Modernisation of the Calais tide gauge within the RONIM network
From 19 to 23 October 2009, two electronics technicians from the Naval Oceanography and Hydrography department (SHOM) went to Calaisin order to replace the equipment installed in June 2003. The site has been instrumented with a digital tide gauge since October 1998.
Following numerous problems due to the portof Calaissilting up that resulted in a loss of data (or uncertainty over the data), a new type of radar sensor (Khrone Optiwave) has been installed. The latter, fitted in the open air at the end of a bracket (see image opposite on the left), has thereby overcome the problems of the float well silting up, and the non-linear filtering errors that may occur between the inside and outside of a float well (see, for example, Annex C of the book "La Marée" by B.Simon, published by the Institut Océanographique [Oceanography Institute] in 2007).
In addition, a GPRS internet link can now also transmit the data in real time. The latter may be viewed on the Internet site "Sea level station monitoring facility" of the Intergovernmental Oceanographic Commission (IOC). (http://www.ioc-sealevelmonitoring.org/).