The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The sea state bias (SSB) has become the dominant source of error in satellite altimetry. The operational SSB correction models are two-dimensional (2-D) nonparametric models based on the wind speed (U) and the significant wave height (SWH) that can be directly measured by the altimeters. This paper estimates the sea state bias of HY-2A radar altimeter using a three-dimensional (3-D) nonparametric...
Altimeter provides a unique perspective to observe global ocean frequently which is never happened before. Whereas the altimeter measures the ocean in a narrow track, it is inconvenient in studying the ocean structures such as Kuroshio and Gulf Stream, let alone the mesoscale structures which are important ways to transport mass and energy. These ocean structures determined by sea surface topography...
Since the launch, HY-2A has observing global ocean dynamic environment data over the last 5 years including sea surface height (SSH), significant wave height (SWH) and corresponding auxiliary data (wind fields and water vapor). The in-orbit validation and crossover comparison of which suggest that the various technical indicators cater for basic needs in practicality. However, for the most important...
This paper is aimed to assess the accuracy of HY-2A altimetry system. To further improve the accuracy and performance of HY-2A observed SSHs, several new treatments including 4 parameters maximum likelihood estimation (MLE4) retracking for Ku and C band, non-parameter sea state bias (NPSSB) model, and reprocessed dual-frequency altimeter ionospheric correction are included. The evaluation from dual-crossover...
Water vapor and cloud liquid water can influence the accuracy of sea surface height that spaceborne altimeter measures. Atmospheric correction microwave radiometer (ACMR) can be used to retrieve the amount of water vapor and cloud liquid water by measuring radiation from atmosphere and earth's surface. HY-2 satellite is a Chinese satellite for ocean dynamic environmental monitoring. ACMR is one payload...
This paper presents a result of crossover analysis between HY-2 and Jason-2 mission over ocean. The major objectives of this paper are to assess HY-2 IGDR (Interim Geophysical Data Record) derived SSHs by comparing HY-2 measurements with the reference mission Jason-2, and further to illustrate the potential of HY-2 data in monitoring global sea level variability. The instrument-independent models...
In this paper, a improved inertial frame alignment algorithm is proposed, which significantly improves the accuracy and time cost of the traditional inertial frame coarse alignment algorithm. Firstly, a dimensionality reduction Gauss-Hermite filter algorithm is employed in the horizontal fine alignment phase. Secondly, according to the feature of the gravity, that the horizontal components of the...
Cooperative localization (CL) plays an important role in the application of multiple autonomous underwater vehicles (AUVs) simultaneously, by communicating with each other through acoustic modems on-board, which can not only increase the navigation performance but also reduce the navigation cost. Compared to one-way-ranging (OWR) based on precise time synchronized, the round-trip ranging (RTR) is...
Design an electrical locomotive 110 V D.C. source with PFC based on the structure of two-stage switching converter. Discuss the design scheme of main circuit and control circuit. Expound the calculation method of the key parameters. The experiments indicate that the device gets good performance on output and reliability. The electric source is appropriate for electrical locomotive and the other similar...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.