attach a SBuilderX saved *.SBP Project file and SBuilderX exported *.SBX Exchange file, I can use the tile download and default land class instructions in those files to retrieve the map tiles and display custom plots of default CVX Vectors for the intended project directly onto my own computer, without your having to upload and link large file sets.

GaryGB

 

[kmanning]

Hi Gary,

Here are the 2 SbuilderX files:

 

[GaryGB]

AFAIK, you now have a version of your project with the ESRI FLX2420 Shapefile 'Append' to SBuilderX performed as I described:

"SBuilderX Menu > View > Show Background - F1

SBuilderX displays selected tileserver imagery behind the KBHM AB Flatten Polygon, in preparation for modifications."


The current file set you attached immediately above did not show that Appended CVX Vector object, so I have added it on my computer.


The current aerial imagery available from Google and/or MS Virtual Earth (BING) is higher resolution and sharper.

This allows zooming to see small details, as at some point you plan to make a version of KBHM with a modified historical configuration.


But you do also need to have aerial imagery for KBHM from the specified time period calibrated and displayed in SBuilderX as a "Map".

That chosen historic aerial imagery you cited above, must be Appended as a BMP file type with a EPSG:3857 GIS Projection.

This can be done in yet another copy of your project; I suggest using easy-to-follow names for the copied projects.


NOTE: We must keep in mind that KBHM RWY axes / lengths have changed over the years as you had most recently explained here:

https://www.fsdeveloper.com/forum/threads/why-is-this-runway-designated-as-closed.456047/


CAVEAT: It is likely that all existing copies of historical aerial imagery you cited above is not calibrated precisely, and needs re-calibration.

https://www.fsdeveloper.com/forum/threads/questions-about-qgis.460216/post-935655


I have a copy of the the aerial imagery you cited above in (relative and comparable) high resolution, that I shall attempt to re-calibrate.

I must perform this via an alternate method of Polynomial re-projection 'visually' within SBuilderX' workspace using landmark references.


I can 'Move' a selected Map of historical aerial imagery closer to align with current aerial imagery from a SBuilderX tiledownloader Map.

However, I shall first need to draw more landmark vector outlines of objects from the historic aerial imagery within SBuilderX' workspace.


I believe I may then be able to achieve a maximally precise alignment of the re-calibrated historical- and current- aerial imagery.

I will keep you posted as to when I have achieved a maximally precise alignment of re-calibrated historical- and current- aerial imagery.


In the mean time, you may wish to work with the Appended FLX2420.SHP Polygon to fit it into the MSVE aerial imagery AB Flatten areas.

Then you will be able to compare historical and current versions of KBHM airfield in FSX, in preparation for editing Approach data in ADE.

GaryGB

 

[kmanning]

AFAIK, you now have a version of your project with the ESRI FLX2420 Shapefile 'Append' to SBuilderX performed as I described:

"SBuilderX Menu > View > Show Background - F1

SBuilderX displays selected tileserver imagery behind the KBHM AB Flatten Polygon, in preparation for modifications."


The current file set you attached immediately above did not show that Appended CVX Vector object, so I have added it on my computer.

Hi Gary,

I didn't know you wanted me to also append that FLX2420. I thought you just wanted me to pick an image to begin with the tutorial. Anyway, I've attached the SBP and SBX files, including the FSX2420 below, in case you need them. I hope I got it right. By the way, did you wanted me to go ahead and adjust the FLX2420 boundaries to match the image or wait till we begin the tutorial?

This allows zooming to see small details, as at some point you plan to make a version of KBHM with a modified historical configuration.

Yes, I'm planing to do that.

But you do also need to have aerial imagery for KBHM from the specified time period calibrated and displayed in SBuilderX as a "Map".

Well, I can do this. There is a website called 'Historic Aerials.' Here's the website:

NETRonline: Historic Aerials

Historic Aerial Photos and Maps

www.historicaerials.com

Check it out and see what you think. I can purchase a high resolution from those years, say around 1970s or the 1980s. As far as I know, they're already re-projected to the WSG84 and I can download them as a Geo tiff. This way we won't have to go through the trouble of calibrating and re-projecting. There is a metadata that comes with the image I've posted above but I can't find in anywhere on my computer. I would post it if I can find it.

NOTE: We must keep in mind that KBHM RWY axes / lengths have changed over the years as you had most recently explained here:

Yes, not to mention that the hill on the north side has changed tremendously.

CAVEAT: It is likely that all existing copies of historical aerial imagery you cited above is not calibrated precisely, and needs re-calibration.

You're correct. When I first created this airport in ADE using this image, I had to line up both runways and adjust the length of the runways in the image to match the runways in ADE. The longer runway was 10,000' for runway 5/23 and runway 36/18 was 4,856' Runways 5/23 is now 6/24 due the changes in the earth's magnetic filed.

I have a copy of the the aerial imagery you cited above in (relative and comparable) high resolution, that I shall attempt to re-calibrate.

Okay. If it's too much work and cannot be re-calibrated, we can wait later and I'll purchase them from a website called Historical Aerials.

I believe I may then be able to achieve a maximally precise alignment of the re-calibrated historical- and current- aerial imagery.

I will keep you posted as to when I have achieved a maximally precise alignment of re-calibrated historical- and current- aerial imagery.

Okay.

In the mean time, you may wish to work with the Appended FLX2420.SHP Polygon to fit it into the MSVE aerial imagery AB Flatten areas.

Please let me know what you mean by MSVE but I assume you're saying to fit and adjust the polygon around the air boundary.


Ken.

 

[kmanning]

Hi Gary,

Here's a pdf file of a Report Of Calibration but this has more to do with the camera than with re-projection so this probably won't help you.

 

[kmanning]

Hi Gary,

I think I've found it. Here's the metadata I've downloaded from Earth Explorer. It provides all the coordinates that may help you calibrate this image. Just make sure you select AR1VCJW00010056 in the Entity ID at the left. I hope that will give you the information you need to calibrate it.

Ken.

 

[GaryGB]

Hi Gary,

I didn't know you wanted me to also append that FLX2420. I thought you just wanted me to pick an image to begin with the tutorial. Anyway, I've attached the SBP and SBX files, including the FSX2420 below, in case you need them. I hope I got it right.

By the way, did you wanted me to go ahead and adjust the FLX2420 boundaries to match the image or wait till we begin the tutorial?

Any current aerial imagery tiles downloaded via SBuilderX' built-in tile downloader are likely already calibrated to a reasonable extent of precision.

Well, I can do this. There is a website called 'Historic Aerials.' Here's the website:

NETRonline: Historic Aerials

Historic Aerial Photos and Maps

www.historicaerials.com

Check it out and see what you think. I can purchase a high resolution from those years, say around 1970s or the 1980s.

As far as I know, they're already re-projected to the WGS84 and I can download them as a Geo tiff. This way we won't have to go through the trouble of calibrating and re-projecting. There is a metadata that comes with the image I've posted above but I can't find in anywhere on my computer. I would post it if I can find it.

I am fairly certain I may have seem the 'Historic Aerials' info previously.

Comparing matched imagery displayed in their preview window with AR1VCJW00010056 (free) in SBuilderX, shows SBuilderX' display is sharper.

But to be fair, I would have to compare their GeoTiff rather than a raster image purposely derived for use in a web page composition application.


Regarding "WGS84 projection" (aka EPSG:4326), that is the warped format used when submitted to SDK compilers, Google Earth, Sketchup etc.

That is because those applications automatically re-project internally from WGS84 (EPSG4326) to a non-warped "Map" view in EPSG:3857 projection.


When a BMP is Added as a Map from Disk to SBuilderX and is 'intended' to be displayed in a "Map" view, it is not 'automatically' re-projected.

So, when a BMP is Added as a Map from Disk to SBuilderX and is 'intended' for display in a "Map" view, it 'may' need to be manually re-projected.


A non-warped "Map" view in SBuilderX requires EPSG:3857 projected aerial imagery in 24-Bit BMP graphic file format.

So if a warped WGS84 (EPSG4326) BMP is to be Added as a Map From Disk to SBuilderX in a project, it must first be re-projected to EPSG:3857


When Map viewers like Google Earth / Maps, MSVE (Microsoft Virtual Earth (aka BING) etc. 'serve' imagery tiles, they are already EPSG:3857 projected

When SBuilderX downloads aerial imagery tiles, it also is able to display them in a non-warped "Map" view ...as they are already EPSG:3857 projected.


In SBuilderX that non-warped "Map" view is referred to as the "Background" of the work-space.

If we Add Map > From Background, SBuilderX automatically re-projects EPSG:3857 tiles internally to EPSG4326 projection when compiled to BGL.


Unless the $ GeoTIFF imagery is much higher resolution and sharper visually, you may not need imagery other than AR1VCJW00010056 (free).

Yes, not to mention that the hill on the north side has changed tremendously.

Are you saying you need to "Terraform" the hill 'shape'... in addition to just restoring a residential area with streets and houses ?

You're correct. When I first created this airport in ADE using this image, I had to line up both runways and adjust the length of the runways in the image to match the runways in ADE. The longer runway was 10,000' for runway 5/23 and runway 36/18 was 4,856' Runways 5/23 is now 6/24 due the changes in the earth's magnetic field.

If it's too much work and cannot be re-calibrated, we can wait later and I'll purchase them from a website called Historical Aerials.

I have free AR1VCJW00010056 (Hi-Res, B+W) EPSG:3857 aerial imagery calibrated in "close" proximity to MSVE imagery / Appended FLX2420.SHP.

It just needs some fine-tuning with the assistance of traced / outlined objects from current imagery for final precise calibration.


This was impractical to do in Global Mapper as its virtual calibrations were not IRL Geographic coordinates; but if moved / rotated, it required IRL.

That proved appallingly cumbersome, and imprecise as to resulting increments of Geographic coordinates changed, if moved / rotated


Options in SBuilderX and Sketchup both allow precision- and ease of use- for manually moving / rotating objects mapped with aerial imagery.

Please let me know what you mean by MSVE but I assume you're saying to fit and adjust the polygon around the KBHM airfield boundary (aligned to MSVE imagery).

MSVE = Microsoft Virtual Earth = BING

GaryGB

 

[kmanning]

So if a warped WGS84 (EPSG4326) BMP is to be Added as a Map From Disk to SBuilderX in a project, it must first be re-projected to EPSG:3857

I can do that using QGIS.

Are you saying you need to "Terraform" the hill 'shape'... in addition to just restoring a residential area with streets and houses ?

No, not exactly. The hill slope is still basically the same. At the top of the hill, the national guard owns that property now and it used to be a residential area with houses. We moved into my grandparents home in 1974 and we moved in 1977. The residential actually was down in a small valley like hollar that sloped downhill from the top. All of that is level now but on top of the hill.

In the mean time, you may wish to work with the Appended FLX2420.SHP Polygon to fit it into the MSVE aerial imagery AB Flatten areas.

Okay. Did you want me to post it when I've completed it or just let you know when I've competed it?


Ken.

 

[kmanning]

Hi Gary,

Just wanted to let you know that I have my airport boundary completed using the SbuilderX background image. I used the polygon tool rather than editing the FLX2420. I hope that's okay. The FLX2420 seems to be chopped up with lines in the middle of the polygon.


Ken.

 

[GaryGB]

Initial inspection of the latter SBuilderX Project appears to show good precision with the Polygon Vector object.

We will add the *.SBP project file name only (not file extension) to the SBuilderX File Properties field.

We will also need to assign a CVX Vector Land Class AB Flatten GUID (3-component) to Properties of the Polygon.

Once both tasks are completed, save the Project to a *.SBP file, and also export a SBuilderX *.SBX exchange file; then attach the updated files here.

GaryGB

 

[kmanning]

We will add the *.SBP project file name only (not file extension) to the SBuilderX File Properties field.

When I first started my project, I did create a project name for my project but when I opened my project in Properties, I noticed it didn't show a project name. I think it's because when I saved my project as Save As, I used another name so that I wouldn't write over it.

We will also need to assign a CVX Vector Land Class AB Flatten GUID (3-component) to Properties of the Polygon.

I thought of that when I went to bed last night and I never assigned it a vector type. I assigned it AB_Flatten_MaskClassMap_Exclude Atogen. The zip is attached below:


Ken.

 

[kmanning]

Hi Gary,

I was going over the tutorial you've posted above recently called Terrain Design For Flight Simulator X by Luis Féliz-Tirado. It's about St. Barths airport, a small island about 20 miles from St. Marteen. The one thing I just found out is that unlike ADE, all hydro polygons and airport flattens must have their altitudes assigned in the properties. You'll noticed that the airport background flatten that I've posted today will say 0. The next time I post it, it'll have the altitude assigned. I assume I put in the same altitude that is used by ADE in meters. I will assign the altitude 196.291 meters.

Ken.

 

[GaryGB]

Are you saying you need to "Terraform" the hill 'shape'... in addition to just restoring a residential area with streets and houses ?

No, not exactly. The hill slope is still basically the same. At the top of the hill, the national guard owns that property now and it used to be a residential area with houses. We moved into my grandparents home in 1974 and we moved in 1977. The residential actually was down in a small valley like hollar that sloped downhill from the top. All of that is level now but on top of the hill.

Please make a MS-Paint screenshot of either / both linked 1959 Geo-PDFs zoomed in to areas marked where terrain 'appears' changed after ~1970:

https://prd-tnm.s3.amazonaws.com/St...AL_Birmingham North_303240_1959_24000_geo.pdf

https://prd-tnm.s3.amazonaws.com/St...L/24000/AL_Irondale_304262_1959_24000_geo.pdf


Source: https://ngmdb.usgs.gov/topoview/viewer/#13/33.5643/-86.7553


I would like to perform an analysis of the Topo contours on the area in question, to compare with those contours derived from the local LIDAR.

GaryGB

 

[kmanning]

Please make a MS-Paint screenshot of either / both linked 1959 Geo-PDFs zoomed in to areas marked where terrain 'appears' changed after ~1970:

Hi Gary,

MS Paint does not support opening a pdf file. Let me convert it to a bmp using Gimp then MS Paint should be able to open it. I guess MS Paint is the program you prefer to use. I guess I'll do both links because each one has a portion of the airport cut off. The area where the hill has changed over the years is exactly north and north-east of runway 36/18. The area is called Meadwood Heights. The elevation has not changed that much but some of the streets no longer exist and is covered up by dirt.

Ken.

 

[GaryGB]

I actually meant, copy the image using Adobe Acrobat Reader DC (which is still available) and paste it into Windows / MS Paint, then circle the AOI(s).

I just use Paint as it has a quick and easy startup, rather than another graphics app (I go for a coffee break when starting some graphics apps).

If you use GIMP, you could probably take a short nap to catch up on some sleep while it loads, then use it instead of Paint.

https://get.adobe.com/reader/


PS: I may load these Geo PDF's into Global Mapper (they are sharper than the GeoTIFFs) to see what can be derived via Raster-to-Vector conversion.

Then we have an easier work-flow to derive ESRI Shapefiles, that can be imported into SBuilderX and Sketchup.


The converted Topo Contour lines may prove useful if a custom TIN is needed locally to modify the LIDAR 1M DTM when making your historic version.

GaryGB

 

[kmanning]

Well, I guess I finally got it. Normally in Acrobat Reader, I can highlight the area I wanted to copy and copy it with no problem. But every time I clicked to copy the area of interest, it would resized and move to a different position and I've never had that problem. So, I just zoomed in and took a screenshot and pasted it into MS Pain. That's why it took me so long. Anyway, here are the images:

The area I have circled in red is the area we lived at. I think it was 58th street. This area had a depression. When you turned off East Lake Blvd, you go up the hill and then would level off. When you turn onto the street, it would to downhill to a residential area. This is all covered with dirt and concrete now and is owned by the national guard. As far as the elevation, I think there would be small differences, if any. The only thing really different is the landmark and streets being re-routed. But as I said, we can just use the current image in SbuilderX if you want to.

Ken.

 

[GaryGB]

At such time as you may wish to further pursue making a historic version of the AOI, you can use a GIS application to export BMPs with a BMP 'World' file customized to the format SBuilderX reads as a Geo-referencing TXT file, and then Add Map From Disk into SBuilderX workspace as a Map.

You should recall the workflow you used previously at KATL:

https://www.fsdeveloper.com/forum/t...cts-in-sbuilderx-for-katl.444877/#post-818288


You could also Open the Geo PDFs in Google Earth Desktop Edition to trace over and generate KML files for processing via FSX_KML and Sketchup.

https://www.fsdeveloper.com/forum/forums/fsx-kml.81/


Raster-to-Vector conversion of Topo Contour Lines could be derived via Center Tracing at up to ~10 Meter Horizontal / 20 Meter Vertical Resolution,

The latter might prove useful in making a pre-1980's historic version of local terrain as a TIN that modifies the current 1-Meter LIDAR terrain mesh.


We can take a look at the those options after first making a version of the current KBHM airfield that fits and works properly in FSX.

FYI: Save all source / work files; you could ultimately process the data later to make custom KBHM versions for import into MSFS Scenery Editor.

GaryGB

 

[kmanning]

You could also Open the Geo PDFs in Google Earth Desktop Edition to trace over and generate KML files for processing via FSX_KML and Sketchup.

https://www.fsdeveloper.com/forum/forums/fsx-kml.81/

Can this be done in google earth pro? That's the version I have. Do I have to use the desktop edition? If so, is the desktop version still available? The Pro version seems to have worked just fine importing kml files.

We can take a look at the those options after first making a version of the current KBHM airfield that fits and works properly in FSX.

When do we start?

FYI: Save all source / work files; you could ultimately process the data later to make custom KBHM versions for import into MSFS Scenery Editor.

I am saving all these files.


Ken.

 

[GaryGB]

Can this be done in google earth pro? That's the version I have. Do I have to use the desktop edition? If so, is the desktop version still available? The Pro version seems to have worked just fine importing kml files.

AFAIK, Google Earth Desktop Edition and Google Earth Pro are one and the same.

I use: "Google Earth Pro on desktop" version 7.3.4.8642 (64-bit)

https://www.google.com/earth/about/versions/

https://dl.google.com/tag/s/appguid={65E60E95-0DE9-43FF-9F3F-4F7D2DFF04B5}&iid={65E60E95-0DE9-43FF-9F3F-4F7D2DFF04B5}&lang=en&browser=4&usagestats=0&appname=Google%20Earth%20Pro&needsadmin=True&brand=GGGE/earth/client/GoogleEarthProSetup.exe


To open 1959 USGS Topo maps for the KBHM AOI:

Google Earth Pro Menu > File > Open > File Type: Geospatial PDF (*.pdf) > Browse / Select ex:

* AL_Birmingham North_303240_1959_24000_geo.pdf

...and:

* AL_Irondale_304262_1959_24000_geo.pdf

NOTE: I am purposely not using the KMZ files linked via the USGS TopoViewer search results for 1959, as the Geo PDFs are sharper.



To work on the current version of KBHM:

In SBuilderX, select the updated 2D CVX KBHM Airport Boundary Flatten you made by aligning it with background aerial imagery.

Compile to BGL.

In [SBuilderX install path]\Tools\Shapes sub-folder copy all files just made during compilation by SDK SHP2VEC.

Paste those files into your working KBHM project folder.

Google Earth Pro Menu > File > Open > File Type: ESRI Shape (*.shp) > Browse / Select ex:

FLX2420.shp



CAVEAT: Since QGIS may also have the ability to Open Geospatial PDF files, and may also have the ability to perform comparable tasks:

We should now decide if it is best to proceed with discussion of the workflow I propose in this same QGIS-related thread.

[EDITED]

I have endeavored for some time to prompt your awareness of the importance of keeping threads brief, and focusing on a primary topic.

While there are a few exceptionally long posts here at FSDEV which merited longer extents, it is typically best to not exceed 1 or 2 pages.


I would encourage others to continue contributing further helpful input here on how to use QGIS for your designated tasks at KBHM.

I shall leave it up to you and admins to decide if it is best to start other threads on specific types of tasks at KBHM requiring use of QGIS.


My recommendation is to think your project through, decide what task is next indicated, and start a new thread in a task-specific forum.

[END_EDIT]

When do we start?

IIUC, your first goal is to modify a 2D CVX KBHM Airport Boundary Flatten you made by aligning it with background aerial imagery.

We can modify a 3D CVX if you attach ZIPed SBuilderX *.SBP / *.SBX files with your AB Flatten updated to FSX' default KBHM ARP Altitude:

Hi Gary,

I was going over the tutorial you've posted above recently called Terrain Design For Flight Simulator X by Luis Féliz-Tirado. It's about St. Barths airport, a small island about 20 miles from St. Marteen. The one thing I just found out is that unlike ADE, all hydro polygons and airport flattens must have their altitudes assigned in the properties. You'll noticed that the airport background flatten that I've posted today will say 0. The next time I post it, it'll have the altitude assigned. I assume I put in the same altitude that is used by ADE in meters. I will assign the altitude 196.291 meters.

Ken.

I am saving all these files.

Good.

GaryGB