25.07.2013 Views

Antti Lehtinen Doppler Positioning with GPS - Matematiikan laitos

Antti Lehtinen Doppler Positioning with GPS - Matematiikan laitos

Antti Lehtinen Doppler Positioning with GPS - Matematiikan laitos

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

3.4 <strong>Positioning</strong>ErrorAnalysis ...................... 13<br />

3.5 Limitationsofthe<strong>GPS</strong>........................ 14<br />

4 <strong>Doppler</strong> <strong>Positioning</strong> <strong>with</strong> the <strong>GPS</strong> 16<br />

4.1 Needfor<strong>Doppler</strong><strong>Positioning</strong>..................... 16<br />

4.2 Comparisonbetween<strong>GPS</strong>andTransit ............... 17<br />

4.3 TheGoverningEquations ...................... 18<br />

4.3.1 The<strong>Doppler</strong>ShiftEquation ................. 18<br />

4.3.2 TheClockDriftError .................... 20<br />

4.3.3 Mathematical Problem Formulation . . . . . . . . . . . . . 21<br />

4.4 SymbolicMethods .......................... 23<br />

4.4.1 Solvingthe Receiver Position . . . . . . . . . . . . . . . . 23<br />

4.4.2 Existence and Uniqueness Considerations . . . . . . . . . . 23<br />

4.5 StandardNumericalMethods .................... 24<br />

4.5.1 ProblemFormulation..................... 24<br />

4.5.2 TheNewtonMethod ..................... 25<br />

4.5.3 TheGauss-NewtonMethod ................. 26<br />

4.5.4 CalculatingtheDerivativeMatrix.............. 27<br />

4.6 ProblemSpecificIterativeMethods ................. 30<br />

5 <strong>Positioning</strong> Performance 31<br />

5.1 MeasurementNoise.......................... 31<br />

5.1.1 IonosphericEffects ...................... 31<br />

5.1.2 Receiver Noise . . . . . . . . . . . . . . . . . . . . . . . . . 32<br />

5.1.3 UnknownUserVelocity.................... 32<br />

5.1.4 BiasedTimeEstimate .................... 34<br />

5.2 <strong>Positioning</strong>Accuracy......................... 35<br />

5.2.1 Effect of Measurement Errors on <strong>Positioning</strong>Solution . . . 35<br />

5.2.2 <strong>Doppler</strong> Dilution of Precision . . . . . . . . . . . . . . . . 36<br />

iii

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!