Export to geotiff from google earth, some area is always blank

yjzhang123

When I download data from google earth, it is ok as following:

1.jpg

But when I export the area to geotiff, it is always blank as following:
2.jpg

you may try this to download test.kml. Thanks for any help.

global_mapper

Are you exporting from Google Earth or from in Global Mapper? I'm not quite sure the procedure to get the bottom image.

Thanks,

Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

yjzhang123

I got the bottom image in GM. Thanks.

global_mapper

The KML file just has an area and a line feature in it, there isn't any imagery in the KML file itself. Do you maybe need to load some imagery in Global Mapper for that area using the File->Download Online Imagery/Data menu command?

Thanks,

Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
http://www.bluemarblegeo.com/

yjzhang123

Yes, I use google earth as Imagery source.

global_mapper

Have you somehow added Google Earth as an imagery source in Global Mapper? I guess I'm still not sure exactly which direction you are going. As far as I know there is not any way to stream the Google Earth data sources into Global Mapper. You can go the other way, but the Google Earth data sources are not accessible outside of that application.

Thanks,

Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

yjzhang123

You can visit goolge earth to add following line to wms_user_sources.txt:

GMAP|png|-180.00000000000000000,-90.00000000000000000,180.00000000000000000,90.00000000000000000||19|256|900913|<>|google earth*http://khm1.google.com/kh/v=128&src=app&x=%x&y=%y&z=%z&s=Galileo

Thanks

global_mapper

That is interesting, I wasn't aware that you could access the Google Earth imagery externally through a simple URL like that. Of course it violates the Google Terms of Service to do so, so we could never add this as a built-in to Global Mapper, but it certainly does work!

It looks like the Google Earth imagery isn't populated all the way down at that location. I just did an export at 1 meter per pixel in your area and got the attached results. You may just want to change your export resolution.

Thanks,

Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

yjzhang123

I think, it is strange that I can view the image correctly as the top picture, but it does not work when I try to export the same area. Is there any different between viewing and exporting?

Thanks

global_mapper

The sample spacing/resolution that you export could be the issue. Try 1 meter resolution in each direction and see if that works.

Also are you checking to include vector features when exporting? You might try unchecking that. Also what version of Global Mapper are you using?

Thanks,

Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

yjzhang123

Anyway, after I decreased the resolution, it works. Thanks for your help.
In the next version, I suggest to add a new function which can log exporting process.

Thanks again