Validation of a CODAR HF-Radar System

1
Optimized
Validation of a CODAR HF-Radar System at the
Longterm Ecosystem Observatory

Josh T. Kohut Scott M. Glenn John F.
Fracassi Robert J. Chant
Dr Jeff Paduan, Dr. Don Barrick, Pete Lilleboe
2
CODAR Total Vector Calculation
Kilometers

CODAR North
0 5 10
Little Egg Harbor
Great Bay
LEO-15
A T L A N T I C O C E A N
Atlantic City
3
CODAR Total Vector Calculation
Kilometers

0 5 10
Little Egg Harbor
Great Bay
LEO-15
A T L A N T I C O C E A N
CODAR South
Atlantic City
4
CODAR Total Vector Calculation
Kilometers

CODAR North
0 5 10
Little Egg Harbor
CODAR Central Site
Great Bay
?
LEO-15
A T L A N T I C O C E A N
CODAR South
Atlantic City
5
Radial Velocity Comparison with ADCP C
CODAR Site
Moored ADCP
25 km
A
25 cm/s
6
Raw Velocity Comparison with ADCP C
Northern Site
RMS 7.2 cm/s
ADCP CODAR
Time (year-day)
Southern Site
RMS 9.5 cm/s
Time (year-day)
7
Tidal Velocity Comparison with ADCP C
Northern Site
RMS 1.6 cm/s
ADCP CODAR
Time (year-day)
Southern Site
RMS 4.3 cm/s
Time (year-day)
8
Radial Velocity Comparison with ADCP A
CODAR Site
Moored ADCP
25 km
A
25 cm/s
9
Raw Velocity Comparison with ADCP A
Northern Site
RMS 19.5 cm/s
ADCP CODAR
A
200 201 202
203 204
205 206
Time (year-day)
Southern Site
RMS 19.6 cm/s
200 201 202
203 204
205 206
Time (year-day)
10
Role of Antenna Patterns in Signal Direction
Determination
11
Role of Antenna Patterns in Signal Direction
Determination
12
Measured vs. Ideal Antenna Patterns
13
Measured vs. Ideal Antenna Patterns
8 ft Antenna Elements
14
Measured vs. Ideal Antenna Patterns
4 ft Antenna Elements
15
Configuration Tests

• Ideal Antenna Pattern Assumption (8 foot
  elements)
• Ideal Antenna Pattern Assumption (4 foot
  elements)
• Smoothed Measured Antenna Patterns (4 foot
  elements)
• Measured Antenna Patterns (4 foot elements)
• Interpolation (Guassian Fit)

16
Northern Site Antenna Comparisons
8 ft Ideal Patterns
RMS 17.4 cm/s R2 0.14 NP 456
17
Northern Site Antenna Comparisons
4 ft Ideal Patterns
RMS 8.6 cm/s R2 0.78 NP 61
18
Northern Site Antenna Comparisons
4 ft Smooth Patterns
RMS 9.0 cm/s R2 0.80 NP 120
19
Northern Site Antenna Comparisons
4 ft Measured Patterns
RMS 8.3 cm/s R2 0.84 NP 114
20
Northern Site Radial Coverage
8 ft Ideal Antenna Patterns
Percent Coverage
21
Northern Site Radial Coverage
4 ft Ideal Patterns
Percent Coverage
22
Northern Site Radial Coverage
4 ft Measured Patterns
Percent Coverage
23
Summary

• Validation was angularly dependent prior to
  system tests
• Good comparisons within total vector coverage
  area
• Poor comparisons near the coast
• Pattern measurements proved valuable in system
  optimization
• Measured vs. smooth/measured patterns showed no
  real difference
• Interpolation software further optimized the
  system
• Number of data points
• Qualtiy of data points

24
Summary
25
Summary