Integrated Geodetic and Hydrographic Measurements of the Yacht Port for Nautical Charts and Dynamic Spatial Presentation

2023

Electronics

Self Cite

Satellite surveying techniques are currently among the main measuring technologies in geodesy and the main technologies in navigation. Modern navigation requires high accuracy of position coordinate determination, particularly in bathymetric surveys and aerial photogrammetry. In most cases, the terrain conditions enable positioning with high accuracy and reliability. These particularly involve the terrain conditions, i.e., high harbour infrastructure for bathymetric surveys and trees for railway surveys that hinder the measurement performance with a pre-determined accuracy. This article presents the limitations in unmanned survey vehicle (USV) positioning in an area restricted by a high quay, and difficult observational conditions in the surrounding high harbour infrastructure. The positioning used a four-system receiver that determined position coordinates based on the signals from one, two, three and four satellite navigation systems. The number of available satellites was determined under conditions of the open upper hemisphere and the partially obscured hemisphere based on the surrounding geometry. The determined position coordinates were related to the position determined using robotic total station (RTS). An area was identified in which it becomes difficult or impossible to maintain the required positioning accuracy.

Section: Introductionmentioning

confidence: 99%

Limitations of Multi-GNSS Positioning of USV in Area with High Harbour Infrastructure

2023

Electronics

Self Cite

“…There are frequently ships anchored in a harbour basin, which prevent performing a survey of the whole basin. Mooring sites in marinas are made as Y-booms with a small distance between them [23][24][25]. The width of a mooring site is a manoeuverability-limiting factor.…”

Section: Introductionmentioning

confidence: 99%

Coastal Bathymetric Sounding in Very Shallow Water Using USV: Study of Public Beach in Gdynia, Poland

2023

Sensors

Self Cite

The bathymetric surveys executed with a use of small survey vessels in limited water areas, including offshore areas, require precise determination of the geospatial coordinates of the seabed which is a synthesis of, among others, determining the position coordinates and measuring the depth. Inclination of the seabed and the declining depth make manoeuvring of the sounding vessel, e.g., a hydrographic motorboat or Unmanned Survey Vehicle (USV), in shallow water impossible. Therefore, it is important to determine the minimal depth for the survey resulting from the draught of the sounding vessel and the limits of the sounding area. The boundaries also result from the dimensions of the sounding vessel, its manoeuvring parameters and local water level. Type of the echosounder used in the bathymetric survey is a decisive factor for the sounding profile planning and the distances between them and the survey vessel for the possibility performing the measurements in shallow water. Electronic Navigational Chart (ENC) was used to determine the water area’s boundaries, and the safety contours were determined on the basis of the built Digital Sea Bottom Model (DSBM). The safety contour, together with the vessel’s dimensions, its manoeuvring parameters and the hydrometeorological conditions, limit the offshore area in which the measurement can be performed. A method of determining boundaries of the survey performed by a USV equipped with SingleBeam EchoSounder (SBES) on survey lines perpendicular to the coastal line are presented in the paper in order to cover the water area with the highest amount of measurement data, with the USV’s navigational safety taken into consideration. The measurements executed on the municipal beach served verification of the DSBM.

“…The miniaturisation of vessels used in hydrography [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ], especially unmanned ones (USVs), and of measuring devices, in particular, the acoustic ones, including single beam echosounders (SBES) and multibeam echosounders (MBES), provides the possibility of their usage in limited water areas, especially in seaports where the ground conditions restrict the application of satellite devices and systems and where disturbance of the electromagnetic field caused by ferromagnetic objects is present. Compasses installed on USV, being an integral part of the autonomous measuring system, are not resistant to such disturbances, which results in no possibility for the sounding vessel to head along the sounding profiles in an automatic mode.…”

Section: Introductionmentioning

confidence: 99%

Determination of USV’s Direction Using Satellite and Fluxgate Compasses and GNSS-RTK

2022

Sensors

The measurement of a mobile object’s movement direction is performed by means of various analogue and digital devices, including both autonomous and non-autonomous ones. They represent different measuring qualities, dimensions, weights and tolerance to ambient disturbances. They allow measuring the course of heading and course over ground (COG) in sea navigation. They are used for the determination of motion vectors on the water’s surface and with respect to the sea bed, in integrated systems, DP and autopilots. Results of dynamic tests of three heading meters: electronic and satellite compasses, and Global Navigation Satellite Systems (GNSS) determining COG are presented in this paper. The measurements were conducted in good measuring conditions, in an open upper hemisphere for satellite receivers and at no or minimal disturbances of the magnetic field. Sensors were mounted on an unmanned survey vessel (USV) that was moving straight, performing quick turns and circulations. Each of them has some limitations with respect to its use in the water area in which a hydrographic sounding is to be performed; attention was paid to the possibility of using a given compass on board a small autonomous ship navigating automatically.