Limits...
Precise Point Positioning with Partial Ambiguity Fixing.

Li P, Zhang X - Sensors (Basel) (2015)

Bottom Line: Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate.Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP.Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate.

View Article: PubMed Central - PubMed

Affiliation: School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, Wuhan 430079, China. lipan.whu@gmail.com.

ABSTRACT
Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate.

No MeSH data available.


Related in: MedlinePlus

The average RMS of station position in east, north and up directions for kinematic PPP with the FAR and PAR methods.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4507701&req=5

sensors-15-13627-f012: The average RMS of station position in east, north and up directions for kinematic PPP with the FAR and PAR methods.

Mentions: We have calculated the average RMS of all test sessions (see Figure 12). The RMS can be reduced by 17.6%, 5.7% and 9.0% (from 13.6, 10.6 and 32.3mm to 11.2, 10.0 and 29.4 mm in east, north and vertical) when the PAR method is applied to the same data set. It should be noted that the accuracy of the east component is considerably worse than that of the north component for FAR. The reason is that the integer ambiguity cannot be correctly resolved in some epochs, which results in a float solution. Generally speaking, the accuracy of the east component is lower than that of north component for a PPP float solution [7].


Precise Point Positioning with Partial Ambiguity Fixing.

Li P, Zhang X - Sensors (Basel) (2015)

The average RMS of station position in east, north and up directions for kinematic PPP with the FAR and PAR methods.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507701&req=5

sensors-15-13627-f012: The average RMS of station position in east, north and up directions for kinematic PPP with the FAR and PAR methods.
Mentions: We have calculated the average RMS of all test sessions (see Figure 12). The RMS can be reduced by 17.6%, 5.7% and 9.0% (from 13.6, 10.6 and 32.3mm to 11.2, 10.0 and 29.4 mm in east, north and vertical) when the PAR method is applied to the same data set. It should be noted that the accuracy of the east component is considerably worse than that of the north component for FAR. The reason is that the integer ambiguity cannot be correctly resolved in some epochs, which results in a float solution. Generally speaking, the accuracy of the east component is lower than that of north component for a PPP float solution [7].

Bottom Line: Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate.Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP.Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate.

View Article: PubMed Central - PubMed

Affiliation: School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, Wuhan 430079, China. lipan.whu@gmail.com.

ABSTRACT
Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate.

No MeSH data available.


Related in: MedlinePlus