Notes of code pseudoranges corrections ap plied for propagation delays becauange and The equation for the pseudorange uses the true se the propagation velocity is not the in-vacuum value, c, 299792458x108m/s e To convert times to distance c is used and then corrections applied for the actual velocity not equaling c. In rinEX data files, pseudorange is given in distance units The true range is related to the positions of the ground receiver and satellite e Also need to account for noise in measurements p-code pseudoranges can be as good as 20 cm or less, while the LI C/A code range noise level reaches even a meter or more Principles of the Global Positioning System 2005-3-25(9) hase pseudoranges Carrier phase- a difference between the phases of a carrier signal received from a spacecraft and a reference signal generated by the receivers internal oscillator e contains the unknown integer ambiguity N. i.e. the number of phase cycles at the starting epoch that remains constant as long as the tracking is continuous phase cycle slip or loss of lock introduces a new ambiguity unknown typical noise of phase measurements is generally of the order of a few millimeters or less EX Principles of the Global Positioning System 55 Principles of the Global Positioning System 2005-3-25 9 Notes of code pseudoranges ‹ The equation for the pseudorange uses the true range and corrections applied for propagation delays because the propagation velocity is not the in-vacuum value, c, 2.99792458x108 m/s ‹ To convert times to distance c is used and then corrections applied for the actual velocity not equaling c. In RINEX data files, pseudorange is given in distance units. ‹ The true range is related to the positions of the ground receiver and satellite. ‹ Also need to account for noise in measurements. P-code pseudoranges can be as good as 20 cm good as 20 cm or less, while the L1 C/A code range noise level reaches even a meter or more meter or more . Principles of the Global Positioning System 2005-3-25 10 Phase pseudoranges ‹ Carrier phase - a difference between the phases of a carrier signal received from a spacecraft and a reference signal generated by the receiver’s internal oscillator ‹ contains the unknown integer ambiguity, N unknown integer ambiguity, N, i.e., the number of phase cycles at the starting epoch that remains constant as long as the tracking is continuous ‹ phase cycle slip cycle slip or loss of lock loss of lock introduces a new ambiguity unknown. ‹ typical noise of phase measurements is generally of the order of a few millimeters or less