Some of our customers have requested the ability to make their maps even more accurate by eliminating the distance between their transducer and the bottom. We listened!
Depth calculations (z) using hydro acoustics are calculated from the source (transducer) to the bottom. Because a depth finder transducer is typically mounted below the water surface, depth readings are always off by the distance between the bottom of the transducer and the surface of the water . . . not anymore! With the new z-offset feature, any user can now recalculate depths by entering this distance and reprocessing the trip. For example, if your transducer is 6 inches below the surface, all of your depth readings should have a half foot added to them. A 10 foot z should actually be 10.5” deep. With a .5” z-offset, all of your depths will be reprocessed for better accuracy. This is very important when calculating water volumes!
The z-offset feature can also be used for calculations to high water marks or draw downs. By using the z-offset for a 5 foot draw down scenario, our users can identify which bottom structures will be exposed as land (see below). In addition, lake and pond managers can determine total water volumes at a high water mark by measuring this distance. By simply offsetting all depth readings with a single z-coordinate offset, your trip will be reprocessed the way you want it. Water volumes, blue scale, and plant biovolume will all be recalculated in your account. Simple!
Below is an example of the z-offset in action for a simulated draw down. We took an accurate trip from Trout Lake in Wisconsin and offest the z-coordinate by 20 feet to simulate a 20 foot draw down. The new blue scale reflects the changes and displays the new land in green: