Bathymetry of the southern part of the Baltic Sea in the vicinity of the Coastal Research Station (CRS) in Lubiatowo - year 2017 and 2018

Date of the measuring works: November 07-08, 2017 and December 17-18, 2018
The coordinates of the vertices of the polygon: 54 ° 50'14 "N 17 ° 48'37" E, 54 ° 49'57 "N 17 ° 48'45" E, 54 ° 50'22 "N 17 ° 51'03 "E, and 54 ° 50'38" N 17 ° 50'54 "E.
Coordinate system: The Polish height coordinate system Kronsztad 86 (PL-KRON86-NH) and the horizontal coordinate system UTM 33 (PL-UTM-33).
Conditions during the measurements on 2017:
Wave direction: N-E
Wave height [m]: 0.2 – 0.4
Wind direction: N-W
Wind velocity [m/s]: 3 - 4
Additional information: a small swell wave from the east
Conditions during the measurements on 2018:
Wave direction: W
Wave height [m]: 0.2 – 0.4
Wind direction: N-W
Wind velocity [m/s]: 3 - 4
In 2017, measurements were carried out with a multibeam sonar MultibeamResonSeaBat 8101 at a frequency of 240 kHz. In 2018, the study was performed with a multibeam sonar MultibeamResonSeaBat 7125 at a frequency of 400 kHz. Both sonars were mounted centrally on the bow of the boat. 25 profile passes were made, each 2500 m long, every 20 m. Before measurements, the sonar was calibrated on the Margaret wreck. Prior to calibration and measurements, the sound velocity was measured in a water column at intervals of 0.5 m. RTK corrections were downloaded from Leica SmartNet, which resulted in a position accuracy of up to 2 - 5 cm. A positioning compensator IXBlueOctans 1000 was also used to support positioning.

测量工作日期：2017年11月7日至8日，以及2018年12月17日至18日。
多边形顶点坐标：54°50′14″N 17°48′37″E、54°49′57″N 17°48′45″E、54°50′22″N 17°51′03″E，以及54°50′38″N 17°50′54″E。
坐标系：采用波兰高程坐标系克朗斯塔特86（PL-KRON86-NH，Kronsztad 86）与平面坐标系UTM 33（PL-UTM-33）。
2017年测量期间的环境条件：
浪向：北东（N-E）
浪高（米）：0.2–0.4
风向：北西（N-W）
风速（米/秒）：3–4
附加信息：存在来自东侧的小型涌浪。
2018年测量期间的环境条件：
浪向：西（W）
浪高（米）：0.2–0.4
风向：北西（N-W）
风速（米/秒）：3–4
2017年的测量采用型号为MultibeamResonSeaBat 8101的多波束声呐，工作频率为240 kHz；2018年的测量则使用型号为MultibeamResonSeaBat 7125的多波束声呐，工作频率为400 kHz。两台声呐均安装于船艏中央位置。本次测量共完成25条测线，单条测线长度为2500米，测线间距为20米。
测量前，声呐已在玛格丽特沉船（Margaret wreck）处完成校准。在校准与正式测量作业开始前，以0.5米的间隔对水柱中的声速进行了测定。RTK（Real-Time Kinematic）校正数据从Leica SmartNet平台获取，由此可实现最高2至5厘米的定位精度。同时还配备了IXBlueOctans 1000型定位补偿仪以辅助定位。