Google Earth

[Anders]

Another good source for absolutely free maps is Google Earth.
Many places on earth has very good resolution.
Some tips:
An altitude of 1000 to 2000m gives good resolution.
Save every image with and without Lat/Long grid (Ctrl-L to toggle)
Use the image with grid for calibration, use the calibration file with the image without grid.
Be sure "Terrain" is unchecked!
When using Google Earth Plus or Pro images can be saved in higher resolution.
I use TTQV for calibration.

[olac]

Great tip !
I will try your method, thanks !

[olac]

Another good source for absolutely free maps is Google Earth.
...
Use the image with grid for calibration, use the calibration file with the image without grid.
...
I use TTQV for calibration.

Hi Anders,
Could you explain more precisely how you can import the calibration of the "grid-image" into the "non-grid image" in TTQV.
I don't know how to re-use old calibration with new image.
Thanks.

[Anders]

Hi Anders,
Could you explain more precisely how you can import the calibration of the "grid-image" into the "non-grid image" in TTQV.
I don't know how to re-use old calibration with new image.
Thanks.

Let's say you have saved the two maps with the names "map.jpg" and "map-grid.jpg". When you calibrate "map-grid.jpg" with TTQV you will get a calibration file called "map-grid_jpg.cal". Simply rename that file to "map_jpg.cal" and it will be a valid calibration file for "map.jpg" because the two map files have exactly the same coverage. In TTQV X-plorer the map name will still show "map-grid.jpg" because X-plorer get the name from the calibration file.

[olac]

Thanks Anders
it's a great tip !

[hainguyen178]

it's useful, thank you!