Helpful Lowrance Hints: Depth Tracking

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.

Continue reading “Helpful Lowrance Hints: Depth Tracking”

Is StructureScan worth it? You be the judge

Debating whether it’s worth the upgrade to the new HDS7 Gen2 Touch StructureScan bundle?  Outside of the bigger screen and more intuitive touch technology than its older generation HDS5 sibling, the imagery produced by StructureScan should be reason enough!
Below are the same areas of a lake in Minnesota using the traditional 200 khz signal (top) and the 455 khz DownScan add-on (bottom).  A school of fish hovering over Eurasian watermilfoil plants is clearly resolved in the bottom image.  The wider cone angle of the traditional signal cannot adequately resolve these minute features.  BioBase leverages both signals to produce accurate map data sets and reproduce spatially explicit imagery for plant cover typing.  Contact us if you would like to know more about HDS features or are interested in purchasing a unit

Lowrance GPS Accuracy: Seeing is believing!

A quick post to demonstrate the precision of Lowrance’s internal WAAS corrected GPS antennae is in a variety of open water environments.  Docks? Boat lifts? Overhanging trees?  No problem.  WAAS correction in North America is explained here.  Have a look at a couple examples in ciBioBase:

GPS Track from a Lowrance HDS on Newport Bay, California overlain onto a bathymetry map created by automated processing of the Lowrance .sl2 log file by ciBioBase.  This trip was used for water volume calculations, bathymetry, and vegetation mapping

GPS tracks and ciBioBase derived bathymetry map in a 3-acre pond in a wooded valley in a metropolitan area of Minnesota, an example of retention pond volume monitoring.

GPS tracks and ciBioBase derived contour map of a 3-acre pond in Illinois for water
volume and aquatic vegetation analysis

GPS tracks around docks and boat lifts and ciBioBase derived contour map on Grand Lake O the Cherokees near Tulsa  Oklahoma.  The satellite even shows data collection in an area where a boat can be moored next to the dock.  That’s close!

Mapping is Easier with Passive Collection

I remember the days when you had to schedule an hour out of your field day to “set up” and “take down” your mapping set-up.  Wires, an echosounder, a transducer, a GPS, a PC to run everything all had to be set up and configured (Figure 1).  Most importantly, equipment had to be secured by creatively fashioned brackets, booms, and working platforms so you didn’t lose a $4,000 part.  Many horror stories over the years have been told by colleagues who forgot “Righty” was “Tighty” and as a result dropped an expensive piece of fish structure in the drink!

Figure 1.  Elaborate set up of wires, brackets, and working platforms needed to operate the  hydroacoustic systems of yesterday

Needless to say, life during this period was about dedication.  A dedicated survey boat.  Dedicated surveys.  Dedicated staff to run the equipment.  Dedicated staff to analyze the data.  Dedicated staff to oversee that “Righty” made “Tighty” (ok, maybe not that bad).  But still, the expense and logistics of such dedication kept hydroacoustic mapping out of the reach of most water and fisheries resource entities.

With advances in consumer sonar technology, GIS and cloud-computing, now anyone can create high quality bathymetry, vegetation, and bottom hardness maps and datasets with a $700 Lowrance Depth finder, a canoe, and access to the internet with a subscription to ciBioBase (Figure 2).

Figure 2. A 3.6-acre storm water retention pond mapped in 30-min (upload processing time = 10-min) using a canoe and a portable Lowrance HDS-5.  Red lines are the actual traveled track along which data were collected and uploaded to ciBioBase for the generation of the bathymetric map.

Who needs dedication anyway?

No needs for a dedicated boat. The unit can be made portable with no larger than a 12” by 8” footprint (Figure 3).  The transducer(s) and optional GPS can be mounted on a bracket available from Cabelas (Figure 4).  This set up can then be put on a range of vessels from a canoe to a large cabin cruiser.  It can be checked out and passed around by lake association subscribers taking turns mapping the lake on which they live if they don’t already have an HDS.

Figure 3.  Lowrance HDS units can be made portable a variety of different ways to fit your budget and  sampling needs.
Figure 4. Example portable mounts for transducers 
No needs for dedicated surveys. Whether you are a lake association member drinking cocktails (while staying under the legal limit of course) on pleasure cruise on your pontoon or a biologist going point-to-point sampling species of plants, passively recording sonar data requires no work outside of hitting “record,” inspecting the screen for signal quality (i.e., a clear picture), and uploading the data when you return from the field.  ciBioBase algorithms rigorously evaluate the quality of each signal and filter poor outputs (Figure 5).  Back in the day, the staff hydroacoustician had to do this.  Computers do this now.

Figure 5.  Example of automated data quality filtering by ciBioBase.  In the top example, bass tournament anglers were rapidly hopping from spot to spot.  Vegetation detection becomes unreliable at speeds greater than 12 mph.  Consequently, outputs are not generated at speeds that exceed this threshold.  In the bottom example, depths were shallower than 2.4 feet and thus not mapped because of detection errors in depths shallower than this threshold.  However, manual waypoints can be added in these locations within users’ ciBioBase account.

No need for dedicated staff trained in hydroacoustics and GIS.  Although ciBioBase offers much for the Hydroacoustic and GIS aficionados via data exporting and importing into their favorite data analysis software, training in hydroacoustics and GIS is not a prerequisite for creating good outputs and datasets.  Hydroacoustics and Geostatistics are not new or “soft” sciences that are so variable and complex that they can’t be automated (i.e., ecology).   The basic physics of sound traveling through water and reflecting off of various objects has been well understood for decades.  Concepts and applications of kriging (originally developed in the gold mining industry) are almost as old and well understood.  Accordingly, ciBioBase automates the interpretation of acoustic signals, creation of a GIS map layers, and standard summary reports.

Dedication in almost every aspect of life is an admirable virtue for which we all should strive.  However, when it comes to mapping lakes, rivers, or ponds, ciBioBase lowers the prestige of this virtue.  Indeed, there will always be a well-placed need for dedicated mapping.  However, we feel opportunities for understanding the dynamic nature of aquatic habitats will be missed if data are not logged while engaging in other activities on the water.  This is non-dedication at its finest!