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Influence of Antenna Pattern Distortions on Surface Current Data collected by a CODAR HF-Radar System. Josh T. Kohut Scott M. Glenn Donald E. Barrick. Radial Velocity Map. Brant Beach Site. Brigantine Site. Moored ADCP. 25 km. A. 25 cm/s. Radial Velocity Map. Brant Beach Site.
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Influence of Antenna Pattern Distortions on Surface Current Data collected by a CODAR HF-Radar System Josh T. Kohut Scott M. Glenn Donald E. Barrick
Radial Velocity Map Brant Beach Site Brigantine Site Moored ADCP 25 km A 25 cm/s
Radial Velocity Map Brant Beach Site Brigantine Site Location Moored ADCP • Range • Bearing 25 km A 25 cm/s
Role of Antenna Patterns in Signal Direction Determination
Role of Antenna Patterns in Signal Direction Determination Loop 1 Loop 2 Monopole
Calibration Runs Ground Plane Run Number Environment Antenna Date 1 8ft Brigantine Brigantine 10/99 2 4ft Brigantine Brigantine 10/99 3 8ft Brant Beach Brant Beach 10/99 4 4ft Brant Beach Brant Beach 10/99 5 4ft Brant Beach Brant Beach 09/00 6 4ft Brant Beach Brigantine 09/00
Calibration Runs Ground Plane Run Number Environment Antenna Date 1 8ft Brigantine Brigantine 10/99 2 4ft Brigantine Brigantine 10/99 3 8ft Brant Beach Brant Beach 10/99 4 4ft Brant Beach Brant Beach 10/99 5 4ft Brant Beach Brant Beach 09/00 6 4ft Brant Beach Brigantine 09/00
4 ft Ground Plane Loop 1 Loop 2 Measured Brant Beach Antenna Patterns 8 ft Ground Plane
Loop 1 Loop 2 Measured Brant Beach Antenna Patterns 8 ft Ground Plane 4 ft Ground Plane 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 40 60 80 100 120 140 160 180 200 220 40 60 80 100 120 140 160 180 200 220 Angle (Degrees From True North)
Calibration Runs Ground Plane Run Number Environment Antenna Date 1 8ft Brigantine Brigantine 10/99 2 4ft Brigantine Brigantine 10/99 3 8ft Brant Beach Brant Beach 10/99 4 4ft Brant Beach Brant Beach 10/99 5 4ft Brant Beach Brant Beach 09/00 6 4ft Brant Beach Brigantine 09/00
Loop 1 Loop 2 Measured Antenna Patterns (4 ft) Brant Beach, NJ Brigantine, NJ 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 40 60 80 100 120 140 160 180 200 220 40 60 80 100 120 140 160 180 200 220 Angle (Degrees From True North)
Calibration Runs Ground Plane Run Number Environment Antenna Date 1 8ft Brigantine Brigantine 10/99 2 4ft Brigantine Brigantine 10/99 3 8ft Brant Beach Brant Beach 10/99 4 4ft Brant Beach Brant Beach 10/99 5 4ft Brant Beach Brant Beach 09/00 6 4ft Brant Beach Brigantine 09/00
Loop 1 Loop 2 Measured Antenna B Patterns Brigantine, NJ Brant Beach, NJ 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 40 60 80 100 120 140 160 180 200 220 40 60 80 100 120 140 160 180 200 220 Angle (Degrees From True North)
Loop 1 Loop 2 Measured Antenna Patterns (4 ft) Antenna A Antenna B 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 40 60 80 100 120 140 160 180 200 220 40 60 80 100 120 140 160 180 200 220 Angle (Degrees From True North)
Loop 1 Loop 2 Measured Antenna Patterns (4 ft) Antenna A Antenna B 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 40 60 80 100 120 140 160 180 200 220 40 60 80 100 120 140 160 180 200 220 Angle (Degrees From True North)
Radial Velocity Map Brant Beach Site Brigantine Site Moored ADCP 25 km A 25 cm/s
Loop 1 Loop 2 Measured Site 1 Antenna Pattern 8 ft Ground Plane 4 ft Ground Plane
RMS (cm/s) R2 (%) Ground Plane Remote Site 8 ft Brant Beach 12.2 60 8 ft Brant Beach 10.3 79 4 ft Brant Beach 10.1 79 4 ft Brant Beach 9.8 77 ADCP and CODAR Radial Velocity Comparisons Ideal Patterns Measured Patterns
Loop 1 Loop 2 Brant Beach Antenna Patterns 8 ft Ground Plane 4 ft Ground Plane 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 A D C P A D C P 40 60 80 100 120 140 160 180 200 220 40 60 80 100 120 140 160 180 200 220 Angle (Degrees From True North)
ADCP and CODAR Radial Velocity Comparisons RMS (cm/s) R2 (%) Ground Plane Remote Site 8 ft Brigantine 8.2 81 8 ft Brigantine 7.2 90 4 ft Brigantine 8.7 86 4 ft Brigantine 8.9 88 Ideal Patterns Measured Patterns
Loop 1 Loop 2 Brigantine Antenna Patterns 8 ft Ground Plane 4 ft Ground Plane 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 A D C P A D C P 40 60 80 100 120 140 160 180 200 220 40 60 80 100 120 140 160 180 200 220 Angle (Degrees From True North)
Brant Beach Site Brigantine Site Moored ADCP 25 km A 25 cm/s Radial Velocity Map Location • Range • Bearing
CODAR and ADCP Radial Velocity Comparisons (8 ft) Ideal Patterns Measured Patterns A D C P
Summary • Hardware setup and local environment play a significant role in pattern distortions • System accuracy improves with the measured patterns only when the measured patterns differ from the ideal. • Measured patterns improve system accuracy by placing the velocity vectors in the correct angular bin.
Acknowledgements • Scott Glenn • John Fracassi • Sage Lichtenwalner • Don Barrick • Pete Lilliboe • Belinda Lipa • Liz Creed • Mike Crowley • Capt. Ron • Capt. Joe