He is currently working at the L.E.S.I.M. Laboratory, Department of Engineering, Sannio University, where he is a postdoctoral researcher in the field of electrical and electronic measurements. The use of SAR satellite sensors has been limited in the past due to the low spatial resolution of the images [30,31].
Methodology
In the presence of waves, the values of the backscattering coefficient (σ0) are much higher than in calm conditions. The available orthophotos are therefore used to adjust the amplitude and coherence thresholds to be configured in the coastal classification process.
Case Studies
The second experimental case study (Test Site II) is located along a very popular beach (Bacino Grande) in the southern part of the municipality of Porto Cesareo. Since 2006, the area of interest has been continuously monitored by the SIMOP network, which includes: (i) an anemometric station, (ii) a tide gauge located a few hundred meters to the south and (iii) a wave buoy moored offshore in the Gulf of Taranto, about 60 km north of Porto Cesareo.
Results
Within the in situ campaigns, regularly spaced bank-perpendicular transects were inventoried and the 0 m contour was extrapolated. The overall performance of the LGDF algorithm has been estimated using a range of statistical indicators.
Discussion
The main limitation of the presented integrated approach is related to the nature of the radar data. The proposed procedure for beach monitoring can also be effectively extended to SAR data provided by other European Space Agency missions launched in the framework of the Copernicus Earth Observation programme.
Conclusions
In Proceedings of the International Workshop on Metrology for the Sea (MetroSea 2018), Bari, Italy, 8-10 October 2018; pp. In Proceedings of the EUSAR 2014; 10th European Conference on Synthetic Aperture Radar, Berlin, Germany, 3-5 June 2014; pp.
Monitoring for Coastal Resilience: Preliminary Data from Five Italian Sandy Beaches †
- Introduction
- Materials and Methods 1. Study Sites
- Results
- Discussion and Conclusions
The remotely sensed locations of the coastline and the column are shown with the orange and black lines, respectively. As a consequence of the physiographic differences between the Adriatic and Tyrrhenian basins (elongated and closed the former, more open the latter), the wave bias in the Adriatic areas is clearly bimodal (due to the effect of the local Scirocco and Bora winds), while the incidence distribution for Tyrrhenian sites is mainly unimodal (Figure 3).
Monitoring Systems and Numerical Models to Study Coastal Sites †
- Materials and Methods
- Numerical Modelling 1. Calibration
- Results and Discussion
- Conclusions
The oil spill model has been driven by output from the calibrated hydrodynamic model MIKE 3FM for T1 and T2 cases respectively. In the winter case (T1), the selected period of the race is characterized by mainly NW and NE winds. In the summer case (T2), the chosen period of the race is characterized by very variable winds.
The oil is displaced and spread towards the northern border of the basin, in the harbor area. Thus, in this case, the oil slick tends to return to the center of the basin. The oil spill model is driven by the results of the calibrated MIKE 3FM hydrodynamic model.
Emergent Vegetation †
Experimental Setup
A triangular, sharp-shaped weir at the downstream reservoir is used to estimate the steady-state flow rate, whereas a more accurate measure of the flow rate from the secondary reservoir is provided by an electromagnetic flowmeter, located upstream of the channel. The water level at the end of the river is controlled by a sloping (1:50) gravel beach. During the ADVs' measurements, a correlation of the signal around 90% and a signal-to-noise ratio around 12 dB are achieved, which proves the good quality of the signal itself.
Figure 1 shows that the three ADV measurement systems are located in the canopy at the same position of the ultrasonic probes, i.e. x=7.50 m, 9.00 m, 10.50 m, to obtain simultaneous water level and velocity measurements. The PIV sampling rate is set to its maximum (i.e. 16 Hz), while the time interval between two images of the same pair is 500 μs. Thus, the total acquisition time is 24 s for each measurement in the target region of the channel.
Results and Discussion
Spatial variations of wave height under bare ground conditions (ie, no vegetation) is shown in Figure 4b. Experimental results referring to vegetation scenarios show that canopy density strongly affects the spatial attenuation of wave peak. Figure 7 shows a comparison between vertical velocity profiles along x=9.00 m channel axis, under bare conditions and with vegetation density=156.25 cylinder/m2, both during base flow and peak wave conditions.
In Figure 8, we report the transverse profiles of the longitudinal velocity u behind a cylinder located in the middle of the array with a vegetation density of n = 156.25 cylinder/m2, between baseflow and wave crest conditions. The origin of the local reference system (xc, yc) coincides with the center of the cylinder represented by the red dot (inset of panel (a)). The flow velocity field obtained by the PIV technique confirms the latter result.
Conclusions
During base flow conditions, the vertical velocity profile clearly showed a logarithmic profile in bare soil, while changing to a fairly uniform velocity distribution in the presence of vegetation, in agreement with many previous works (i.e. [40]). A wake area was observed downstream of the cylinder banks, where a significant reduction in speed was observed both during the base flow and at the wave peak, in this second case even more. In fact, the field of the vorticity map at the wave peak also clearly showed the coexistence of two intense opposing vortices downstream of the cylinder, with vorticity values nearly four times greater than those estimated for the base current condition.
The main aspects of the interaction between wave and vegetation can be fully obtained thanks to such a complete measurement system. However, the combined use of the various adopted sensors and techniques still has unexpressed potential in the cutting-edge investigation of this phenomenon and deserves further analysis. Laboratory and numerical studies of wave attenuation by emergent and near-emergent wetland vegetation.Coast.
New Approach to Analysis of Selected Measurement and Monitoring Systems Solutions in
Ship Technology
The Role of Measurement in the Ship’s Operation Process
Measurement of parameters characterizing the ship's movement (determination of velocity vector, heading, draft, trim, side sway of the ship, wind direction and force). Measurement of parameters, generally temperatures, pressures, levels, viscosity and flows at selected points that determine the operating conditions of the power plant. Measurement of torque, power and rotational speed on the main engine shaft (ME) with a view to economic operation of the ship's propulsion.
The purpose of operational measurement is to determine the current value of the parameters of a given system and check the correctness of its operation and related processes. Operational measurement is used for both manual and automatic remote control, and its main purpose is the safe and efficient operation of the ship. Local control of the main engine or local control of the rudder are examples of such a solution.
A Short Overview of Selected Examples of Measuring and Monitoring Systems on Sea Ships Measurement methods in marine technology have passed from the model of direct and indirect
The SeaPerformer system measures the torque on the shaft and revolutions (RPM- Revolution Per Minute) of the main engine. Based on the state-of-the-art measurement of torque can be performed using the measurement of the torsion angle ϕ of the propeller shaft during operation of the engine. As an illustration of the discussed problem, the measurement of temperature in the tank of a gas tanker is presented.
The general scheme of placing the tanks and measuring the corresponding temperature is shown in Figure 8. To analyze the above circuit, a small signal model of the measuring line is shown in Figure 11. Results of Validation Tests of the ETNP-10 Motion Control Assist System installed on the propeller shaft;.
Optimization of the Maritime Signaling System in the Lagoon of Venice †
- Classic AtoN System
- An Overview on the AIS
- Navigate with Virtual AtoN
- Final Application
These tasks mainly concern the improvement of communication systems (in particular the portfolio of ship traffic service, not limited to coastal stations) and the design of the bridge and its equipment, to increase its reliability and resilience and to make the interface more user-friendly [4]. Due to the urgency of a solution, we decided to directly assess the current situation of the signaling system in the Lagoon through an elementary simulation. We proposed to install yellow flashing lights on the entrance lights of the Port, which would be simultaneously activated on the MOSE gates.
The same was proposed in the area of Malamocco, where the main fairway turns to the right of the St. To verify the integrity of the system with respect to the maneuvering aspect, different improved methods can be introduced. Funding: This research was funded by the Port Authority System of the Northern Adriatic Sea (grant number CIGZ851E17165).
Signal in Space Error and Ephemeris Validity Time Evaluation of Milena and Doresa Galileo Satellites †
Materials and Methods 1. Methodology
Its analytical expression can be derived from the orbit error components of the Galileo satellite expressed in along-track (A), cross-track (C) and radial (R) frame and its total Signal In Space (SIS) clock prediction error (CLK) using the following formula. The next step consisted in determining the position and velocity of the satellites for each epoch from precise orbital parameters. In the figures, it is clear how setting the ephemeris validity time equal to 1800 makes it possible to obtain a SISEorbit comparable to that of the other satellites.
This effect does not occur on the other satellites for which the improvement of the SISEorbit with the reduction of the validity time is negligible. If a validity time of 1800 or 900 s is used, Milena (E14) and Doresa (E18) achieve a SISEorbitRMS of about 1 m comparable to that of the other Galileo satellites. If a validity time of 900 s is used, the discard epochs are about 30% of the total.
Discussion
This aspect will be discussed in a forthcoming publication, which the authors are already working on. Acknowledgments: The authors gratefully acknowledge the IGS MultiGNSS Experiment (MGEX) for providing GNSS data and products. In Proceedings of the 25th International Symposium on Space Flight Dynamics ISSFD, Munich, Germany, 19-23 October 2015.
Validation of Galileo orbits using SLR with focus on satellites launched into wrong orbital planes. On the utility of Galileo FOC satellites with irregular highly eccentric orbits: an assessment of current medium-range positioning. In Proceedings of the 2nd IEEE International Workshop on Metrology for the Sea, Bari, Italy, 8–10 October 2018.
