Accuracy Expectations

How accurate can you expect your ROVL to be?

Many factors affect the accuracy of an ROVL system. In this section, we show some real data and discuss the factors in play in this test.

For this test, we took an ROVL system out on an ice-covered freshwater lake. By using an ice-covered lake, we were able to ensure the system elements were not moving around due to currents and wind. We used a Mk III system but the results for a Mk II system would be very similar.

We cut a hole in the ice for the transceiver in a place where the water was about 8 meters deep, and lowered the transceiver down about 3 meters. We then cut holes for the transponder at distances of about 110 meters, 200 meters, and 295 meters. The water depth increased slowly from the 8 meters at the transceiver to about 15 meters at the 295-meter distance. The bottom undulates along the path and there are vegetation patches to the side.

The transponder was lowered through the hole in the ice slowly to a depth of about 10 meters (with data being accumulated during the drop).

We used an inexpensive topside GPS at the transceiver location, placed on the ice and not moved during the test.

This test setup is not an ideal environment for sonar, for many of the reasons described earlier in this section. It does illustrate the accuracy expectations for real-world systems.

The image below is a snip of the test displayed on CeruleanMap. In the following pages we will look in more detail at each of the areas.

Overall Test Results