TECHNICAL EQUIPMENT AND SOFTWARE OF EUROPEAN SEA LEVEL SERVICE SITE KLAIPEDA


1. Introduction

        European Sea Level Service (ESEAS) is an international collaboration of governmental and non-governmental organizations operating tide gauges along European coasts or providing sea-level related information originating from other sources such as satellite altimetry, GPS and absolute gravity measurements at tide gauges. ESEAS aims to provide quality-assured sea-level and sea-level related information for European waters to a broad range of scientific and non-scientific users. Tide gauge Klaipeda was certified as ESEAS Operational Site in 2003.

        In this paper the technical equipment including hardware and software of ESEAS station KLAIPEDA (KLPD) is presented. The tide gauge KLAIPEDA (previous name – Memel) was established in 1811 in the east part of the Baltic Sea, at the estuaries of Curonian Lagoon. Information about tide gauge in Memel could be found in reports of Prussia [1, 2]. Unfortunately data of sea level are available only from 1898. KLAIPEDA ID number at Permanent Service of Mean Sea Level (PSMSL) is 080161. Upgrading of the station is done according to the ESEAS-RI project (Contract No EVR1-CT-2002-40025)and PAPA project (Contract No EVR1-CT-2002-20012). KLPD site was equipped with digital float tide gauge, water temperature, air temperature, pressure and humidity sensors, wind sensor and GPS receiver with antenna. The four character ID KLPD and IERS DOMES number 10802M001 was assigned to the permanent GPS station KLAIPEDA. It is planned to provide near real time (hourly) data to corresponding data servers.

        The basic purpose of the Klaipeda tide gauge was to measure water level and water temperature. Now, after upgrading the station according to the ESEAS-RI project, the fields of observation are: water level and temperature, air meteorological parameters, wind speed and direction and earth crust deformations.



2. Site description

        The site is located in Klaipeda sea port (Lithuania). Geographic position and coordinates are given in Fig 1, the tide gauge house itself – in Fig 2 and view from the Baltic sea side – in Fig 3.


Fig 1. KLPD site location


Fig 2. Tide gauge house and tide gauge benchmark


Fig 3. View from the Baltic sea side (Klaipeda sea port gate)

        The tide gauge house, where the tide gauge and meteorological sensors are placed, is actually situated in a shipyard, therefore problems with communications and power supply have occurred. There was no possibility to put a new communications cable, as whole area is solid concrete, that’s why an old, not very reliable, telephone line was used as the best solution to this problem.

        During gales electricity is turned off in the whole of area for 24 hours or more. This is another factor, causing data loss. To prevent this, a powerful uninterruptible power supply system has to be built, as having a separate power cable is as impossible as having a separate communications cable.

        GPS receiver, its antenna and wind sensor are placed in port office, in this case no problems with power or communications have occurred.