Author: biobasemaps

BioBase is a cloud platform for the automated mapping of aquatic habitats (lakes, rivers, ponds, coasts). Standard algorithms process sonar datafiles (EcoSound Product). Depth and vegetation maps and data reports are rapidly created and stored in a private cloud account for analysis, and sharing. This blog highlights a range of internal and external research, frequently asked questions, feature descriptions and highlights, tips and tricks, and photo galleries.

The Wake Up Call to Action for Objective Lake Monitoring and Management

The unexpected consequences of fighting Eurasian Watermilfoil, preventing fish from successfully reproducing?  Response by Contour Innovations’ President Matt Johnson

Recently, freelance journalist and underwater photographer Eric Engbretson published an article entitled ‘The unexpected consequences of fighting Eurasian Watermilfoil, preventing fish from successfully reproducing?‘ on a news service blog sponsored by Fishiding.  The article’s focus was Lake Ellwood Wisconsin where Wisconsin DNR Fisheries Biologist Greg Matzke presented evidence of declining Largemouth bass, Northern pike, and bluegill populations and evidence of recurrent reproduction/recruitment failures of these species.  Much of what is presented can be found in a draft WI DNR Fisheries Report.  Matzke speculates that declines in populations of these vegetation-dependent species may be due to a loss of aquatic vegetation over the last 10 years by repeated whole lake treatments.  In the DNR Report Matzke presents spotty, often subjective estimates of aquatic plant abundance which makes it difficult to confidently associate aquatic plant declines due to treatments with declines in fish populations.

It’s often difficult to respond to topics like this because, as a non-biologist and an employee of private company that provides a product for this field, I’m always concerned that my comments would be misconstrued as commercial, driven by my interest to sell products or my failure to understand the biology behind the “whole picture.”  I approach this topic as an outsider that gets to observe the industry and sometimes provide a unique perspective without a specific interest or deep understanding of a particular biological issue.   It is this observation stance that allows me to recognize that this article is a wakeup call regardless of position.

Every opinion, no matter what side of a topic you land on, will go nowhere if we don’t have objective information to make an argument or defend a position.  This is something both government biologists/regulators and aquatic service providers should agree on here.  This report is an opportunity to finally connect all groups within the aquatics field to perform holistic investigations, recognize when there’s a lack of good data, and take steps to acquire critical data.  It’s an opportunity to have the discussion the aquatics field deserves.  Failing to at least put resources towards making the connection between data inadequacy and historical needs from this article is a failure in the structure of the aquatic industry and maybe even society.  Compliance is one thing while a constant quest towards better data-intensive monitoring and management is quite another.

Sometimes this lack of “good data” is a result of a failure of technology to provide the tools required to gather and analyze the information we need, and sometimes it’s for other reasons like budget, human resources, access, and priorities.  I struggle with the paradox that the some people who argue that we need to look at the data before we make decisions on Ellwood are some of the same people I’ve seen resist an objective method that can provide these results.  It doesn’t add up.  Without objective, repeatable aquatic plant assessment methods, the field never moves forward and everyone gets to pick a side and stay there. Consequently, circumstantial evidence and speculations are used to assign a cause and place blame.  This puts the accused on the defensive using lawyer tactics to avoid any accountability.  This gets us nowhere

A way forward . . .

Contour Innovations is already helping to facilitate collaboration between fish monitoring and invasive plant management with fantastic, even unexpected results.  All involved hope the data sharing model grows into the future of monitoring and management.  By using an objective, passively logged and repeatable system of plant abundance and characteristic monitoring, multiple interests are benefiting simultaneously.   Fisheries managers are using quantitative measures of aquatic plant habitats to formulate fisheries management goals, Invasive aquatic plant managers are using these same data sets to evaluate invasive nuisances and are taking measures to address the nuisance while not compromising fish habitat.  This is a different way of thinking proactively instead of reactively and we can’t miss opportunities to highlight the need.  We can claim that the technology is the future, but technology is merely a catalyst for the necessary paradigm shift.

Our position has remained consistent since the Company’s founding, but is more relevant now than ever: That is, prudent management and regulation of lake ecosystems requires that decisions be based on objective, quantitative information about the status and trajectory of the system(s) of interest.  Continued decisions in an information-poor or anecdotal-evidence environment risk situations and blame like those observed on Lake Ellwood.

We haven’t picked a side but the industry and field needs to embrace or seek a more standardized or objective way of measuring aquatic plant abundance data.  I’ve heard a lot of requests for automated speciation data but here we are wishing we had objective abundance data.  There are some “cool” parts of our systems but we started BioBase because it fills a need.  Subjective methods of plant monitoring are already outdated. This has never been more apparent.

Guest Blog: Using BioBase to determine sedimentation in the Central Arizona Project canal

by Scott Bryan

The Central Arizona Project (CAP) is a multipurpose water resource development and management project that provides irrigation, municipal and industrial water to much of Arizona.  The primary means of water conveyance is a 336-mile concrete-lined aqueduct that transports water from the Colorado River, on Arizona’s western border, across the State to Phoenix, and then southward to the aqueduct terminus near Tucson.  Each year, over 1.5 million acre-feet of water is delivered to our customers.

Since its completion in 1993, the aqueduct system has experienced increasingly severe sedimentation that creates problems within the pumping plants and in the aqueduct itself.  Because the sediments can decrease the flow capacity of the aqueduct, cause damage to pumps and internal systems, and restrict flow through critical filtration units, it is imperative that dredging operations occur periodically.

sedimentation, ciBioBase, water volume, depth, mapping, bathymetry
CAP forebay dredging in 2009

In the past, CAP performed intensive sonar based sediment studies to determine bathymetry and the amount of deposition in the forebay of each of the 13 pumping plants.  The surveys show when and where dredging operations should occur.  These surveys were contracted to outside companies with costs ranging from $40,000 to $120,000 annually.

In 2012, CAP began to use the sonar technology provided by BioBase to conduct its own bathymetry surveys in the pumping plant forebays.  Water depths are compared to historical baseline surveys and the volume of sediment in each forebay can easily be calculated.  Annual surveys allow us to compare sedimentation from year-to-year to determine loading rates and critical areas to target sediment removal.  Surveys of all 13 forebays can now be accomplished in three days rather than six months, and when compared to the expensive surveys from the past, are equally as accurate.

ciBioBase, bathymetry, water volume, depth, Lowrance, acoustics, mapping, sonar, sedimentation, dredging
Blue-scale bathymetric map of a CAP forebay.  The light blue contours show an area that is extremely shallow and is in need of sediment removal.

 

ciBioBase, sedimentation, Lowrance, downscan, sonar, mapping, bathymetry, depth, water volume
Example transect design and resultant bathymetric map coupled with the sonar log viewer.  Notice the detailed image of the forebay’s trash racks produced by Lowrance HDS DownScan
This new approach to bathymetric and sedimentation mapping saves time and money, allows us to evaluate results immediately, and makes dredging operations more efficient and timely.

Scott Bryan is the Senior Biologist for Central Arizona Project (CAP).  After receiving an M.S. in Fisheries Management at South Dakota State University, Scott worked as a research biologist for Arizona Game and Fish for 10 years, then specialized in lake and stream management for seven years at a private consulting firm in Albuquerque.  Scott’s current position at CAP includes a broad scope of work, including aquatic and terrestrial vegetation control, fisheries and wildlife management, invasive species research, and water quality monitoring.

Mapping Ponds with BioBase

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
Blue-scale bathymetric output created after 10-minutes of data processing time by BioBase servers after upload.  Map was produced by 1,000 passively acquired GPS and bottom points.  All map outputs (e.g., water volume or hardness – next picture) can be analyzed in your private BioBase online account or exported to GIS for more sophisticated data analyses and layering
Bottom hardness automated output automatically created along with bathymetric and aquatic vegetation layers  in BioBase.  Areas that are maroon represent hard areas that remained from the original construction of the pond.  Soft areas are represented by the lighter brown colors and represent sand deltas from parking lot runoff.  Hardness and bathymetric outputs can be used to assess whether storm water retention ponds require maintenance and where specifically to focus efforts

 

New BioBase Website and Mapping Dashboard

 

At BioBase, ease of use, organization, and user experience are top priorities.  We recognized that our old site wasn’t the best it could be, so over the last few months the website and dashboard have been rebuilt from scratch.  We’ve listened to all the questions our customers had and attempted to incorporate all of these into the new dashboard.   The result is a sleek, user friendly dashboard with a great user experience.  It’s fast and has the features to sort, organize, and use the important data you upload to your account for automated processing.  Now you can maximize your BioBase experience!

New features include:

  • Tagging – You are now able to add descriptive tags to each of your trips for better sorting
  • Improved Search Capabilities – search all categories generally by user last name, lakes, and even tags
  • Collapsing Trip Organization by Lake – Trips are categorized by lake in the dashboard and only loaded when you want them
  • Trip Track Quick View – Each trip in the dashboard provides a snapshot of where your track is on the water body for quickly identifying a survey area
  • Sort by Date – Trips can be filtered by date range so you’re only looking at the trips you want to see
  • Advanced Searching – This feature will allow you to sort by a specific category like file name, tags or water bodies
  • Support Tab – Many of the methods that we blog about are now available as PDFs and step-by-step Powerpoint documents in your account
  • Trip Support Request – Quick boxes within each trip allow you to communicate your questions directly to QC experts for a specific file or merge
  • Overall cleaner look for a better user experience!

This dashboard should be much easier to use and was designed so the things you are looking for are right where they should be.  We’re always interested in hearing from you so please log into your account and check out!  Let us know what you think and if you have questions about any of the new, powerful features

Detect Change in Your Lake Before it’s Too Late!

Citizens all over the globe love their lakes and go to great lengths and spend lots of money to protect and manage them.  In the US, the Environmental Protection Agency supports a multitude of State, Local, and citizen efforts to monitor water quality in lakes and has implemented a rigorous National Lakes Assessment.  Despite these efforts, lakes across the nation continue to be impacted from runoff pollution and invasive species proliferation under our noses. How does this happen?

Continue reading “Detect Change in Your Lake Before it’s Too Late!”

Guest Blog: BioBase and Arctic charr habitat in Windermere, U.K.

By Dr. Ian J. Winfield and Joey van Rijn

The Arctic charr (Salvelinus alpinus) is well appreciated as an important fisheries species in many northern areas of the world.  In addition, it is equally important to evolutionary biologists because of this species’ frequent development of ‘morphs’ or ‘types’ and their bearing on our understanding of mechanisms of speciation (Figure 1).  In the U.K., this fascinating fish is also recognised as having great nature conservation value.

Figure 1.  A female (top) and male (bottom) Arctic charr from Windermere, U.K.  Photo courtesy of the Center for Ecology and Hydrology)

Windermere is England’s largest lake and has been at the forefront of several areas of Arctic charr research for many decades, with the notable exception of studies of their spawning grounds (Figure 2).  Despite their long appreciated significance for the coexistence of autumn- and spring-spawning Arctic charr types, local spawning grounds have not been studied in any detail since their original brief description in the 1960s.  At that time, laborious and spatially-limited direct observations by divers showed that spawning requires the availability of gravel or other hard bottom habitat.  New information on these critical areas is needed by ecologists and evolutionary biologists and, more urgently, by fisheries and conservation organisations responsible for the management of Windermere.

Figure 2.  Breathtaking view of Windermere’s north basin; home to several spawning populations of Arctic charr.  Photo courtesy of Dr. Ian Winfield.

We are currently using the newly developed bottom hardness capability of ciBioBase to survey and characterise the spawning grounds of Arctic charr in Windermere.  Limited underwater video is being used for ground-truthing, but the combination of a Lowrance™ HDS-5 sounder with ciBioBase is allowing us to investigate the known spawning grounds with unprecedented speed (Figure 3).  For the first time, we have been able to document in detail the bathymetry and bottom features of a long-monitored (for spawning fish) spawning ground just north of the island of North Thompson Holme in the lake’s north basin.  ciBioBase is also enabling us to examine other known spawning grounds in Windermere and to expand our coverage to other potential areas previously unstudied.

Figure 3. An example ciBioBase output of bottom composition on and around the Arctic charr spawning ground of North Thompson Holme in the north basin of Windermere

The rapidity of the field component of hydroacoustic surveys is well known.  ciBioBase now offers us a similarly fast method of hydroacoustic data analysis for key environmental characteristics in relation to the spawning of Arctic charr.  This new approach helps us to dramatically increase our return on investment and also allows us to review results within hours of coming off the water, leading in some cases to us adapting our field plans on the basis of initial results.

Dr. Ian J Winfield is a Freshwater Ecologist at the Centre for Ecology & Hydrology in Lancaster, U.K.  He has over 30 years of research experience in fish and fisheries ecology, hydroacoustics, and lake ecosystem assessment and management.  Dr. Winfield sits on several regional, national and international advisory boards and is the current President of the Fisheries Society of the British Isles (FSBI).

Joey van Rijn is an undergraduate student currently following a BSc. degree course in Applied Biology at the University of Applied sciences, HAS Den Bosch, in the Netherlands. He is experienced in ecological and particularly phenological research including work on temperature-induced differences between urban and rural areas in the timing of blossoming and leaf unfolding in shrubs.  He has also been involved with the development of fish ways for standing waters in the Netherlands. Joey is currently undertaking a research internship at the Centre for Ecology & Hydrology in Lancaster, U.K., where his research mainly focuses on using hydroacoustics to investigate Arctic charr spawning grounds in Windermere.

GPS Accuracy Test of Lowrance HDS


At BioBase we put Lowrance HDS to the test for GPS precision and accuracy.  We know the importance of accurate maps but also recognize that “consumer-off-the-shelf” doesn’t mean it won’t provide the type of accuracy needed for accurate acoustic mapping.  The question lies more in how precisely accurate we can map aquatic environments with a “survey-grade” versus consumer GPS.  There are a lot of considerations when mapping from the surface of a water body.  Not only the accuracy of the GPS signal itself but the movement of a survey vessel on a liquid surface, wind, number of points surveyed, survey design, depth, acoustic cone degree, etc.  The list goes on because plants grow, you’re usually in a boat and water moves.  But, we can still investigate the precision of the WAAS corrected GPS from Lowrance HDS.  We were happy with our test results . . . but not surprised!

Units Tested:
  • Trimble GeoXH 6000 Series (post processing DGPS correction to 12” accuracy and precision)
  • Lowrance HDS-5 (WAAS-Correction Enabled)
  • Lowrance HDS-7 Gen2Touch (WAAS-Correction Enabled)

 

Methods:
  • Two individuals recording tracks while walking in same footprints, units held at chest level
  • One individual recorded a track with the Trimble Unit while the other held the HDS
  • Process repeated with the Trimble and HDS7 Touch
  • Data collected in a 2-acre soccer field in Minneapolis surrounded by trees
  • GPS Track lines from both units were uploaded to ArcGIS and converted to points
  • Point layers from both units were spatially joined and distance from each HDS track point to the nearest Trimble GPS track point was calculated
  • Conditions: Clear skies and HDOP (Horizontal Dilution of Precision) was less than 3
  • Testing Completed March 14, 2013

 

One glaring item that can be pulled from the chart above is the accuracy of the Trimble unit before DGPS correction.  Published accuracy is much different than actual accuracy.  You can see from the numbers above that the DGPS correction didn’t adjust the Trimble track by much. When compared against the static HDS output, the comparison hardly changes (from an average difference of .71m between the HDS7 Touch and Trimble™ DGPS before correction to .69m after correction and .45m to .83 respectively for the HDS5).  Even after DGPS correction, both HDS units performed extremely well with significantly less than 1m average difference between tracks (.69m for HDS7 Touch and .83 for the HDS5).
At Contour Innovations we’re focused on best and uniform geostatistical models, acoustic processing, number of data points, and other key standard operating/data collection procedures to create good maps.  The average difference shown in the chart above could even be significantly less than the size of your acoustic cone (depending on cone angle and depth).  Spacing of your sample points is also very important.  The Lowrance HDS system records up to 20 pings per second.  The precision and accuracy of a map created from such voluminous data sets is unmatched.  When analyzing this much data during your survey the geostatistical model and spatial references are substantially improved.

 

Geo-statistical algorithms:  No acoustic map is made up of a complete data set.  Data sampling points with less that 100% coverage still require a statistical model of extrapolation or interpolating of neighborhood points.  All aquatic maps are created with some level of geo-statistical model like kriging.  Ensuring accuracy of actual points will help decrease error coefficients of estimated data but more important is the type of geo-statistical model and spacing between data sampling sights.  There is a positive correlation of error coefficient and transect spacing.  We recommend transect spacing of less than 50m and even higher resolution and lower spacing depending on mapping objectives.

 

Geostatistics is a branch of statisticsfocusing on spatial datasets originally developed to predict probability distributions.  A number of simpler interpolation methods/algorithms, such as inverse distance weighting, bilinear interpolation and nearest-neighbor interpolation, were already well known before geostatistics, but it goes beyond the interpolation problem.  Kriging, the model we use, is a group of geostatistical techniques used to interpolate the value at an unobserved location from observations of its value at nearby locations.  This means that as you collect data along a transect, those data can be used to predict unobserved data between points to a statistically significant probability.  A good geostatistical model and the number of sample point are key to a complete and accuracy map!
A couple things to consider that could influence the accuracy and precision of your maps:
  • Pitch, Roll and Yaw – Wave action or other movements of the boat as you take a physical samples
  • Tree Cover – which isn’t as common when mapping open water like lakes
  • Relation of GPS antennae to transducer – Even with 12 inch DGPS accuracy, if you’re standing 3 feet from your transducer your data points will be off.  If you take a core sample and enter the results into a GPS device, your boat could easily have drifted a lot more than your potential error.   With Lowrance HDS we provide an external antennae that can be mounted directly above your transducer so your data collection is happening at the point spot of your GPS signal.
  • Overall Survey Design – The spacing of your transects is key as it relates to the ability to confidently make predictions in unsampled locations with your geo-statistical model. 
  • Speed of Travel – When looking at a wide range of data collection techniques and methods, speed is always the biggest consideration for accuracy and coverage.

 

“Published Accuracy” is much different than actual accuracy.  A lot of this is a guarantee from the manufacturer to be less than a certain error threshold at least 60% of the time and is not a minimum.
Because of this, there’s an opportunity to use scare tactics to discount the power of an off-the-shelf acoustic unit or GPS.  But, as we’ve described here, there’s a lot that goes into making a map!
We were very impressed with the performance of the WAAS corrected Lowrance™ HDS when compared against a system like the differentially corrected Trimble™ unit.  Though, we can’t say we’re surprised!
For more information on getting the best and most accuracy maps please contact one of our fisheries biologists and GIS experts.
Lowrance™ and Trimble™ are registered trademarks of Navico, Inc. and Trimble Navigation Limited respectively.  Neither Company contributed, authorized, or requested this testing.       

Legacy applications of commercial sonar

At Contour Innovations we stand on the shoulders of giants who proved commercial depthfinders are precise scientific instruments for the measurement of aquatic plant abundance and distribution in lakes.   As early as 1980, researchers saw the potential for fathometers/chart recorders/depth finders/sonar/echosounders – whatever you want to call them – to substantially reduce time, effort, and cost in assessing aquatic plant communities in lakes (Maceina and Shireman 1980).

The commercial sounders of the 1980’s had only a fraction of the power and resolution of what Lowrance manufactures today (not to mention integration with GPS) and investigators still boasted of the quality and cost-effectiveness of the data acquired.  Here are some excerpts:

Maceina and Shireman (1980): “The principle advantage of utilizing a recording fathometer for vegetation surveys is that savings in time and manpower can be accomplished.  In Lake Baldwin, 14 transects covering a total distance of 11.3 km were completed in three hours.” p 38.

Duarte (1987): “Direct harvesting is an expensive and time-consuming procedure (see Downing and Anderson 1985).  Two SCUBA divers require 20 min on average to harvest the biomass of six replicate quadrats at a single depth.  In contrast, six replicate echosounder transects require only 8-35 min to obtain biomass estimates for all depths, with the actual time required dependent on the littoral slope and the depth to which the plants grow.  Additional advantages of the echosounder method are (1) a continuous record of the vegetation, rather than at discrete depths only, with the latter resulting in inaccuracies when the mean biomass values are estimated, (2) nondestructive sampling, which allows monitoring of the growth of stands over time and (3) simultaneous recording of other variables such as percent cover (Stant and Hanley 1985), volume occupied by the submerged vegetation, and littoral slope (Duarte and Kalff 1986), which influences macrophyte biomass.” p. 734

In fact, Duarte (1987) publishes biomass prediction equation from acoustic estimates of plant height (a ciBioBase output) for 22 aquatic plant species.

Thomas et al. (1990): “Fortunately, shallow range (0-7 m) chart recorders are standard on many low cost (less than $400) commercial echosounders, so the data acquisition equipment costs are relatively low with respect to fisheries acoustic assessments, which makes this procedure relatively nontechnical and very cost effective” p. 810

The concept of using commercial acoustics for mapping lake bottoms is established and proven.  Contour Innovations has refined, streamlined, and automated the methodology with ciBioBase and delivers an intuitive visualization of the complex underwater world we call littoral zones.

A Raytheon DE-719 “fathometer” relic when plant biovolume was measured on paper charts with the use of planimeters.  Photo from www.euronet.nl.
Paper chart from a Raytheon DE-719 displaying dense hydrilla canopies and bottom in a central Florida lake.  Reproduced from Maceina and Shireman 1980; J. Aquat. Plant Manage.

Classic Literature
Duarte, C.M. 1987. Use of echosounder tracings to estimate the aboveground biomass of submerged plants in lakes. Canadian Journal of Fisheries and Aquatic Sciences 44: 732-735

Maceina, M and Shireman, J. 1980. The use of a recording fathometer for determination of distribution and biomass of Hydrilla. Journal of Aquatic Plant Management 18:34-39.

Maceina, M.J., Shireman, J.V., K.A. Langland, and D.E. Canfield Jr. 1984. Prediction of submerged plant biomass by use of a recording fathometer.  Journal of Aquatic PlantManagement 22: 35-38.

Stent, C.J. and Hanley, S. 1985. A recording echosounder for assessing submerged aquatic plant populations in shallow lakes. Aquatic Botany 21: 377-394

Thomas, G.L., Thiesfeld, S.L., Bonar, S.A., Crittenden, R.N., and Pauley, G.B. 1990. Estimation of submergent plant bed biovolume using acoustic range information. Canadian Journal of Fisheries and Aquatic Sciences 47: 805-812.

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!

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