Evolution of a Comprehensive Testing Technique to Evaluate PIT-Tag Antenna

Performance

Matthew S Morris2, Robert J. Magie2, Richard D. Ledgerwood1, and Amy L. Cook2

2 1

Background

A towed application creates a barrier to evaluating antenna function, efficiency, and performance.

Early Antenna Testing

“Cube” “3 Pipe” “46-cm Cylindrical”

• Hand-held read range testing• Assessed system function• Did not have an adequate way to evaluate

efficiency or performance• Still working out logistics of towing an

antenna

400 kHz trawl antennas (1995-1999)

Area: 0.2 m2Area: 0.2 m2Area: 0.2 m2

Development of Performance Tests• Read range expansion in 2000• Increased antenna passage• Wanted to simulate fish moving through antenna• Needed convenience and frequency

“0.9-m Single” “0.9-m cylindrical” “1.1-m cylindrical”

134.2 kHz trawl antennas (2000-2008)

Area: 0.9 m2Area: 0.6 m2Area: 0.6 m2

Development of Performance Tests• Applied PIT tags to a vinyl tape measure• Random intervals (30, 60, 90, and 120 cm) and

two orientations (0 and 45 degrees)• Tape guided through center of antenna coils• Tape speed mimicked fish speed

0.9-m Cylindrical

Utilizing Performance Tests1. Test for differences between antennas

2. Test for temporal differences in the same antenna

Antenna Area (2006)

Total Tags* (N)

Mean Tag Reads (%)

0.6 m2 10,900 72.90.9 m2 15,100 63.9

1.1-m-diameter (0.9 m2)

Total Tags* (N)

Mean Tag Reads (%)

2006 15,100 63.92007 6,000 47.0

*ST Tags

Development of Efficiency Tests• Release of SST tags beginning in 2006• Developed “Matrix” antenna in 2007/08• Concern with antenna efficiency and collisions

because of fish density and antenna size• Redesigned test tape

“Matrix”

Area: 7.3 m2

Development of Efficiency Tests• Test Tape: 6 groups of 9 tags, 3 intervals and 2

orientations• Used to understand limits of antenna

performance• In-water and dry tests

Component 1

Component 2Component 1

Component 2

Utilizing Efficiency Tests

Matrix Antenna

30 60 900

20

40

60

80

100

45

0

o

o

Spacing Interval (cm)

Effici

ency

(%)

Utilizing Efficiency TestsMatrix Antenna (6- 0.7 x 3 m)

0.9-m Cylindrical Antenna

30 60 90Spacing Interval (cm)

45

0

o

o

02040

6080

1000

204060

80100

Effici

ency

(%)

Summary• Technique has evolved to evaluate antenna

function, efficiency, and performance in one test without releasing test fish

• Designed to be a rigorous test of antenna efficiency

• Validate antenna designs and temporal variation• Test tape layout can be tailored to fit a specific

application need • Valuable tool to fully understand an antenna’s

range of readability

Acknowledgments

Bruce JonassonDave MarvinMike MorrowHal Campbell

Sandy DowningEarl PrenticeEd Nunnallee

April CameronRussell PorterJohn Piccininni Scott Dunmire