Laboratory;
of;
Digital;
Earth;
Sciences,;
Institute;
of;
Remote;
Sensing;
and;
Digital;
Earth,;
Chinese;
Academy;
of;
Sciences,;
Beijing;
100094,;
China;
of;
Chinese;
Academy;
of;
Sciences,;
Beijing;
100049,;
China;
Centre;
on;
Space;
Technologies;
for;
Natural;
and;
Cultural;
Heritage;
under;
the;
Auspices;
of;
UNESCO,;
Beijing;
100094,;
China;
Astronomical;
Observatories,;
Chinese;
Academy;
of;
Sciences,;
Beijing;
100012,;
China;