The accuracy of sea surface parameters retrieved from altimeter missions is predominantly governed by the choice so-called “retracking” algorithm, i.e., model and inversion method implemented to obtain backscattered waveform. For continuity reasons, space agencies usually apply same retracker one satellite mission other ensure long-time homogeneous series. In this article, taking opportunity a ...

Access to fresh water is a key issue for the next decades in context of global warming. The level lakes fundamental variable that needs be monitored this purpose. radar altimetry constellation brings worldwide means question. Recent advances altimeter onboard tracking modes have allowed monitoring thousands and rivers. Now, measurements are widely available with better resolution: it time drast...

A size-segregated aerosol dynamics model UHMA (University of Helsinki Multicomponent Aerosol model) was developed for studies of multicomponent tropospheric aerosol particles. The model includes major aerosol microphysical processes in the atmosphere with a focus on new particle formation and growth; thus it incorporates particle coagulation and multicomponent condensation, applying a revised t...

Lake levels in the Qinghai-Tibet Plateau (QTP) provide valuable records for climate change studies. We use two decades of measurements (January 1993–December 2014) from the TOPEX/Poseidon (T/P)-family satellite altimeters (T/P, Jason-1 and -2) to detect lake level variations at 23 lakes along their repeat ground tracks every 10 days. We employ an optimal processing technique to obtain quality m...

The scattering of GNSS signals over a water surface is studied when the receiver is at a low height, as in GNSS-R coastal altimetry. The precise determination of the local sea level and wave state from the coast will provide useful altimetry and wave information as “dry” tide and wave gauges. An experiment has been conducted at the Canal d'Investigació i Experimentació Marítima (CIEM) wave chan...

Spaceborne Global Navigation Satellite System-Reflectometry (GNSS-R) has been the research focus of Earth observation because of its unique advantages; however, there are still many challenges to be resolved. The reduction of the impact of the satellite motion on the GNSS-R waveform is the one of key technologies for spaceborne GNSS-R. The proposed delay retracking methods in existing literatur...

The capability of satellite radar altimeters to monitor the height changes of major lakes is well established. However, river systems present far more challenging targets. By retracking altimeter echoes using an expert system approach, river heights can be successfully monitored; this capability is bounded by the along-track sampling rate. However, a glimpse into the potential of future altimet...

It is widely believed that altimetry-derived sea surface heights (SSHs) in coastal zones are seriously degraded due to land contamination in altimeter waveforms from non-marine surfaces or due to inhomogeneous sea state conditions. Spurious peaks superimposed in radar waveforms adversely impact waveform retracking and hence require tailored algorithms to mitigate this problem. Here, we present ...