The curvature of the Earth’s surface is taken into account only if the extent of survey is more than
a) 80 sq km
b) 500 sq km
c) 260 sq km
d) 1500 sq km
The curvature of the Earth’s surface is taken into account only if the extent of survey is more than
a) 80 sq km
b) 500 sq km
c) 260 sq km
d) 1500 sq km