Tuesday, September 17, 2013

Color Enhancing your Sonar Log

ciBioBase's Trip Replay feature that couples bottom depth, aquatic vegetation biovolume, and bottom hardness maps with your actual Sonar Log empowers you with a verification tool that ensures an accurate map in every system you map, every time.  The sonar log also provides users and our Quality Control team helpful information about signal quality and transducer placement that can help both parties diagnose issues.

A little known feature in ciBioBase allows users to reprocess their Lowrance HDS/Elite sonar log at different color and sensitivity settings (Figure 1).

Figure 1. Trip Reprocessing Tab that allows ciBioBase users to reprocess their trips with new edits.  Try reprocessing your sonar log at a higher color (e.g., 240) for "cooling" the colors in your sonar log in ciBioBase and to bring out subtle bottom features.
Sometimes, your Sonar Log may look a little too "hot" making it difficult to distinguish between plants and bottom (Figure 2).

Lowrance, ciBioBase, Sonar Log
Figure 2.  Sonar Log showing colors that may be "too hot" to distinguish between plants and bottom.
Try reprocessing the sonar log at a colorline of 240 (default is 220).  This will bring in "cooler" colors to the sonar log and may help you better distinguish subtle bottom features and gaps in plant beds (Figure 3).

Figure 3.  Sonar Log reprocessed with a colorline of 240.
Alternatively, Lowrance has a powerful free desktop software program called SonarViewer which allows you to replay your Sonar Log with options to dynamically control sensitivity, colorline, zoom, and range (Figure 4).
Figure 4.  SonarViewer is a free download from Lowrance and has a range of tools for enhancing the contrast of bottom features detected by your Lowrance HDS or Elite.
Use SonarViewer to review your files prior to upload to ciBioBase if you suspect possible signal quality issues or are testing different transducer setups for optimal signal quality.  Signal Quality should also be continually monitored by watching your SONAR page on your HDS or Elite while collecting data on the water.  A helpful rule of thumb is that a signal that is clear and crisp to your eyes is most likely clear and crisp to ciBioBase algorithms.