influence of antenna pattern distortions on surface current data collected by a
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
Influence of Antenna Pattern Distortions Influence of Antenna Pattern Distortions on Surface Current Data collected by a on Surface Current Data collected by a
CODAR HF-Radar SystemCODAR HF-Radar System
Josh T. KohutJosh T. KohutScott M. GlennScott M. Glenn
Donald E. BarrickDonald E. Barrick
Radial Velocity MapRadial Velocity Map
A
Brigantine Site
Moored ADCP
25 km
25 cm/s
Brant Beach Site
Radial Velocity MapRadial Velocity Map
A
Brigantine Site
Moored ADCP
25 km
25 cm/s
Brant Beach Site
• Range• Bearing
Location
AntennaAntennaPatternsPatterns
Role of Antenna Patterns in SignalRole of Antenna Patterns in SignalDirection DeterminationDirection Determination
Role of Antenna Patterns in SignalRole of Antenna Patterns in SignalDirection DeterminationDirection Determination
Loop 1Loop 2Monopole
0 . 2 4 0 . 4 8 0 . 7 2 0 . 9 6 1 . 2
6 0
2 4 0
3 0
2 1 0
0
1 8 0
3 3 0
1 5 0
3 0 0
1 2 0
2 7 0 9 0
N o r t h - S i t e A n t e n n a P a t t e r n s w i t h 8 - f o o t R a d i a l G r o u n d E l e m e n t s :S o l i d l i n e s - - m e a s u r e d p a t t e r n s ; d a s h e d l i n e s - - i d e a l p a t t e r n s N o r t h - S i t e A n t e n n a P a t t e r n s w i t h 4 - f o o t R a d i a l G r o u n d E l e m e n t s :S o l i d l i n e s - - m e a s u r e d p a t t e r n s ; d a s h e d l i n e s - - i d e a l p a t t e r n s
0 . 2 6 3 8 0 . 5 2 7 6 0 . 7 9 1 3 9
6 0
2 4 0
3 0
2 1 0
0
1 8 0
3 3 0
1 5 0
3 0 0
1 2 0
2 7 0 9 0
Measured vs. Ideal Antenna PatternsMeasured vs. Ideal Antenna Patterns
Calibration Runs
RunNumber
GroundPlane
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
RunNumber
GroundPlane
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
Measured Brant Beach Antenna PatternsMeasured Brant Beach Antenna Patterns
8 ft Ground Plane 4 ft Ground Plane
Loop 1Loop 2
Measured Brant Beach Antenna PatternsMeasured Brant Beach Antenna Patterns
8 ft Ground Plane 4 ft Ground Plane
Loop 1Loop 2
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)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
Calibration Runs
RunNumber
GroundPlane
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
Measured Antenna Patterns (4 ft)Measured Antenna Patterns (4 ft)
Brant Beach, NJ
Loop 1Loop 2
Brigantine, NJ
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)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
Calibration Runs
RunNumber
GroundPlane
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
Measured Antenna B PatternsMeasured Antenna B Patterns
Brant Beach, NJ
Loop 1Loop 2
Brigantine, NJ
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)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
Measured Antenna Patterns (4 ft)Measured Antenna Patterns (4 ft)
Antenna A
Loop 1Loop 2
Antenna B
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)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
Measured Antenna Patterns (4 ft)Measured Antenna Patterns (4 ft)
Antenna A
Loop 1Loop 2
Antenna B
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)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
ADCP ADCP ComparisonsComparisons
Radial Velocity MapRadial Velocity Map
A
Brigantine Site
Moored ADCP
25 km
25 cm/s
Brant Beach Site
Measured Site 1 Antenna PatternMeasured Site 1 Antenna Pattern
8 ft Ground Plane 4 ft Ground Plane
Loop 1Loop 2
GroundPlane
Remote SiteRMS(cm/s)
R2
(%)
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
Ideal Patterns Measured Patterns
ADCP and CODAR Radial Velocity ComparisonsADCP and CODAR Radial Velocity Comparisons
Brant Beach Antenna PatternsBrant Beach Antenna Patterns
8 ft Ground Plane 4 ft Ground Plane
Loop 1Loop 2
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)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
ADCP
ADCP
GroundPlane
Remote SiteRMS(cm/s)
R2
(%)
Ideal Patterns Measured Patterns
ADCP and CODAR Radial Velocity ComparisonsADCP and CODAR Radial Velocity Comparisons
8 ft Brigantine 8.2 81
8 ft Brigantine 7.2 90
4 ft Brigantine 8.7 86
4 ft Brigantine 8.9 88
Brigantine Antenna PatternsBrigantine Antenna Patterns
8 ft Ground Plane 4 ft Ground Plane
Loop 1Loop 2
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)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
ADCP
ADCP
MeasuredMeasuredvs.vs.
IdealIdeal
Radial Velocity MapRadial Velocity Map
A
Brigantine Site
Moored ADCP
25 km
25 cm/s
Brant Beach Site
• Range• Bearing
Location
CODAR and ADCP Radial Velocity Comparisons (8 ft)
Ideal PatternsMeasured Patterns
ADCP
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.
SummarySummary
Scott Glenn John Fracassi Sage Lichtenwalner Don Barrick Pete Lilliboe
AcknowledgementsAcknowledgements
Belinda Lipa Liz Creed Mike Crowley Capt. Ron Capt. Joe