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<br />on each reach of river using the same method as used on the IS-Mile reach (Sec. 2.1.2). <br /> <br />However, because flows were relatively low it was not possible to survey the margins of the <br /> <br />channel using GPS and sonar. As such, from the 27th through the 29th of July, the GPS was <br /> <br />used with a Psion data collector running Field Face software to survey in the waterline at the <br /> <br />DuffY Tunnel site. Waterline data was collected at the Sevens site in late August, but that data <br /> <br />was lost making it very difficult to model the site. <br /> <br />Data Reduction and Preparation <br /> <br />Each of the survey methodologies used required that data be collected over several <br /> <br />days, and in each survey methodology a large number of data were collected. Because of this, <br /> <br />quality control was a very important part of the survey process. Data from individual surveys <br /> <br />had to be joined together and an effort had to be made to determine when a sufficient amount <br /> <br />of data had been collected. The use ofGPS and sonar to collect data on the fly added <br /> <br />additional data issue since it was generally not possible to perform any quality control as the <br /> <br />data was being collected. <br /> <br />Using the total station, it was possible to only collect data where it would help define <br /> <br />the channel topography. As topographic data were collected over the summer, they were <br /> <br />input into the ArcView software package. Using ArcView it was possible to create a <br /> <br /> <br />Triangular Irregular Network (TIN) surface model of the channel. By mapping the <br /> <br /> <br />topographic points on the TIN it was possible to determine where additional survey points <br /> <br /> <br />were needed in order to accurately represent channel topography. <br /> <br />The use of GPS, sonar, and the COMLOG program resulted in a large amount of data <br /> <br />to be reduced during post-processing. As part of this data reduction, an Excel macro was <br /> <br />written to determine which points would be used as part of the final survey. First, the macro <br /> <br />20 <br /> <br />I <br />I <br />I <br />I <br />I <br />,I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />, <br />I <br />I <br />1 <br />1 <br />I <br />