Reson SeaBat 7125 ROV, Operator'S Manual

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SYSTEM PERFORMANCE AND DATA TYPES
SeaBat 7125 ROV Operator‟s Manual
Page 102 May 30, 2011
Version 3
Table 3: SeaBat 7125 ROV System Performance
Parameters 400kHz 200kHz option
Sonar operating frequency 400kHz 200kHz
Across-track beam width
(nominal values
15
)
Transmit: >145°
Receive: 0.54° ±0.03°
(center)
Transmit: >142°
Receive: 1.1 ±0.05°
(center)
Along-track beam width
(nominal values
15
)
Transmit: 1.0° ±0.2°
Receive: 31° ±3.5°
Transmit: 2.2° ±0.5°
Receive: 28.5° ±3.8°
Across-track beams 256 or 512 256
Swath coverage
16
128°
or 140°
128°
or 140°
Range (typical) 0.5-300 meters 0.5-750 meters
Ping rate (range dependent) Up to 50 pings/s Up to 50 pings/s
Pulse length 33-300µs (CW) 33-300µs (CW)
Depth resolution 6mm 6mm
Depth rating 6000 meters 6000 meters
For available configurations, see
Appendix E Available SeaBat 7125 Configurations .
7.1 Data Types
7.1.1 Bathymetry Data
At 400kHz, the SeaBat 7125 ROV generates 256 (or 512
17
) equiangular or equidistant
soundings per ping. At 200kHz, the system generates 256 equiangular (or equidistant)
bathymetry soundings per ping. The system broadcasts from the processor to the data
acquisition software, where they are corrected for mechanical offsets, motion, heading,
refraction, tide or depth, and position. To perform these corrections, the appropriate
sensors must be interfaced to the data acquisition software (see
section 4.4 I/O Module
Configuration ).
Depending on the beam angle, bottom type, and signal characteristics, the bottom
detection method employed may be magnitude center-of-energy, phase slope zero-
crossing, or a blend of the two methods. The bottom detection method can vary from
ping to ping and beam to beam.
15
All beam width measurements are performed at -3dB, unsteered with a sound velocity of
1480m/s.
16
The swath coverage of 140° is available with the Efficiency feature package (see Table 22 ).
17
Available with the Efficiency feature package (see Table 22 ).