The Effects of Rain on Topex Radar Altimeter Data

Quartly, Graham D.; Guymer, T. H.; Srokosz, Meric

doi:10.1175/1520-0426(1996)013<1209:teorot>2.0.co;2

Cited by 64 publications

(69 citation statements)

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“…AltiKa echoes are attenuated and distorted by rain events of heavy clouds [38][39][40], as shown in Figure 19a. The waveform amplitude is not only strongly attenuated but its shape is distorted, especially on the trailing edge part of the waveform.…”

Section: Impact Of Rain On Saral/altika Measurements a New Opportunimentioning

confidence: 99%

The Benefits of the Ka-Band as Evidenced from the SARAL/AltiKa Altimetric Mission: Quality Assessment and Unique Characteristics of AltiKa Data

et al. 2018

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Abstract:The India-France SARAL/AltiKa mission is the first Ka-band altimetric mission dedicated to oceanography. The mission objectives are primarily the observation of the oceanic mesoscales but also include coastal oceanography, global and regional sea level monitoring, data assimilation, and operational oceanography. The mission ended its nominal phase after 3 years in orbit and began a new phase (drifting orbit) in July 2016. The objective of this paper is to provide a state of the art of the achievements of the SARAL/AltiKa mission in terms of quality assessment and unique characteristics of AltiKa data. It shows that the AltiKa data have similar accuracy at the centimeter level in term of absolute water level whatever the method (from local to global) and the type of water surfaces (ocean and lakes). It shows also that beyond the fact that AltiKa data quality meets the expectations and initial mission requirements, the unique characteristics of the altimeter and the Ka-band offer unique contributions in fields that were previously not fully foreseen.

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Section: Impact Of Rain On Saral/altika Measurements a New Opportunimentioning

confidence: 99%

The Benefits of the Ka-Band as Evidenced from the SARAL/AltiKa Altimetric Mission: Quality Assessment and Unique Characteristics of AltiKa Data

et al. 2018

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“…The highly correlated σ 0 observations at K u -and C-band are key to techniques to develop rain-flagging and rain-rate quantification from altimeter data (Quartly et al 1996, Quartly et al 1999Tournadre 2006). Figure 4 shows the envelope of simultaneous dual-frequency observations for Jason-1 (indicated by mean and dashed lines for ±2 standard deviations).…”

Section: Long-term σ 0 Monitoringmentioning

confidence: 99%

“…Furthermore the different signal backscatter strengths at K u -band and C-band have been used in rain detection algorithms (Quartly et al 1996;Quartly 2004;Tournadre 2004) and in estimating air-sea gas transfer (Frew et al 2007). In order to ensure that possible long-term trends associated with climate change can be detected, it is important to assess any difference in performance between the two altimeters, as well as monitoring for any gradual degradation once the cal/val period is over.…”

Section: Introductionmentioning

confidence: 99%

Jason-1/Jason-2 Metocean Comparisons and Monitoring

Quartly

2010

Marine Geodesy

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The initial tandem phase of the Jason-2 mission is important for the calibration of the entire altimetric system, not just the records of sea surface height. However, as well as allowing a bulk comparison of metocean parameters such as wave height and backscatter strength (used to infer wind speed), it affords a more detailed opportunity to understand the artefacts within each instrument. The wave height comparison shows no bias between the instruments, with the mismatch error of consecutive points independent of one another. The backscatter difference is not a simple offset, but has a trend with weak non-linear variations. The technique for backscatter monitoring using K u -/C-band differences is validated during the tandem phase, and extended to show 59-day oscillations in Jason-1 data, probably associated with spacecraft manoeuvres.

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“…The benefit of this method is illustrated in Fig. 3, using data from the TOPography EXperiment altimeter (Quartly et al 1996(Quartly et al , 1999. The black dashed line shows the surface roughness observed by C-band (5.3 GHz), but rescaled to show the value to be expected at K u -band (13.6 GHz).…”

Section: Active Microwave Sensorsmentioning

confidence: 99%