Absolute calibration of satellite altimetry using linear regression and harmonic analysis

Abstract

The calibration of satellite radar altimetry has been extremely important for altimetry community and studying sea level changes. The main purpose of this contribution is to provide ongoing absolute calibration of altimeter bias near the Southern seas of Iran using the Iranian tide gauge network that equipped with GPS receivers to measure the sea surface heights synchronously in the same geocentric reference frame as the corresponding altimetry records. The sea level time series of coastal tide gauges have been used to estimate the bias, drift and annual/semiannual constituents of altimeter range measurements using (i) linear regression and (ii) combination of linear regression and harmonic analysis. To this end, three Iranian tide gauges located at Bushehr, Bandar Abbas and Chahbahar ports as well as Geophysical Data Records (GDR) products of Topex/Poseidon, Jason-1and Jason-2 have been considered. The numerical results have indicated that the mean absolute biases of Topex/Poseidon, Jason-1 and Jason-2 are about –26.23, 120.21 and 205.17 mm, respectively. The reliability of method has been assessed via GPS vessel at the altimeter bin nearby the Bushehr tidal stations. The presented method is viable to perfectly estimate the systematic errors, and as such, it can address the demands of high-accurate applications.

Keywords:

• altimeter calibration
• absolute bias
• tide gauges
• Topex/Poseidon
• Jason-1
• Jason-2
• Persian Gulf and Oman Sea

Additional information

Notes on contributors

Iraj Jazireeyan

Iraj JAZIREEYAN is lecturer of Faculty of Geodesy and Geomatics Engeeniering of Khaje Nasir Toosi University of Technology and the student of PhD in the field of geodesy at the Tehran University. Also he has published more than 21 scientific journal and conference papers.

Alireza A. Ardalan

Alireza A. ARDALAN is full professor of Survey Engineering and Geodesy at the Department of Surveying and Geomatics Eng. of the University of Tehran, he has got his PhD in the field of geodesy at the Stuttgart University, he had supervised more than 63 Master and 15 PhD theses, and published more than 89 scientific journal papers.