ABSTRACT
The understanding and management of errors is indispensable for finding the true geometric range ρ from either a pseudorange or a carrier phase observation.
p d c dt dT d d mp p= + + − + + + +ρ ε ερ ( ) ion trop (pseudorange)
φ ρ λ ε ερ φ φ= + + − + − + + +d c dt dT N d d m( ) ion trop (carrier phase)
Both equations include environmental and physical limitations called range biases. Atmospheric errors are among the biases; two are the ionospheric effect dion
and the tropospheric effect dtrop. The tropospheric effect may be somewhat familiar to total station and electronic distance measuring (EDM) device users, even if the ionospheric effect is not. Other biases, clock errors symbolized by (dt – dT) and receiver noise (εp and εϕ), multipath (εmp and εmϕ), and orbital errors dρ are unique to satellite surveying methods. As you can see, each of these biases comes from a different source. They are each independent of one another, but they combine to obscure the true geometric range. The objective here is to discuss each of them separately.
