NeQuick2 is a three-dimensional ionospheric electron density empirical model that uses numerical integration to calculate the total content along any line-of-sight (LOS). As one of most commonly used models, it necessary objectively evaluate accuracy and stability over long period, especially mid-latitudes northern hemisphere where ground-based GNSS stations are distributed. Therefore, differen...

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...

Understanding nodal tidal characteristics is essential for accurate long-term prediction. Observational evolution of tides mainly based on tide gauge records in coastal areas which are limited time and space, thus impeding coherent determinations basin-wide patterns variability. In this paper, we indicate the potential satellite altimeter data to investigate 18.61-year modulations main constitu...

The interferometric imaging radar altimeter (InIRA) aboard the Chinese Tiangong-2 space laboratory is first spaceborne working at low incidence angles. This study focuses on retrieval of significant wave heights (SWHs) from InIRA data. retrieved SWHs can be used for correcting sea state bias InIRA-derived surface and supplement SWH products other sensors. First, we analyzed tilt, range bunching...

The pseudo maximum likelihood estimator allows one to estimate the unknown parameters of Brown’s model for altimeter waveforms. However, the optimality of this estimator, for instance in terms of minimizing the mean square errors of the unknown parameters is not guarantied. Thus it is not clear whether there is some space for developing new estimators for the unknown parameters of altimetric si...