Study On The Non-contact Technique For Measuring Tidal Level Based On CMOS Sensor

As the basic element of marine hydrology, tide level is the important target ofocean observing and forecasting record, which often used as reference information formarine technology research. The tide measurement methods are variedly for differentenvironment. Temporary short-term measurement is used for coast and reefs tides. Ahigh degree of automation, environmental adaptability, high accuracy, low cost,simple installation and commissioning measurement is required. In this paper anon-contact, electro-optical imaging detection technology based, embedded tidegauge image acquisition and processing system for tide level measurement wasdesigned. A tide gauge automatic interpretation algorithm based on image processingand projection analysis methods was proposed. The experiments show that when theimage distance varies from25m to100m, maximum interpretation accuracy5mm isobtained.The main contents include:1、Proposed the overall design of tide level measurement, Completed the designof system architecture. The program includes telephoto optical imaging system design,gauge size and pattern design, mechanical structure design.2、Completed the design of image acquisition and hardware control circuit.Designed and accomplished the embedded DSP-based system which includes CMOSimage acquisition unit, control unit, Flash data store and the liquid crystal display unit,according to the needs of the actual measurement.3、Completed the design of image acquisition and system control DSP-basedsoftware. Proposed gauge image interpretation algorithm based on Sobel edgeoperator and projection analysis, achieved monitor images and control interfacedisplay on LCD.4、 A lot of the water experiments were done, which verify the system’sfunctionality and performance indicators. Experiments achieved a good result.