If you wish to contribute or participate in the discussions about articles you are invited to contact the Editor

Ionosphere-free Combination for Dual Frequency Receivers: Difference between revisions

From Navipedia
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
{{Article Infobox2
{{Article Infobox2
|Category=Fundamentals
|Category=Fundamentals
|Authors=J. Sanz Subirana, JM. Juan Zornoza and M. Hernandez-Pajares, University of Catalunia, Spain.
|Authors=J. Sanz Subirana, J.M. Juan Zornoza and M. Hernández-Pajares, Technical University of Catalonia, Spain.
|Level=Basic
|Level=Basic
|YearOfPublication=2011
|YearOfPublication=2011
Line 7: Line 7:
|Title={{PAGENAME}}
|Title={{PAGENAME}}
}}
}}
According to the phase and code [[Ionospheric Delay|ionospheric refraction]], the first order ionospheric effects on code <math>R_{P}</math> and carrier-phase <math>\Phi_L</math> measurements depend (99.9%) on the inverse of squared signal frequency <math>f</math>. Thence, the dual-frequency receivers can eliminate its effect through a linear combination of code or carrier measurements:
According to the phase and code [[Ionospheric Delay|ionospheric refraction]], the first order ionospheric effects on code <math>R_{P}</math> and carrier-phase <math>\Phi_L</math> measurements depend (99.9%) on the inverse of squared signal frequency <math>f</math>. Thence, the dual-frequency receivers can eliminate their effect through a linear combination of code or carrier measurements:





Revision as of 12:47, 6 February 2012


FundamentalsFundamentals
Title Ionosphere-free Combination for Dual Frequency Receivers
Author(s) J. Sanz Subirana, J.M. Juan Zornoza and M. Hernández-Pajares, Technical University of Catalonia, Spain.
Level Basic
Year of Publication 2011
Logo gAGE.png

According to the phase and code ionospheric refraction, the first order ionospheric effects on code [math]\displaystyle{ R_{P} }[/math] and carrier-phase [math]\displaystyle{ \Phi_L }[/math] measurements depend (99.9%) on the inverse of squared signal frequency [math]\displaystyle{ f }[/math]. Thence, the dual-frequency receivers can eliminate their effect through a linear combination of code or carrier measurements:


[math]\displaystyle{ \Phi_{_{\mbox{iono-free}}}=\frac{f_1^2\;\Phi_{_{L_1}}-f_2^2\;\Phi_{_{L_2}}}{f_1^2-f_2^2} }[/math]


[math]\displaystyle{ R_{_{\mbox{iono-free}}}=\frac{f_1^2\;R_{_{P_1}}-f_2^2\;R_{_{P_2}}}{f_1^2-f_2^2} \qquad\mbox{(1)} }[/math]


This combination is named Ionosphere-free (see Combination of GNSS Measurements and Combining Pairs of Signals).

It must be pointed out that the Precise Point Positioning uses code and carrier phase measurements in the ionosphere-free combination to remove the ionospheric refraction, because it is one of the effects more difficult to model accurately. Moreover the TGDs also cancel in this combination and are not needed (being the satellite clocks referred to the ionospheric free combination of such codes, see Combining Pairs of Signals).