Code pseudoranges e when a gPs receiver measures the time offset it needs to apply to its replica of the code to reach maximum correlation with received signal what is it measuring? It is measuring the time difference between when a signal was transmitted(based on satellite clock and when it was received(based on receiver clock) If the satellite and receiver clocks were synchronized, this would be a measure of range Since they are not synchronized, it is called pseudornage wy Principles of the Global Positioning System 2005-325(5) Code pseudoranges Pseudorange R=(t C Where R is the pseudorange between receiver R and satellite S; tR is the receiver clock time. t is the satellite transmit time and c is the This expression can be related to the true range by introducing t=rR+△tt=r3+△ t Rand r are true times; Atg and 4N are clock corrections wEI Principles of the Global Positioning System 20053-25(63 Principles of the Global Positioning System 2005-3-25 5 Code pseudoranges ‹ When a GPS receiver measures the time offset it needs to apply to its replica of the code to reach maximum correlation with received signal, what is it measuring? ‹ It is measuring the time difference between when a signal was transmitted (based on satellite clock) and when it was received (based on receiver clock). ‹ If the satellite and receiver clocks were synchronized, this would be a measure of range ‹ Since they are not synchronized, it is called “pseudornage” Principles of the Global Positioning System 2005-3-25 6 Code pseudoranges Pseudorange: R t t c S R = ( − )⋅ Where R is the pseudorange between receiver R and satellite S; tR is the receiver clock time, t S is the satellite transmit time; and c is the speed of light This expression can be related to the true range by introducing corrections to the clock times S S S R R R t =τ + ∆t t =τ + ∆t τR and τS are true times; ΔtR and Δt S are clock corrections