References
Lustrumboek "The 5th Element"
of the ambiguities becomes singular. As a consequence, the success rate reduces
to zero.
1400 1500 1600 1700
Second frequency [MHz]
1400 1500 1600
Third frequency [MHz]
Figure 4. The long baselinesingle epochdual-frequency ambiguity success rate as function
of the second frequency at left and the corresponding triple-frequency ambiguity success
rate as function of the third frequency at right. For the dual-frequency casethe first frequency
was fixed at the GPS LI value and for the triple-frequency casethe first two frequencies
were fixed at the GPS LI and L2 values. The dashed vertical lines indicate the current Ll-
and L2-frequency/ as well as the chosen third GPS frequency.
We will now consider the triple-frequency case. Figure 4, at right, shows the long
baseline, single epoch, triple-frequency, ambiguity success rate as function of a
vamng third frequency. The first two frequencies were fixed at the GPS LI and L2
Vu- jiS' When comPare to f'9ure 4, at left, the figure shows that the addition of a
third frequency indeed improves the success rate. The maximum value is about
10 times larger. The success rates however, are still too small for single epoch
ambiguity resolution to be successful. This not only holds true for modernized
GPS, tor which the third frequency equals the L3 value. It would hold true for any
triple-frequency system for which the third frequency lies in the frequency range
shown. The conclusion reads therefore that, although one can significantly improve
upon the third frequency choice of modernized GPS, the improvement will still
not make successful instantaneous long baseline ambiguity resolution feasible.
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[2] Jonkman, N.F.PJ.G. Teunissen, R Joosten and D. Odijk, GNSS long baseline
ambiguity resolution: impact of a third navigation frequency, In: Geodesy
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Vol. I 21, Birmingham, July 19-30 (1999), Birmingham, UK, 1999, p.
34 9~354
[3] Teunissen, PJ.G., An opti ma I ity property of the integer least-squares estimator.
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[4] Teunissen, PJ.G., Least-squares estimation of the integer ambiguities. IAG
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[5] Teunissen, PJ.G., Success probability of integer GPS ambiguity rounding
and bootstrapping, Journal of Geodesy, 72, 1 998, p. 606-61 2.
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