Scanning laser wave recorder with registration of “instantaneous” sea surface profiles

A direct optical method for measuring the “instantaneous” profile of the sea surface with an accuracy of 1 mm and a spatial resolution of 3 mm is described. Surface profile measurements can be carried out on spatial scales from units of millimeters to units of meters with an averaging time of 10−4 s. The method is based on the synchronization of the beginning of scanning a laser beam over the sea surface and the beginning of recording the radiation scattered on the surface onto the video camera matrix. The heights of all points of the profile are brought to a single point in time, which makes it possible to obtain “instantaneous” profiles of the sea surface with the frequency of video recording. The measurement technique and data processing algorithm are described. The errors of the method are substantiated. The results of field measurements of the parameters of sea waves are presented: amplitude spectra, distribution of slopes at various spatial averaging scales. The applied version of the wave recorder did not allow recording capillary oscillations, but with some modernization it will be possible. The method is completely remote, does not distort the properties of the surface, is not affected by wind, waves and sea currents, it allows you to measure the proportion of foam on the surface. The possibility of applying the proposed method at any time of the day and in a wide range of weather conditions has been experimentally proved.

Environmental conditions of a salt-marsh biodiversity experiment on the island of Spiekeroog (Germany)

Field experiments investigating biodiversity and ecosystem functioning require observation of abiotic parameters, especially when carried out in the intertidal zone. An experiment for biodiversity-ecosystem functioning at the intersection of land and sea was set up in the intertidal zone of the back-barrier salt marsh of Spiekeroog Island in the German Bight. Here we report the accompanying instrumentation, maintenance, data acquisition, data handling and data quality control as well as monitoring results observed over a continuous period from September 2014 through April 2017. Time series of abiotic conditions were measured at several sites in the vicinity of newly built experimental "salt-marsh islands" on the tidal flat. Meteorological measurements were conducted from a weather station (WS, doi:10.1594/PANGAEA.870988), oceanographic conditions were sampled through a bottom mounted recording current meter (RCM, doi:10.1594/PANGAEA.877265) and a bottom mounted tide and wave recorder (TWR, doi:10.1594/PANGAEA.877258). Tide data are essential to calculate flooding duration and flooding frequency with respect to different salt marsh elevation zones. Data loggers (DL) for measuring water level (DL-W, doi:10.1594/PANGAEA.877267), temperature (DL-T, doi:10.1594/PANGAEA.877257), light intensity (DL-L, doi:10.1594/PANGAEA.877256) and conductivity (DL-C, doi:10.1594/PANGAEA.877266) were deployed at different elevational zones within the experimental islands and the investigated salt marsh plots.

Design of a Fault Diagnosis Model for Power System with Based on Multi-Source Information Fusion

In view of inherent insufficiency of traditional power grid fault diagnoses expert system inthe aspect of knowledge acquisition,together with the characteristics of decision tree algorithm andexpert system, this paper puts forward a new power gird fault diagnoses expert system model basedon multi-source information fusion with SCADA switch, fault wave recorder electric quantity andWAMS system of electric quantity.On this foundation,we discuss the reasoning mechanism forpower gird, the reasoning algorithm, and the method of knowledge acquisition of the model. Thepractice results show that this proposed new approach improves the diagnostic accuracy comparedwith the conventional way based merely on switching-time data,and has practical value and goodapplication prospects.