KNOWLEDGE BASE

Technical resources to support shallow water hydrographic surveying

CEESCOPE™ and CEE ECHO™ Operation and Features

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What is an Echogram – Full Water Column Echo Envelope?

The CEESCOPE™ and CEE-ECHO™ output and record a high definition echogram, which is advantageous for determining accurate bathymetry. In addition to providing a complete record of the survey raw data, the echogram allows detailed post processing of recorded soundings to edit inaccurate or spurious depth signals, impossible to achieve with “black box” echo sounders.

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The Value of a Digital Echogram – Surveying over Sub Aquatic Vegetation

The CEESCOPE™ and CEE-ECHO™ output a high definition echogram, a view of the sonar echo envelope from the entire water column. That is not just a depth sounding value from each ping. The echogram output offers substantial benefits for surveys conducted in areas with sub-aquatic vegetation.

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The Value of a Digital Echogram – Surveying over a Soft Bottom

A dual frequency echo sounder is usually used for surveys where the bottom may be poorly defined, or when sediment resuspension is occurring, such as during dredging. In addition, collecting a digital echogram using the CEESCOPE™ or CEE ECHO™ helps provide a detailed view of the bottom and sub-bottom to allow proper identification of the hard and soft bottom surfaces.

Dual Frequency Echo Sounders for Sedimentation

A dual frequency echo sounder may indicate where sediment deposition is occurring and can show spatial distribution of areas of recent sedimentation. HYPACK® software has some excellent visualization tools to make use of this echo sounder output.

Using RAW GNSS Data Recorded on the CEESCOPE™ for Post Processed Precise Positioning in HYPACK®

The CEESCOPE® records raw GNSS data on its internal memory which can be extracted and used in post processing to recompute a precise positioning dataset after corrections using a reference station. The new position data may be inserted into HYPACK® in place of the original uncorrected data. This feature allows RTK-quality data to be collected in the absence of a local base station radio telemetry link or cell phone VRS network.

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Using the CEESCOPE™ and CEE ECHO™ in RTK Mode on a Local Grid

For land surveyors, the process used in hydrography to collect the coordinate position and elevation data underwater might be unfamiliar. However, using an RTK-enabled system it is easy to collect data that will fit seamlessly into separately collected land survey datasets using the same RTK GNSS receivers / base station.

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Using an External GNSS Receiver with the CEE ECHO™

The CEE ECHO™ is designed to take in NMEA0183 format position from a GNSS / GPS receiver and merge the position data with echo sounder data simultaneously being recorded. The combined data stream is output to an acquisition software package.

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Surveying Around Bridges Using the CEESCOPE™ and CEE ECHO™

The CEESCOPE™ and CEE ECHO™ record time-stamped data in the absence of a valid GNSS / GPS fix. This feature can be used in post processing to correct poor or unusable bathymetry data collected in areas where the sky view is restricted. Using interpolation, approximate positions can be assigned to the sounding depths collected during the GPS loss.

Single Beam Echo Sounder General Topics and Customer Projects

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Using the CEESCOPE™ and CEE ECHO™ with HYPACK® to Accurately Map Sub Aquatic Vegetation Extents

To determine the extent of sub aquatic vegetation coverage and the plant height, the echogram feature of advanced CEE echo sounders may be used in combination with HYPACK® editing and visualization tools to provide a simple and very effective habitat mapping option. An example Eelgrass survey in San Diego Bay, USA demonstrates the process.

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All Echo Sounders are not Created Equal – Ping Rates Matter

The echo sounder ping rate is a key feature that should be considered when selecting a single beam sonar system for bathymetry. Low ping rates (<5 Hz) cannot provide adequate coverage in challenging environments, and the advantages of high ping rates partly lie in data processing after the survey is completed.

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How the CEESCOPE™ was used to Find a Missing Structure

An unusual challenge was presented: use the dual frequency CEESCOPE™ to locate a 30m structure that had vanished – presumably sunk. The data processing in HYPACK® described in this article illustrates some general concepts relating to single beam echo sounder data and transducer properties.

CEE VIEWS – Why we do not make Echo Sounders with Paper Chart Recorders

Despite there occasionally still being a requirement for paper records supporting single beam hydrographic surveys, we choose not to offer any echo sounders that have this feature. Besides focusing more on portable units where paper is of no value, here are our thoughts on why we believe the paper chart to be entirely unnecessary.

CEE VIEWS – Why Single Beam Echo Sounders Continue to have a Place Alongside Multibeam

For many surveys, multibeam echo sounders have become the instrument of choice. However this is far from true for many types of hydrographic survey where a single beam echo sounder, possibly combined with a side scan sonar, offers the most attractive solution.

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CEE VIEWS – Industrial Water Hydrographic Surveying 

CEE HydroSystems’ equipment is used around the world for industrial water surveying – mine tailings ponds, process water reservoirs, paper mill effluent ponds, municipal waste water, oil field frac pits, and chemical plants. Some of the main topics involved in single beam hydrographic surveying in the industrial environment are discussed in this article. If you have survey projects in industrial water READ THIS ARTICLE before you get started.

Tailings Dam Bathymetry Paper TMW 2016

CUSTOMER PROJECT – Using a Dual Frequency CEE ECHO and a USV to Evaluate Mine Tailings Deposition

In addition to providing valuable water volume data for site water balance models and tailings storage facility (TSF) operations, using advanced echo sounder techniques may also provide insight into tailings deposition pattern and compaction processes. This paper as presented by Newfields LLC at the Tailings and Mine Waste 2016 conference in Keystone, CO, USA describes an unmanned survey vehicle approach to tailings dam bathymetry.

General Hydrographic Survey Procedures

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Basic Hydrographic Surveying Concepts

For surveyors not familiar with hydrographic processes and equipment, some of the commonly asked questions are answered.

RTK Tide Concepts for Precise Vertical Elevation Correction in HYPACK

Using GNSS height measurements has become the new standard for hydrographic surveying in order to correct elevation changes during the survey. The principle behind “RTK Tides” is simple however confusion may arise about exactly what is going on. This summary may help with some of the basic concepts behind RTK Tides.

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The Benefits of Time-Stamped Echo Sounder Data

Routing GNSS / GPS data directly to the echo sounder allows the precise time-tagging of the sounding position, offering reduced latency and a more resilient and exact survey dataset.