^pof;
Remote;
Sensing;
and;
GIS,;
Peking;
University,;
Beijing;
100871,;
China;
^pKey;
Laboratory;
for;
Information;
Engineering;
in;
Surveying,;
Mapping;
and;
Remote;
Sensing,;
Wuhan;
University,;
Wuhan;
430079,;
China;
^pInstitute;
ofSurveying;
and;
Mapping,;
Beijing;
100038,;
China;