GSQ Mt Isa Southeast elevation line data

Digital Elevation Model data record the terrain height variations from the processed point-located data recorded on an airborne geophysical survey.� The aircraft altimeter data records the height of the aircraft above the ground and the aircraft GPS records the height of the aircraft above the ellipsoid.� Subtracting the two values enables the height of the terrain beneath the aircraft relative to the ellipsoid to be calculated.� This ellipsoidal terrain height is corrected for the variation between the ellipsoid and the geoid (the n-value correction) to produce terrain heights relative to sea level.

数字高程模型（Digital Elevation Model）数据通过处理航空地球物理测量中记录的点位数据，来记录地形高度变化。飞机高度计数据记录飞机相对于地面的高度，而飞机全球定位系统（GPS）数据记录飞机相对于椭球体的高度。将这两个数值相减，即可计算出飞机下方地形相对于椭球体的高度。该椭球体地形高度需经椭球体与大地水准面之间差异的校正（n值校正，n-value correction），以生成相对于海平面的地形高度。