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ALMA MEMO #451

SOME ERROR SOURCES FOR THE PWV AND PATH DELAY ESTIMATED FROM 183 GHZ RADIOMETRIC MEASUREMENTS AT CHAJNANTOR

Guillermo Delgado(Onsala Space Observatory/European Southern Observatory)
Fredrik T Rantakyrö(European Southern Observatory)
Juan Pablo Pérez Beaupuits(European Southern Observatory)
Lars-Åke Nyman (European Southern Observatory/Onsala Space Observatory)

2003/04/02



Keywords: Atmosphere, Phase variations, PWV, pathlength variations

We present here an extensive study of the accuracy of the determination of the PWV from antenna measurements and in the determination of the pathlength variations (and thus phase variations). The study focussed on the effects of instrument measurement effects and software issues. We have also investigated the effect of the water vapour scale height and the presence of water vapour layers in the determination of the path delay. After correcting the software for the instrumental effects and applying empirically determined corrections to the path delay estimates we reached a good agreement between observed path delay variations and the inferred path delay variations determined from the PWV measurements.


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Last modified: 2003-04-10

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