We promote BioBase as an automated “easy-button” solution for creating aquatic maps, but unfortunately, mobile acoustic data collection is not something you can push a button and forget about and expect perfect results. Like using most other sophisticated instrumentation, users need to monitor that the instruments are performing as expected and sometimes make adjustments if they aren’t.
Maybe you’ve been hearing about this term in sonar circles called “Chirp” and noticing that most consumer sonar units now come with Chirp capability. Indeed, Chirp is a game changer for more precise definition of acoustic targets suspended from bottom (e.g., fish) and the technology is helping more anglers find fish in a wide range of aquatic environments (Figure 1). But what does Chirp mean for mapping the bottom of waterbodies? Does it provide any advantages or disadvantages over traditional 200 kHz frequency broadband sonar that is the foundation of Insight Genesis and BioBase
EcoSound mapping services? Here we take a brief look at Chirp, explain what it is, and present some findings from preliminary tests in a couple of different lake environments.
One of the best features of BioBase EcoSound and its sister technology for anglers, C-MAP Genesis, is the ability to aggregate partial maps created over time into a complete map later. The recent blog post on Ten Mile Lake in Minnesota, USA, details a notable example of the power of aggregation. However, changing water levels over the course of time can impact the accuracy of aggregated maps if recorded water depths are not offset against a standard benchmark water elevation.
As an addendum to our blog series on rapid, portable applications we wanted to experiment with a “thru-hull” mount of the 83/200 khz Lowrance HDS transducer on a kayak for mapping storm water retention ponds in an urban area of Minnesota (City of Maple Grove). Electrician putty (sold as “Duct Seal”) available for a few dollars at the neighborhood hardware store worked as a perfect medium for this application. Follow the series of pictures and captions to see how this worked!
|Electrician putty or “Duct Seal” available at most hardware stores can be used for shoot “thru-hull’ applications on kayaks or canoes|
|Figure 2. A 83/200 Lowrance skimmer transducer secured to the hull of a polyethylene kayak by duct seal putty. Care should be taken to remove all air bubbles from the mold before pressing in the transducer|
|James Johnson from Freshwater Scientific Services LLC gets his Lowrance HDS-5 all set to log data.|
|Tracks showing a concentric circle approach toward mapping ponds smaller than 10 acres. This one is 3 acres located in an urban area of Minnesota near Minneapolis (Maple Grove). Data took 30-min to collect|