| Popis: |
In this paper, we proposed a new low cost technique of sea-level observation and monitoring inspired by the classical Tide Pole (Tide Staff). The results obtained by our proposed High Frequency Rotational Tide Gauge (RTGHF) are promising. They show that RTGHF is very adapted to an agitated environment and is able to measure high and low frequencies oscillations (waves/swells, infragravity waves, seiches, meteotsunamis, tsunamis, tides, sea-level change, etc.). Contrary to modern tide gauges, where a measure is given with intermediate methods (pressure, ultrasonic, radar, bubbler, laser, etc.), this proposed solution is based on direct reading of sea-level movement with a precision of 1 mm and sampling rate of more than two readings per second (2 Hz). RTGHF uses a rotational floated patented system (Hemdane in Algerian Patent. N° DZ Patent: 9539. Echelle de maree cylindrique codifiee/houlographe a lecture directe et automatique des oscillations marines de hautes frequences, [1]) (Algerian Patent) where levels coded in barcodes. It is important to emphasize the existence of systems using barcode technology for water level measurement. To the best of our knowledge, some patents describe solutions through barcodes for no or less agitated water environments and groundwater (still water) (CN 201628523 U. Intelligent Barcode ruler, [5], CN 202024806 U. Underground water level observation device, [6]). On the other hand, thanks to its innovative rotational system (Hemdane in Algerian Patent. N° DZ Patent: 9539. Echelle de maree cylindrique codifiee/houlographe a lecture directe et automatique des oscillations marines de hautes frequences, [1])—which is very adapted to wave induced orbital motions (alternating crest/through)—RTGHF adapts to high frequencies characterizing an oceanographic environment (strong and perpetual agitations induced especially by waves). Therefore, our proposed solution based on a rotational system that allows the detection of high frequencies and thus makes it very suitable for marine and coastal environments. In addition, RTGHF operates without stilling well, and all high frequency oscillations are easily detected. Moreover, its low cost can make this technique very accessible for generalization of sea level observation. Then, RTGHF could help to better understand and monitor sea-level movement and thereby reduce coastal risks. |
