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   SeaSonde Remote Unit
Specifications & Configuration

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SeaSonde® Remote Unit System Specifications

Product Code: SSRS-100

SeaSonde Remote Unit Components
• 1 Transmit Antenna Assembly (SSTA) & 1 Receiver Antenna Assembly (SSRA) OR,
   1 Combined Transmit-Receive Antenna Assembly (SSTR) (avail. for frequencies 11.5 MHz and higher)
• 1 Transmit Cable & 1 Receive Antenna Cable Set OR,
   1 Combined Transmit-Receive Antenna Cable Set (avail. for frequencies 11.5 MHz and higher)
• 1 SeaSonde Receiver Chassis (SSRX)
• 1 SeaSonde Transmitter Chassis (SSTX)
• 1 Radial Site Data Acquisition System (SSDA 100)
• 1 Electronics Interconnector Cable Kit
• 1 Set Operator Instruction Manuals, PDF format
• One Year Manufacturer’s Warranty
   † Base components only: review Remote Unit
   Configuration Options inside this specification sheet.

Technical Specifications
Radiated Signal Specifications

Operators must adhere to local radiated signal regulations and receive proper authorizations prior to operation.
Output Radiated Power:
80 W peak, 40 W average

Operating Frequency Range:
   Electronics: 4.4 – 50 MHz
   Antennas: Select from one of either:
   4.4 - 6 MHz or
   11.5 - 14 MHz or
   24 - 27 MHz or
   40 - 45 MHz or
   custom: any other frequency between
   4.4 - 50 MHz
Modulation Format:
Pulsed Swept Frequency CW
Sweep Width: 12-300 kHz (typical)
Pulse Repetition Frequency:
514 - 8224 Hz
Sweep Repetition Frequency: 1-4 Hz
Total Radiated Signal Bandwidth: (at -20dB level) 65-200 kHz
Polarization: Vertical
System Power Requirement (transmitter, receiver & computer): 350 watts (24V DC ver.) or 500 watts (120-220 VAC)
SeaSonde TX & RX Antennae


SSDA 100  

SeaSonde RX Antenna SeaSonde TX Antenna

Transmitter Chassis: SSTX

Input RF Drive Level: 0 dBm
Output RF Power Level: 100 watts peak, 50 watts average
Power Requirements: 300 watts;
(select one when ordering):
   120 V AC, 50-60 Hz
   220 V AC, 50-60 Hz
   24 V DC
Design: (gated FET) modular; solid state
Operation: Class AB
Dimensions: (single chassis) 19” rack mountable, 3U tall;
13H x 49W x 53D (cm)
Weight: 15 kg
Temperature Range (ambient): 0° F (-18° C) to 90°F (32° C)
Maximum Humidity: 80% non-condensing
Receiver Chassis: SSRX

Maximum In-band Input Level: 0 dBm
Receiver Channel Impedance: 50 ohm
Sensitivity (noise level): -166 dBm in 1 Hz BW
Power Requirements: 100 watts;
(select one when ordering):
   120 V AC, 50-60 Hz
   220 V AC, 50-60 Hz
   24 V DC
Design: modular, solid state, three-channel
Operation: I/Q homodyne
Output: USB digital output; digital data at 4096 16-bit/second per channel
Dimensions: (single chassis) 19” rack mountable, 3U tall; 13H x 49W x 53D (cm)
Weight: 14 kg
[Optional “SHARE” GPS synchronization Feature:
GPS assisted stability: >.0001 ppm and 50 nsec on PPS ]
Temperature Range (ambient): 0° F (-18° C) to 90°F (32° C)
Maximum Humidity: 80% non-condensing
System Requirement: AC Power Conditioning via
Uninterruptable Power Supply (UPS).
Minimum recommended UPS capacity: 1500 VA (1050 Watt)

Requirement- Cabling Protection:
Ideally cables between antennas and electronics are fed through protective conduit (such as 3.5 cm diameter PVC pipe) and buried in trench. There are lower cost options available, but there will be greater risk to exposure and damage.

Transmit Cable
Type: Single Strand RG-8 Low loss Co-Ax, 75 m length

Receive Cable Set
Type: Quad strand RG-58 Low loss Co-Ax bundle, 100m length

Combined Transmit - Receive Cable Set

(for 11.5 MHz and higher frequency bands)

Type: 1 x RG-8 + 2 x RG-58 Low-loss Co-Ax bundle,
Length: 75m (optional custom lengths available)

Note: Antennas for operation at one frequency band and bandpass filters for operation at two frequency bands are included with SeaSonde remote unit purchase. Antennas and filters for operation at additional frequency bands can be purchased separately.

Requirement - Bases/Mountings for Antennas:
Antennas need to be mounted vertically secured to concrete concrete pad (~ 1m x 1m 1m) or lashed/guyed to fencing or other solid structure. Read SeaSonde Antenna Installation User's Guide for examples.
Receive Antenna Assembly
Consists of:
   mast, dome loopstick antenna unit &
   vertical element (set atop dome)
Durability: All-weather
Total antenna height:
   4.3 - 5.4 MHz: approx. 6.5 m
   11.5- 14 MHz: approx. 6.5 m
Design: passive vertical monopole,
two crossed loops into preamplifiers
Functionality: omnidirectional, adjustable
(in software) from 1-360 degrees

Transmit Antenna
Durability: All-weather
Total height:
   4.4- 5.3 MHz: approx. 8.6 m
   11.5-14 MHz: approx. 8.6 m
Transmitting Design:
    vertical monopole; omnidirectional

Combined Transmit - Receive Antenna Assembly

(for 11.5 MHz and higher frequency bands)

Consists of:
   mast, dome loopstick antenna unit &
   vertical element (set atop dome)
Durability: All-weather
Total antenna height:
   11.5- 14 MHz: approx. 8 m
   24-27 MHz: approx. 6.5 m
   40-45 MHz: approx. 5.5 m
Receiving Design:
   passive vertical monopole, two crossed loops into preamplifiers
omnidirectional, adjustable from 1-360 degrees
Transmitting Design: vertical monopole; omnidirection

Requirement – SeaSonde Antenna Placement
Clear Space Around RX and TX Antennas
Objects that interact with or alter the response of the transmit or receive antennas can affect bearing accuracy or create bearing gaps in coverage.
• Position SeaSonde transmit or receive antennas one horizontal RADAR wavelength or greater away from tall (one quarter of the RADAR wavelength or taller) objects or obstructions (see chart below). Tree trimming/removal, or relocation of other man made objects may be necessary.
• There should be no obstructions between the receive antenna and the seaward side that may block energy in direction of ocean.
• Position receive antenna one horizontal RADAR wavelength or greater away from a cliff or building edge (see chart above).

Requirement- Transmit Antenna Ground Plane Dimensions
The Long-Range (4.3-5.4 MHz) SeaSonde Transmit antenna requires a ground plane. If the antenna is attached to a metal structure, such as on an oil platform or metal fence, then that object will act as the grounding device. If it is to be installed on a beach, for example, then grounding elements will need to fan out from the base of the antenna towards sea. A minimum of 9 elements need to be placed in a 180 semi-circle on the seaward side of the antenna. Each element is a metal wire encased in plastic (~1/8” diam.), whose length is about 7-8 m. These elements can be buried under sand or laid above ground.
Distance (Horizontal) from Water to Antennas
Antennas should be positioned close to the water to prevent propagation loss of energy traveling over ground. Maximum recommended distance from transmit or receive antenna to water is four RADAR wavelengths (see above chart).

SSDA 100 Consists of:
   Computer: select one of either mini-style or laptop computer
   Monitor: color TFT
   keyboard and mouse: USB, extended
   Radial Suite Software License (individual site use)

Temperature Range: 0° F (-18° C) to 90°F (32° C) for mini-style computer
Maximum Humidity: 80% non-condensing
Compatible Communications: 10/100/1000 Base-T Ethernet (RJ-45 connector) transfer of current, wave and diagnostic data products supported by software
Communication Link Requirement
   • A reliable data communications link is required for:
   • Real-time data transmission,
   • Real-time system monitoring,
   • Proper system maintenance and customer support,
   • Remote software updates.
   • Minimum data bandwidth (upload and download each): 256 kbit/s.
Radial Suite Software Data Products

Radial Surface Current Velocity Maps
Radial Map Display: color monitor screen, archived ASCII vector files-- formatted to CODAR's LLUV columnar table format (MatLab® loadable).
Spatial Range (typical): 20-220 km offshore; 20-220 km alongshore
Range Resolution: user selectable from 200 m - 12 km. Resolution is based on transmit signal sweepwidth.
Angular Resolution: 1-5 degree grid: user selectable.
Current Accuracy: Varies with environment. rms typical for normal environmental speed: < 7 cm/s of the total current velocity and 1-2 cm of the tidal component, direction < 10 degrees.

Doppler Cross Spectra
Binary files of HF sea echo spectra for three receive channels (two crossloops& vertical element). Raw and averaged are available for processing into radial vector maps.
Range Processed Spectra (Range Series)
Optional binary files of receiver range processing which can be processed into Doppler cross spectra.
Raw I & Q voltages (Time Series)
Optional binary files of receiver analog measurements which can be processed into range spectra and Doppler cross spectra.

Wave Field Parameters
Local on-shore wave conditions in ring centered 3km from coast around each radar. Measurement range cell user-selectable.
Significant Waveheight. typical accuracy: 7-15%
Dominant on-shore Direction. typical accuracy: 5-12 degrees
Dominant Wave Period. typical accuracy: 0.6 s
Waveheight Energy vs. Frequency: ~0.01 Hz spacing
Dominant Wave Direction vs. Frequency: ~0.01 Hz spacing
Spectral Wave Frequency Range: 0.05 Hz - 0.25 Hz (20 s to 4 s periods)
Minimum Detectable Significant Waveheight: 1 m
Data Temporal Interval: User selectable. Typical wave averaging performed over one hour
Wave History Displays: hourly waveheight vs. time. Hourly wave direction vs. time. Hourly wave period vs. time (Note: Wave information is limited by environmental conditions and operating frequency).

ASCII or image of diagnostic time series data for system hardware, software and data performance parameters. ASCII files are formatted to CODAR's columnar table format (MatLab® loadable).
SeaSonde Radial Software
   • Real-time autonomous operation
   • Real-time system monitoring, logging (via email)
      • Hardware
         • Temperatures
         • Voltages
         • Data Acquisition
         • Miscellaneous Hardware
      • Software
         • Applications/Tools running not)
         • Data collection & processing
         • Acquisition and archiving
• Configuration done via Graphical User
• Layered configurable properties for both and advanced functions
• Graphical or command line control and monitoring
• Visualization Software for all stages binary I & Q to vector maps) and diagnostics
• JPEG or PNG plot images for sharing or web publishing
• Data archiving utility
• External Antenna Response Calibration Implementation
• Multiple levels of configurable Quality
      • Signal-To-Noise Computation & Thresholding
      • Peak Identification & Characterization
      • Ship Echo Removal
      • Burst Interference Removal (Lightning Others)
      • Ionospheric Noise Removal
      • Outlier Detection & Removal

2009 SeaSonde Remote Unit Configuration Options

SSRS-100 specification, v4, rev 03/2010

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