the vertical distance between two consecutive contours
the horizontal distance between two consecutive contours
the vertical distance between two points on same contour
the horizontal distance between two points on same contour
hypsometry
barometric levelling
spirit levelling
trigonometrical levelling
tacheomefry
plane table surveying
theodolite surveying
forests
urban areas
hilly areas
plains
radiation
traversing
resection
all of the above