What is carrier phase ambiguity?

While carrier-phase measurements typically have very low noise compared to pseudorange (code) measurements, they have an inherent integer cycle ambiguity: the carrier phase, interpreted as a range measurement, is ambiguous by any number of cycles.

What is integer ambiguity in GPS?

But because we don’t know the true initial cycle count, the carrier-phase measurements are ambiguous by a constant integer amount (when measured in cycles). This characteristic of the observable is referred to as the integer ambiguity.

What is carrier phase measurement in GPS?

In summary, the carrier phase measurement is a highly precise measure of the pseudorange between satellite and receiver, the generation of useable carrier phase measurements in a receiver requires a phase locked loop, and the receiver designer must take care to ensure that 1) the integer ambiguity term is constant, and …

What is phase ambiguity?

Phase ambiguity is produced by an interaction between ITD magnitude and sound frequency. (A) Phase ambiguity occurs because it is unclear whether the waveform in the right ear (grey) is delayed (ΔΦ1) or advanced (ΔΦ2) with respect to the waveform in the left ear (black).

What is the three carrier ambiguity resolution?

The technique is based on the use of three modulated carriers which theoretically allow to reduce the number of candidate points of the ambiguity to only one, hence making extremely precise navigation possible in real-time.

What is carrier phase ambiguity resolution?

Carrier phase ambiguity resolution is the key to high precision Global Navigation Satellite System (GNSS) positioning and navigation. Finally the probability density function of the ambiguity residuals is determined. This allows one for the first time to formulate rigorous tests for the integerness of the parameters.

What is ambiguity resolution in GPS?

GPS ambiguity resolution is the process of resolving the unknown cycle ambiguities of double-difference (DD) carrier-phase data as integers. It is the key to fast and high-precision relative GPS positioning. Critical in the application of ambiguity resolution is its reliability.

How ambiguity in a position line is resolved?

The method of multiple lines of position introduced herein uses signals from four or more Omega stations for ambiguity resolution. Subsequently, a likelihood function is generated for each point, and the ambiguity is resolved by selecting the most likely point.

What is the difference between code phase and carrier phase GPS?

Carrier phase- GPS measurements based on the L1 or L2 carrier signal. Carrier- A signal that can be varied from a known reference by modulation. Code phase GPS- GPS measurements based on the pseudo random code (C/A or P) as opposed to the carrier of that code.

What causes range ambiguity?

In Synthetic Aperture Radar (SAR) imaging, range ambiguity is caused by the echoes of the previous and latter transmitted pulses scattered from undesired range zones [1].

What causes range ambiguity in ultrasound?

Range ambiguity occurs more often when a relatively high PRF is used. Range ambiguity may be used for mapping of abnormal flow beyond the range of PW or for recording of high velocities at sample volumes far from the transducer without frequency aliasing.

What is carrier phase shift?

Carrier Phase Shift Modulation for Reducing the Common Mode Voltage in a Two-Level Three-Phase Inverter. The reduction in CMV is necessary to limit the Common Mode Currents (CMC) which in turn reduces the inverter induced bearing currents and shaft voltage.

How is integer ambiguity fixing used in GPS?

However, integer ambiguity fixing is now routinely applied to undifferenced GPS carrier-phase measurements to achieve precise positioning. Some implementations are even available in real time. This so-called precise point positioning (PPP) technique permits ambiguity resolution at the centimeter level.

How is ambiguity resolved in carrier phase measurements?

But there is a catch to the use of carrier-phase measurements: they are ambiguous by an integer multiple of one cycle. Processing algorithms must resolve the value of this ambiguity and ideally fix it at its correct integer value.

How are carrier phase measurements used in GPS?

However, by using precise products and a very thorough model of the GPS observables, the PPP technique does away with the requirement for a directly accessed base station. The other precision aspect of PPP is its use of carrier-phase measurements rather than just pseudoranges.

What’s the difference between carrier phase and pseudorange?

While carrier-phase measurements typically have very low noise compared to pseudorange (code) measurements, they have an inherent integer cycle ambiguity: the carrier phase, interpreted as a range measurement, is ambiguous by any number of cycles.