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Height Maps

Posted: Fri Nov 23, 2018 2:57 pm
by 22sec
If anyone wants me to provide height Maps for Maps I will be happy to do so. Just post in this thread the coordinates you want, and I will post the file once I’ve had a chance to export.

RE: Height Maps

Posted: Fri Nov 23, 2018 3:37 pm
by CCIP-subsim
Cheers, thank you! [:)]

The approximate 4 corners of the elevation map I need for Chechnya:

1) 43.647055 N 45.509926 E
2) 43.416193 N 46.200823 E
3) 42.911258 N 45.880493 E
4) 43.145613 N 45.187463 E

(No problem if it's a little off! The map is a bit tilted on purpose and, after some hands-on time with AB map editing, I'm realizing that there's a lot of manual tweaking needed in any case to make things line up and not look strange).

Thanks very much in advance! [:)]

RE: Height Maps

Posted: Fri Nov 23, 2018 4:15 pm
by 22sec
I have to export the data within square or rectangular boundaries with a north, east, south, and west coordinate for each side. So I took the coordinates that were the furthest of the four cardinal directions. If this won't work for you we can try something else.

https://drive.google.com/open?id=1R2I0a_Ktp6xoIDbBv4aWd_Aiu2ZURr2p

RE: Height Maps

Posted: Fri Nov 23, 2018 4:39 pm
by CCIP-subsim
No worries, that's how I did the terrain maps too! That actually makes it easier for me to line it up with the terrain map. I still have to do a little tweaking and aligning, and there's a few impassable areas I'll need to "massage" a little bit - but it's perfect for what I needed in terms of getting started.

Thanks very much!

Image

RE: Height Maps

Posted: Sat Nov 24, 2018 6:13 am
by Af1352pasha
Hi

Please kindly make a height map for below area:

Left Longitude input= 47.7562
Right Longitude input= 48.4923
Top Latitude input= 31.8834
Bottom Latitude input= 31.2868

RE: Height Maps

Posted: Sat Nov 24, 2018 10:53 am
by 22sec
ORIGINAL: Af1352pasha

Hi

Please kindly make a height map for below area:

Left Longitude input= 47.7562
Right Longitude input= 48.4923
Top Latitude input= 31.8834
Bottom Latitude input= 31.2868


Here you go.
https://drive.google.com/open?id=1c8O9cTAZN3JX0syNcN2XGUEEo2HudPXa

RE: Height Maps

Posted: Sat Nov 24, 2018 1:27 pm
by Af1352pasha
[&o][&o][&o]

RE: Height Maps

Posted: Tue Nov 27, 2018 10:33 pm
by exsonic01
Hello 22sec, could you please generate a height.bmp file for following coordinate?

Latitude - Longitude
TOP RIGHT 38.991145 N, 125.956972 E
TOP LEFT 38.970507 N, 125.248878 E
BOT RIGHT 38.438237 N, 125.980347 E
BOT LEFT 38.418000 N, 125.277664 E

This is exactly 61440m x 61440m. Just in case, following is the link of google drive link for zip file.
https://drive.google.com/file/d/1SogmwP ... sp=sharing
This zip file contains tif / tiff / bmp image of SRTM data for the area I presented above, which is shown in this post: fb.asp?m=4560811 Southern approach route to city of Pyongyang.
Those tif / tiff / bmp images are exactly synced with the zone I cropped, but those might not contains the height data. It is possible they lost height information while exporting to images. If that is the case, ignore those files, and please generate the height.bmp from the coordinate written above.

Thank you

RE: Height Maps

Posted: Tue Nov 27, 2018 11:26 pm
by 22sec
I had to take the furthermost points again of the coordinates you gave me. In the future, give me the western and eastern longitude line, and northern and southern latitude lines. That is how I have to export the data in GM.

https://drive.google.com/open?id=1NFLGpR8e_kGG3i1ehMEIx8Y6H2_B0r_i

RE: Height Maps

Posted: Tue Nov 27, 2018 11:39 pm
by exsonic01
ORIGINAL: 22sec
I had to take the furthermost points again of the coordinates you gave me. In the future, give me the western and eastern longitude line, and northern and southern latitude lines. That is how I have to export the data in GM.

https://drive.google.com/open?id=1NFLGpR8e_kGG3i1ehMEIx8Y6H2_B0r_i
Ooops, sorry, I don't have global mapper so I didn't know about that.

West Latitude = 38.970507 N
East Latitude = 38.438237 N
North Longitude = 125.248878 E
South Longitude = 125.980347 E

Is this looks better? Those are coordinate of top left corner and bottom right corner. I will keep in mind this.

Thank you so much!


RE: Height Maps

Posted: Tue Nov 27, 2018 11:54 pm
by exsonic01
22sec, it seems that the height data you send me is slightly off from the terrain maps I have. Could you let me know what CRS was used and which coordinate you chose? I used WGS 84 - UTM zone 52N. I may need to reprint the map based on your setting.

RE: Height Maps

Posted: Tue Nov 27, 2018 11:59 pm
by 22sec
ORIGINAL: exsonic01
ORIGINAL: 22sec
I had to take the furthermost points again of the coordinates you gave me. In the future, give me the western and eastern longitude line, and northern and southern latitude lines. That is how I have to export the data in GM.

https://drive.google.com/open?id=1NFLGpR8e_kGG3i1ehMEIx8Y6H2_B0r_i
Ooops, sorry, I don't have global mapper so I didn't know about that.

West Latitude = 38.970507 N
East Latitude = 38.438237 N
North Longitude = 125.248878 E
South Longitude = 125.980347 E

Is this looks better? Those are coordinate of top left corner and bottom right corner. I will keep in mind this.

Thank you so much!



OK, give me a sec and let me do these.

RE: Height Maps

Posted: Wed Nov 28, 2018 12:03 am
by 22sec
ORIGINAL: exsonic01

22sec, it seems that the height data you send me is slightly off from the terrain maps I have. Could you let me know what CRS was used and which coordinate you chose? I used WGS 84 - UTM zone 52N. I may need to reprint the map based on your setting.
125.248878

UTM Zone 51N

RE: Height Maps

Posted: Wed Nov 28, 2018 12:06 am
by 22sec

RE: Height Maps

Posted: Wed Nov 28, 2018 12:27 am
by exsonic01
Thank you, but this is still off... Let me check my setting again. Or I may need to find the way to match this using GIMP or Photoshop.

Are those height files based on UTM Zone 51N?

RE: Height Maps

Posted: Wed Nov 28, 2018 12:46 am
by exsonic01
Just in case, could you try with CRS UTM Zone 52N and just WGS 84 (pseudo - Mercator) if possible? Sorry for inconvenience. We have longitude and latitude, so it will be able to match once we find good match. I'm trying WGS84-UTM zone 51N now.

RE: Height Maps

Posted: Wed Nov 28, 2018 1:57 am
by exsonic01
22sec, sorry for inconvenience, but it seems that all of my maps are done via WGS84 - pseudo Mercator CRS. It is my mistake. I thought I set as UTM zone 52N, but for some reason sync was broken and all maps were done via pseudo Mercator. (Psuedo-Mercator is default option. Maybe I forget the check the sync during save & load of the project)

I will try to get the map via UTM zone 51N and 52N, which is your height map file used. (I think the second file used 52N, right?) Could you try to repeat the height map process with pseudo Mercator? Sorry.

RE: Height Maps

Posted: Wed Nov 28, 2018 10:13 am
by 22sec
I can, but it will be this evening before I get to it.

RE: Height Maps

Posted: Thu Nov 29, 2018 1:19 am
by exsonic01
I checked my project again. From QGIS, I set project CRS to WGS84 - UTM 52N. Then I load map layers, CRS for map layers is automatically adjusted to WGS84 - Pseudo Mercator, while project CRS is still WGS84 - UTM 52N. This is because layer CRS should sort themselves for on-the-fly transformation based on WGS84. Each layers have slightly different base CRS for WGS84 system. SRTM use WGS84/Geo, OSM use WGS84/pseudo, and etc...

I think this is the reason why my maps have WGS84 - Pseudo Mercator CRS. If you send me WGS84 - Pseudo Mercator CRS version of height.bmp, I will check it out.

Meanwhile, what I'm doing is prepare the satellite map with same scale but slightly larger area in size. This way, I can move or rotate my satellite map to match with your height.bmp.

If you are interested, I can send you my QGIS project file for QGIS 3.4.1. It is free tool, so you should be able to check what I did. Let me know if you want.

RE: Height Maps

Posted: Thu Nov 29, 2018 11:32 am
by exsonic01
Now I see why my map is not projected on yours... Because my map is based on Pseudo Mercator, it is not orthogonal to latitude and longitude lines. That is why the coordinate of 4 corners have different latitude and longitude lines for each, from above post (fb.asp?m=4560820).

Now I'm trying to get the map orthogonal to lat and long coordinate. But in this case, I'm not sure if my map will be exactly 61.440km because latitude and longitude is not perfect line...

Can anyone help me with this one? Is the 61.440km means the direct distance? Or arc distance?