A RAINFALL MEASUREMENT DEVICE USING UNDERWATER ACOUSTIC SIGNALS

MEASUREMENTS OF RAINFALL OVER LARGE BODIES OF WATER SUCH AS LARGE LAKES OR OCEANS ARE MADE INFREQUENTLY BECAUSE OF THE LACK OF AN ACCURATE MEASURING DEVICE. A LARGE PORTION OF THE EARTH'S PRECIPITATION FALLS OVER THE OCEANS; THEREFORE, IT IS ESSENTIAL FOR UNDERSTANDING GLOBAL CLIMATE TO HAVE ACCURATE MEASUREMENTS OF RAINFALL OVER LARGE WATER AREAS. A DEVICE WILL BE DEVELOPED TO MEASURE RAINFALL ACCURATELY BYUSING UNDERWATER ACOUSTIC SIGNALS. THE BASIC PRINCIPLE OF THIS DEVICE IS DIGITAL PROCESSING OF THE UNDERWATER ACOUSTICSIGNAL GENERATED BY RAINFALL TO DETERMINE ITS INTENSITY. THE PRINCIPLE HAS BEEN DERIVED THEORETICALLY AND DEMONSTRATED EXPERIMENTALLY. HOWEVER, THERE ARE IMPORTANT LIMITATIONS IN THE METHOD USED, AND IT IS PLANNED IN THIS PROJECT TO ESTABLISH MORE SOPHISTICATED SIGNAL-PROCESSING TECHNIQUES TO OVERCOME THESE LIMITATIONS. SPECIFICALLY, OUR GOAL IS TO IMPROVE SIGNIFICANTLY THE ACCURACY OF THE MEASUREMENTS: WHEREAS THE ACTUAL STATE OF THE ART YIELDS RAINFALL RATE ESTIMATES WITHIN A FACTOR OF 2 OF THE ACTUAL VALUE, THE GOAL OF PHASE I IS TO SHOW THE FEASIBILITY OF SIGNAL PROCESSING TECHNIQUES THAT WILL YIELD ESTIMATES WITH MEASUREMENT ERRORS NO GREATER THAN 20%. THE FEASIBILITY STUDY WILL INCLUDE THEORETICAL AND EXPERIMENTAL WORK. PHASE II WILL INCLUDE THE DEVELOPMENT OF A PROTOTYPE DEVICE AND ITS TESTING UNDER ACTUAL CONDITIONS, AND PHASE III WILL BE DEVOTED TO THE DEVELOPMENT OF A COMMERCIAL DEVICE THAT WILL ALLOW FOR EASY MEASUREMENTS OF RAINFALL OVER LARGE BODIES OF WATER.