What is the coordinate system of the exported xyz grid height map?

Question

Cartography

Exported height map in xyz Grid format from ASTER GDEM using GlobalMapper. I can't figure out what coordinate system is being used. Too large values ​​for degrees, minutes, seconds. Help me to understand. Here's a snippet:
6209425.034 4687356.956 529.819
6209425.034 4687318.738 529.966
6209425.034 4687280.519 528.415
6209425.034 4687242.301 525.632 6209425.034
4687204.082 524.464 6209425.034
4687165.864 525.634 6209425.034
4687127.645 528.074
6209425.034 4687089.427 531.51
6209425.034 4687051.208 537.781
6209425.034 4687012.990 545.043

Answer 1

GlobalMapper exports data (except when the format itself strictly limits it, like KML, for example) in the coordinate system that is selected for the workspace (main window) at the time of export. What system it is is indicated in the status line (at the bottom of the window, on the right) and in the configuration, Tools-Configure menu, Projection tab.
Also, you were probably prompted to save the projection file during export.
Guessing by your numbers is meaningless (although I can assume that this is a UTM projection), it's easier for you to look in the program yourself.

Answer 2

Include the RedBeanPHP\OODBBean class before unserizlize.
Also see a similar question on SO