| Comparison of Code and Carrier Measurements
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- With code observations, a direct measure of the satellite-receiver range is attained. With carrier observations, the ambiguity term (number of whole cycles) must be estimated before one may take advantage of the carrier accuracy. Ambiguity estimation leads to complexities in the use of carrier phase observations which do not exist with code observations. Table 12.1 summarizes characteristics of code and carrire based measurements.
- Carrier wavelengths (19 cm for L1) are much shorter than the C/A code chip length (293 m) and hence can be measured more accurately and used to achieve much higher positional accuracies than code measurements.
The best relative accuracies with code measurements are usually a few meters; with carrier measurement usually a few centimeters.
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| Table 12.1 Comparison of Code and carrier measurements (GPS Positioning Guide 1995)
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Code
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Carrier
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| Advantage
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Non-ambiguous, simple
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High accuracy potential
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| Disadvantage
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Low accuracy
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More complex
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