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Information Briefing Regarding

CO-OPS’

Microwave Water Level (MWWL) Activities

Manoj SamantOctober 24, 2012

MWWL Activities Briefing

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Agenda

CO-OPS MWWL Activities

- History

- Testing and Analysis

- Guidance

- Status

- Summary

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• Testing is done for four MWWL sensors at NSWC Carderock, MD

• Miros Sm-094, Design Analysis WaterLog® H-3611i, Ohmart/VEGA

VEGAPULS 62, and Sutron RLR-0002

• Additional field testing and comparison with NWLON data for 3 to 5 years

done at Duck, NC; Money Point, VA; and Fort Gratiot, MI;

• MWWL-Aquatrak® sensor data was in agreement

• Additional testing done on four sensors at Duck Pier for 3 years

• Impact of large surface gravity waves - with significant wave heights

(amplitudes) of 1 meter and larger, and periods of 10 seconds and longer,

and strong long shore and cross shore currents noted.

• Observed large microwave-Aquatrak® differences with high energy events.

• Design Analysis WaterLog ® H-3611i sensor selected based upon high

reliability, low maintenance, and cost.

CO-OPS MWWL Activities - History

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• General guidance translated into specific guidance and related to NWLON

primary sensor standard deviations - 5 year average of monthly standard

deviations threshold selected (2 cm SD value).

• Requirements for MWWL Sensor Installation

• Stable vertical infrastructure,

• No sea surface ice,

• Protected areas (semi-enclosed, fetch limited coastal regions with a

small wave environment)

CO-OPS MWWL Activities –Testing, Analysis, and Guidance

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Sample NWLON Standard Deviation, Air and Water Temp

Monthly Average Standard Deviation of Aquatrak Sensor and

Surface Wave Indication

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Sample Graph Showing 5-Year Average of Monthly Standard

Deviations of NE NWLON Stations

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• Limited Acceptance of the Design Analysis WaterLog H-3611i Microwave

radar Water Level Sensor Test and Evaluation Report published by CO-OPS

in December 2010, which is available at

http://tidesandcurrents.noaa.gov/publications/Technical_Report_NOS_CO-OPS_061.pdf

• Report includes detailed comparison of MWWL vs NWLON reference

sensors at Port Townsend, WA; Money Point, VA, Fort Gratiot, MI, and Bay

Waveland, MS.

• Testing and analysis supports operational use of the WaterLog® Microwave

radar sensor in semi-enclosed, fetch limited coastal regions with a small

wave environment.

• Report also includes description of a 5 step lab verification test procedure

that is required prior to field deployment.

CO-OPS MWWL Activities – Limited Acceptance Report

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• CO-OPS formed a MWWL Transition to Operations (MWWL TOP)

committee at the end of FY 11. Currently there are 10 members and

meetings are held monthly.

• MWWL TOP Committee - Oversight of all of transition activities – planning,

testing, documentation, SOP, budget, schedule, operations, and

implementation plan. These are multi year efforts.

• MWWL TOP Committee will make a recommendation of which sites are

suitable for MWWL transition.

• Advantages of transitioning to MWWL sensor - no-diving, reduced AI time,

no-corrosion, removal of dissimilar metal effects, no reduction in accuracy

under limited acceptance criteria.

CO-OPS MWWL Activities – Transition to Operations

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• “Implementation of MWWL sensors into NWLON Operations – Requirements

for simultaneous comparisons between sensors”, S K Gill, 1/14/2011

published.

• “Implementation of MWWL sensors into NOAA Hydrographic Survey

Operations - Requirements for simultaneous comparisons between sensors”,

S K Gill 1/14/2011 published.

• These two documents provide the roadmap for how simultaneous

comparison will be done for control and subordinate stations.

• Guidelines for Implementation of Microwave Water Level Sensors for Short

Term Water Level Station Deployments is being drafted and reviewed.

CO-OPS MWWL Activities – Implementation Guidelines

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• Currently MWWL sensor installed at 11 stations – Duck, NC; Port Townsend,

WA; Fort Gratiot, MI: Bay Waveland, MS; East Fowl River, AL, West Fowl

River, AL; Dog River, AL, Bayou LaBatre, AL; Chicksaw Bogue, AL; Windmill

Point, Wachapreague, VA.

• Two hydro stations installed for Elizabeth River (Lafeyette River and Western

Branch) and data collected and data comparison performed.

• The comparison analysis between MWWL and the standard sensors (one

Acoustic and one pressure) showed mean differences of less than 0.02 m in

the 6-minute data with standard deviation of less than +/- 0.01 m.(#)

• The differences in monthly mean tabulation products showed less than 0.02

m differences. (#)

• The mean differences in the tabulated times of the high and low waters were

within 0.1 hour. (# “Microwave Data Processing for 9999972 Lafeyette

River and 9999939 Western Branch, Edgar Davis, May 10, 2011” ).

CO-OPS MWWL Activities – Recent Projects

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Typical MWWL Gauge Installation

Microwave Radar SensorDAA Waterlog H-3611i Sensor

• Non-contact, remote sensing capability requires significantly less hardware

• Easier and less costly to install than the acoustic or pressure sensors

• Reduced maintenance costs

• Level directly to zero of sensor

• Excellent performance in enclosed, low wave energy environments

Sensor and mount

One complete system

Primary and Redundant systems

Credit: Tom Landon and Robert Heitsenrether

Example - Mobile Bay Storm Surge Project

MW Radar Sensor as Primary and redundant mounted on bridge walls

MW Radar Sensor mounting plate w/ leveling target

Credit: Tom Landon and Robert Heitsenrether

Example - Mobile Bay Storm Surge Project

Two independent systems on each bridge; radar sensor used for both primary and backup

Dog River Bridge

East Fowl River Bridge

West Fowl River Bridge

Credit: Tom Landon and Robert Heitsenrether

Example - Mobile Bay Storm Surge Project

• Hybrid design incorporates aluminum frames built for the original designs

• MW radar primary sensor with pressure backup sensor of 25 feet.

Chickasaw Creek

Bayou La Batre Bridge

Installed Oct/Nov 2011

Credit: Tom Landon and Robert Heitsenrether

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• Based upon the limited acceptance report and the additional testing done,

CO-OPS has started implementation of MWWL sensors into operations for

both NWLON operations and NOS hydrographic and shoreline survey

operations.

• CO-OPS has developed a preliminary environmental assessment process

for determination where SD threshold conditions exist that would limit the

deployment of MWWL sensors for operational purposes.

• Based upon these criteria, CO-OPS will make a determination as to the

appropriateness of the use of MWWL sensor for each tide station location

required for upcoming hydrographic and shoreline surveys and CO-OPS will

provide this information to OCS and NGS during the survey planning stages.

CO-OPS MWWL Activities – Summary

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Thanks.

Questions?

(1) MWWL Gauge Costs – Short Term Station

(2) Sample Environmental Site Assessment – Watchapreague, VA

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Backup Slides

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MWWL Gauge Costs – Short Term Station

Ideas on Using Physical Characteristics to Derive Coastal Classification System

Parameters

Average Significant Wave HeightAverage Significant Wave PeriodStorm Frequency Occurrence 2D Fetch Distance

Mean Tidal RangeDiurnal Tidal Range1st Difference for 6 min water level

Air TemperatureSea Surface TemperatureSalinity

Air-Sea Temp Gradient

Lowest observed sea level

Average Vertical Density Gradient (dρ/dz)

Physical Characteristic CCS Parameter

1. Likelihood of increased MWWL Measurement Error

2. Max Range and Max Rate of Range Change

3. Likelihood of Ice Formation at Sea Surface

4. Likelihood of increased Aquatrak Measurement Error

6. Likelihood of increased Bubbler Measurement Error

5. Likelihood of well silting

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Scaled Maps with Distance Legend - Boundary Conditions and Fetch

CCS Parameter 1. Likelihood of increased MWWL Measurement Error

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Scaled Maps with Distance Legend - Boundary Conditions and Fetch

CCS Parameter 1. Likelihood of increased MWWL Measurement Error

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Scaled Maps with Distance Legend - Boundary Conditions and Fetch CCS Parameter 1. Likelihood of increased MWWL Measurement Error

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CCS Parameter 1. Likelihood of increased MWWL Measurement Error

Standard Deviation of 1 Hz Aquatrak Record – Surface Wave Indication

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Mean Tidal Range, Diurnal Tidal Range, and Water Level Rates of Change

CCS Parameter 2. Max Range and Max Rate of Range Change

Watchapreague Average TidesMean Range – 4.02 ft Diurnal Range – 4.51ft

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Standard Deviation of 1 Hz Aquatrak Record – Surface Wave Indication

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