RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water AVOIDING BIASED DATA DURING REAL TIME HADCP DATA COLLECTION

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Outline Available RDI HADCP Hardware Motivation for Test Test Setup Testing Results   Comparison VADCP vs. HADCP   HADCP Data When Vessel Present Conclusions

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Available RDI HADCP Hardware HADCP FamilyWork-HorseChannel Master MaterialAluminumPlastic Freq. (kHz) # Beams33322 Error VelocityYes No Ceramic Dia. (cm) Expected Range (m)* 13 x Depth9 x Depth18 x Depth13 x Depth9 x Depth Max. Range (m) * NOTE: Assumes 0 Degree Tilt

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Outline Available RDI HADCP Hardware Motivation for Test Test Setup Testing Results   Comparison VADCP vs. HADCP   HADCP Data When Vessel Present Conclusions

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Motivation for Test Large Ceramic (25 cm) 300kHz HADCP previously tested by NOAA. Result = 300 meters profiling range, no independent verification by VADCP. NOAA desired to test Small Ceramic (12.5 cm) 300kHz HADCP for operational use in deep channels. 2 nd test designed to include 600khz Vessel Mounted ADCP (VADCP) for independent verification

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Outline Available RDI HADCP Hardware Motivation for Test Test Setup Testing Results   Comparison VADCP vs. HADCP   HADCP Data When Vessel Present Conclusions

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing – Setup Site = Delaware River, Penns Landing, Philadelphia, PA WorkHorse HADCP   Frequency = 300kHz   Ceramic Size = 12.5 cm   Number of Beams = 3   Depth of Deployment ~2 meters   Tilt = +2 degrees   1 Ping Data stored

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing– Setup WorkHorse VADCP   Frequency = 600kHz   Ceramic Size = 7.5 cm   Number of Beams = 4   Bottom Tracking Capability

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results - X-Section Theoretical End of Profiling Range = 120 meters (accounting for +2 degree tilt)

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results – VADCP Holding Position NOTE: Distance to HADCP measured with laser range finder

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Outline Available RDI HADCP Hardware Motivation for Test Test Setup Testing Results   Comparison VADCP vs. HADCP   HADCP Data When Vessel Present Conclusions

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results Comparison of VADCP and HADCP Velocity Data

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Vertical ADCPHorizontal ADCP Range From Dock Depth Average Vel.Horizontal Average Vel. mmcm/secm % Error % % % % Testing Results HADCP vs. VADCP

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results Evaluation of HADCP Error Velocity + Correlation

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results Evaluation of HADCP Error Velocity + Echo Intensity

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Outline Available RDI HADCP Hardware Motivation for Test Test Setup Testing Results   Comparison VADCP vs. HADCP   HADCP Data When Vessel Present Conclusions

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results Evaluation of HADCP data Quality when Vessel Present

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results Evaluation of HADCP data Quality when Vessel Present

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results Evaluation of HADCP data Quality when Vessel Present

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results Evaluation of HADCP data Quality when Vessel Present +/- 40 cm/sec error excluded

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Testing Results Evaluation of HADCP data Quality when Vessel Present

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Outline Available RDI HADCP Hardware Motivation for Test Test Setup Testing Results   Comparison VADCP vs. HADCP   HADCP Data When Vessel Present Conclusions

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Conclusions (1) Use Guidelines for expected HADCP profiling range as a function of depth when planning data collection. BroadBand correlation most sensitive screen to identify “trends” and anomalies in HADCP data where the HADCP beams initially begin to interact with the bottom. Error Velocity is the most reliable screen for biases in HADCP that are caused by passing vessels.

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Conclusions (2) Error Velocity screening command should be set to <10x the expected single ping standard deviation to exclude biased data from passing vessels in the ensemble average. Minimum HADCP correlation threshold should be increased from the default of 64 counts to ~100 counts to assist with the screening of biased data from vessels Echo Intensity cannot be reliably used to screen out biases due to passing vessels or interaction with the bottom

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water HADCP Data QA Pulse Purpose = identify end of HADCP profiling range Implemented for testing of 150kHz HADCP ALLOWS ‘GREEN OR RED’ data QA CAPABILITY FOR NOAA

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water HADCP Data QA Pulse Presently not available in WorkHorse HADCP firmware Scheduled release in July 2006

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water 3 o Beam Width<0.5 o Beam Width

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Introducing The Workhorse 300kHz Long Range Horizontal ADCP! Blue Water 2002 Developments 10” (254mm)

RD Instruments Home of the ADCP Measuring Water in Motion and Motion in Water Plan View of 3-beam HADCP