Acoustic Doppler Current Profiler

The current profiler used onboard is manufactured by:

Company	Model	Operating Frequency	Profiling Range
RD Instruments San Diego, CA	Ocean Surveyor	75 KHz	1000m

---

GENERAL DESCRIPTION

The RDI Acoustic Doppler Current Profiler (ADCP) employs the Doppler principle to measure speed and direction of currents in the water column below a moving vessel. By transmitting a succession of acoustic pulses, and segmenting the resulting backscatter echoes into many depth cells (bins) over a depth range of 8 to 1000 meters, computer analysis of the bins provides a detailed profile of current speed and direction throughout the water column. In waters where the bottom depth is within range, the ADCP bottom track feature measures earth referenced vessel speed. Combination of these measurements yields absolute (earth referenced) vertical current profiles from a moving vessel without inputs from other navigation systems. The PC Windows  based VmData Acquisition System (VmDAS) processes the ADCP data in real time together with vessel attitude and heading data to produce vector averaged profiles in earth referenced coordinates. Data is displayed in real time on a monitor or can be played back at a later time. 

 

The ADCP transmits acoustic pulses from a transducer assembly along four beams. The transducers receives backscattered echos from plankton and small particles riding the water currents. Using the Doppler effect and some basic trigonometry, the ADCP converts the backscattered sound into components of water current velocity. The ADCP measures the speed and direction of the current at multiple locations in the water column. The ADCP makes a profile of these measurements for up to 128 locations called depth cells or bins. Bins can be from 4 to 32 meters in length. For information on ADCP principles of operation and the Doppler effect, see RDI's Marine Measurements ADCP Primer..

Computer Systems

Servers

Three computers running Red Hat Linux operating system function as the ship's main servers. They are 'atlantic', 'pacific', and 'indian'. Indian is the only computer accessible to the crew and scientists. It functions as the ship's anonymous ftp site, domain name server, DHCP server, web server, print server and mail server. Atlantic is the main file server for all the ship's data acquisition systems, NTP (network time) server. Pacific is primarily used for data processing and to back up all the other servers.

Data Acquisition

Atlantic is used to collect and process Hydrosweep data and EM300 data. Several pc computers are used to collect ADCP, DAS/IMET, Navigation, CTD, Winch and Bathymetric data. Most of the data can be viewed on the ship's website, and DAS data may be viewed in near real time.

PCs and Macs

There are pc and Macintosh machines located int he Library, Science office and Main Lab that are universally available. The computer in the Computer lab are not available for general use because because they all perform specific functions. The Macintosh machines all run MAC OS/10 and the pc machines run Windows XP operating systems.

There is public disk space on Indian. Be advised that "public" means that anyone can view, modify or delete any file on that disk. If you have files that you want to protect, store them in your home directory on Indian.

Network Connections

The ship has a fiber optic Ethernet network with drops in all labs and staterooms. The Ethernet connections in the ships laboratories are all 10baseTX (10/100). Due to lack of fiber optic interface hardware, computer network connections in the staterooms are not supported.

Most computers can obtain an IP address from the DHCP server (Indian), however if a static IP address is needed ask the Marine Technician to assign one for your computer.

When the ship is at the University of Washington dock the network is connected to the outside internet via our gateway.

Some important information

Ship's web site: http://thompson.ocean.washington.edu

Main Server: indian
Server IP: 198.48.81.17
Subnet mask: 255.255.255.0

 

Domain: thompson.ocean.washington.edu
MS Workgroup: TGT
WINS Server: 198.48.81.17

 

Default Gateway: 198.48.81.100 (at UW Dock) 128.95.112.1

 

Name Server: 198.48.81.17
DNS Service Search order: 198.48.81.17

DAS/IMET System & File Format

The DAS system collects data at an operator selected interval; this is typically set at one sample (saved) per minute. The data collected are from the IMET sensors, SBE-21 Themosalinograph, Bathy-2000 and Winch systems. The data are time, date and position tagged. A new data file is started each GMT day at 00:00 and ends at 23:59 (depending on the data storage interval).

Near realtime DAS data can be displayed on any of the ships computers. Note that DAS data files may be found on the "indian" server in the directory /tgt-data/das.

The file configuration for DAS files TN133DAS.xxx follows:

Value Name	Value
1	Nav computer GMT date - (dd/mm/yyyy)
2	Nav computer GMT time - (hh:mm:ss)
3	Nav computer latitude - (+/-dd.dddddd)
4	Nav computer longitude - (+/-ddd.dddddd)
5	Gyro compass heading - (degrees true)
6	Nav computer COG - (degrees true)
7	Doppler speed log - (knots)
8	Nav computer SOG - (knots)
9	Thermosalinograph sea temperature - (degrees C)
10	Thermosalinograph sea conductivity - (Siemens/meter)
11	Thermosalinograph sea salinity - (PSU)
12	Thermosalinograph chlorophyll - (volts)
13	Thermosalinograph light transmission - (volts)
14	Water Depth - (meters)
15	IMET air temperature - (degrees C)
16	IMET relative humidity - (percent)
17	IMET barometric pressure - (millibars)
18	PAR - (microEinsteins per square meter per second)
19	IMET short wave radiation - (watts/square meter)
20	Wind speed true - (knots)
21	Wind direction true - (degrees)
22	Average true wind speed - (knots)
23	Average true wind direction - (degrees)
24	Sound Velocity - (meters/second)
25	Winch ID. number - (see note below)
26	Wire out - (meters)
27	Wire rate - (meters/minute)
28	Value 28 = Wire tension - (lbs.)

Winch ID
Hydro Winch 1 Trawl Winch Hydro Winch 2

---

Example DAS file from cruise TN133: filename TN133DAS.255

Kongsberg-Simrad EM300 Multibeam Echo Sounder

The EM300 is manufactured by Kongsberg-Simrad AS of Horten, Norway.

System Description

The Kongsberg Simrad EM 300 multibeam echo sounder is designed to do mapping from 10m depth to beyond the continental rises, including the shallower ocean basins. It operates down to approximately 5000 m depth with swath widths up to about 5000 m. Small transducers and compact electronics make the installation easy, and the system accuracy is generally well within the IHO standards.

 

The design of the EM 300 is based on more than 50 years of hydrographic experience with echo sounders, sonars and underwater positioning for civilian and military use. Kongsberg Simrad is today a part of the Kongsberg Group, a world wide organisation supplying advanced instrumentation for civilian, research and military maritime communities.

 

The Kongsberg Sirnrad EM 300 is a complete system. All necessary sensor interfaces, data displays for quality control and sensor calibration, seabed visualization, and data logging are a standard part of the system, as is integrated seabed acoustical imaging capability (sidescan).

---

Key Features

Operating frequency and coverage sector

Operating frequency and coverage sector The nominal sonar frequency is 30 kHz with an angular coverage sector of 135 beams per ping at 1 degree. The angular coverage sector and beam pointing angles may be set to vary automatically with depth according to achievable coverage. This maximizes the number of usable beams. The beam spacing is normally equidistant with equiangle available.

 

Transmission

The transmit fan is split in several individual sectors with independent active steering according to vessel roll, pitch and yaw. This will place all soundings on a "best fit" to a line perpendicular to the survey line, thus ensuring a uniform sampling of the bottom and 100% coverage.

The sectors are frequency coded (30 to 34 kHz), and they are all transmitted sequentially at each ping. The steering is fully taken into account when the position and depth of each sounding is calculated, as is the refraction due to the sound speed profile, vessel attitude and installation angles. Pulse length and range sampling rates are variable with depth for best resolution, and in shallow waters due care is taken to the near field effects. The ping rate is mainly limited by the round trip travel time in the water up to a ping rate of 10Hz.

 

Transducer arrays

The EM 300 transducers are linear arrays in a Mills cross configuration with separate units for transmit and receive. The arrays are divided into modules that may be replaced by a diver. The arrays are 1 degree beamwidth for receive and transmit. The physical array lengths are 3.3 meters. A combination of phase and amplitude detection is used, resulting in a measurement accuracy practically independent of beam pointing angle.

Hyrdosweep DS Mapping System

The Hydrosweep DS System is manufactured by Krupp Atlas Elektronik of Bremen, Germany.

System Description

The name ATLAS HYDROSWEEP comes from "HYDROgraphic Multi-Beam SWEEPing Survey Echosounder".

 

The equipment is used for hydrographic survey of areas in shallow, medium depth and deep sea regions. Display and recording of morphological structures are in the form of area presentations in color video and as isoline presentations. For postprocessing, two magnetic tape recorders are provided for storing the positon and depth data. In addition, there is a serial interface for transferring on-line measured data in realtime to a postprocessing computer system.

 

The ATLAS HYDROSWEEP Equipment belongs to the family of multi-beam sweeping survey systems with a broad coverage of 90 degrees perpendicular to the ship's longitudinal axis. It is thus possible to measure 59 depth values with a single sounding. Coverage is a width of about double the vertical depth if the bottom is level.

 

One special feature of the ATLAS HYDROSWEEP Equipment is that, in order to determine the sound velocity, the 59 depth values can be measured parallel to the ship's longitudinal axis. This is called "calibration mode".

 

By means of this special calibration method, the mean velocity of sound is determined over the water column. Sound refraction effects in the slanting beams are compensated. In the calibration mode, the transmitting and receiving functions of the system are swapped between the two hydroacoustic transducer arrays.

 

Note: Hydrosweep raw data files are stored on the "indian" server in the /tgt-data/hysweep directory.

Structure of the Equipment

The HYDROSWEEP Equipment mainly consists of the following:

• Two Hydroacoustic Transducer Arrays SW-6050-A-001. They consist of several individual modules, and are installed in a "T" configuration.

• The Transceiver Electronics, which is installed in three Electronics Cabinets SH-6020-A-001, SH-6020-A-003 and GE-6012.

• The Control/Display Console BD-6002, on which the measured values are displayed on a color screen, either as a cross profile view or as a contour layer display. The operating procedure and the input of parameters take place via a functional keyboard and an alphanumeric keyboard. The display of numerical data takes place on a display terminal.

• The Bottom Mapping Recorder PT-8: a printer/plotter which generates an isoline presentation of the morphology.

• Two Magnetic Tape Drives with computer, GE-6017 and GE-6018. They record the parameters, the measured depth values, and the position values supplied by connected equipments.

• The Display Unit AZ-6043 (an option), which serves as a slave display for the color display on the Control/Display Console.

 

The external signal-interfaces, provide the input/output interface between the HYDROSWEEP Equipment and the other equipments.

These data and signals are as follows:

• Position data from a navigation system.

• Course angle ("heading") from the gyro compass or from a sensor platform.

• Speed parallel to and perpendicular to the ship's longitudinal axis.

• Roll angle, pitch angle and heave information from a sensor platform.

• Sound velocity information from a measurement sensor (if connected) in order to acquire the velocity of sound at the transducer location.

Together with the measured depth values, these data are stored on a magnetic tape, or are processed computationally for on-line calculation of the isoline presentation on the plotter.

Bathymetric & Sub-Bottom Profiling System

The BATHY-2000 is manufactured by Ocean Data Equipment Corporation (ODEC) of Fall River, MA.

Introduction

The BATHY-2000 system provides high performance bathymetric survey and sub-bottom profiling capability. The system configuration is extremely flexible and can be easily modified to accommodate the specific needs of individual customers.

R/V Thompson Configuration

PDDD-200U	Precision Display and Depth Digitizer
CESP IV	Correlation Echo Signal Processor
LPT-5	Linear Power Transmitter
MOS-2000	Mass Optical Storage Device
TR-109	3.5KHz Transducer
TC-12/34	12/34 KHz Transducer
EPC 9800 (2)	Hardcopy Devices

System Overview

The following paragraphs will provide an overview of individual system components. Each BATHY-2000 system component has been designed in such a manner as to emphasize performance and flexibility.

PDDD-2000 (Precision Display and Depth Digitizer)

The PDDD-2000 provides the main control, display and storage function for the BATHY-2000 system. The operators interface is a large high resolution, sixteen color monitor and full keyboard. The operational display provides integrated sounding data and programming menu. It is capable of fully automatic as well as manual operation. The PDDD-2000 provides a hardcopy interface via a parallel port to a 16 level gray scale thermal recorder. The system is capable of real time display of sounding information as well as simultaneous depth digitizing, hardcopy and digital storage. A SCSI interface to a 1 Gigabyte WORM drive is available to store time/position tagged sounding data for a comprehensive digital record of the vessel's survey mission.

 

The PDDD-2000 is packaged within a sealed/ruggedized 19-inch rack mount enclosure. The main processing elements are two embedded 80486 microprocessors. One CPU handles serial I/O while the other handles data acquisition and processing. The PDDD-2000 receives processed data from the CESP IV via an IEEE-488 interface, depth digitizes and processes the data so that it can be displayed and stored on optical disk.

CESP IV (Correlation Echo Signal Processor)

The CESP IV is the signal processing element of The BATHY-2000 system. It is packaged within a sealed 19 inch rack mount enclosure. The CESP IV design utilizes an extremely flexible/reprogrammable DSP architecture. This benefits the user by allowing him the ability to alter many of the CESP IV transmit/receive signal processing characteristics. For example, the user may select between linear FM or CW pulse modes of operation. In the linear FM mode of operation the user may select sweep bandwidths of 1 KHz, 2 KHz and 4 Khz. The user may also select between FM sweep durations of 25, 50 and 100 ms. CW pulse mode of operation allows for various pulse durations with matching receiver bandwidths and waveform shapes.

 

Transmit signal synthesis provides modulation and pulse shaping capability as well as pre-distortion of replica waveform to equalize transducer effects. The analog front end provides AGC which expands the usable dynamic range of the unit to 144 dB. The signal processing hardware utilizes the latest technology including Intel's Pentium 4 processors.

LPT-5 (Linear Power Transmitter)

The LPT-5 is a five kilowatt 19 inch rack mounted linear power amplifier. It utilizes pulse width modulation switching technology. This topology of amplifier, digitally samples the input signal at greater than five times its own frequency with the resultant digital wave train being filtered to reconstruct the original signal at the amplifier output. This results in an efficiency rating of greater than 80% at full rated power. The operating duty cycle is 20% at full power with a 1-50 KHz frequency response. The LPT-5 offers greater than 70 dB operating dynamic range. It receives it's input waveform and control signals from the CESP IV via a ground isolated interface. A transmit/receive switch allows for complete isolation of the amplifier output stage for low noise operation. The LPT-5 is totally protected against adverse loads, over temperature, out of band input signal and loss of primary power.

MOS-2000 (Mass Optical Storage Device)

The MOS-2000 optical storage device utilizes magneto optical drive technology to provide permanent storage of up to 1 Gigabyte. The storage media is removable and allows for portability between systems. The recording formats are flexible and allow for storage of all required survey information and data tagging. Stored sounding data is fully processed.

TR-109 (3.5 KHz Transducer)

The TR-109 is a 3.5 KHz transducer suitable for bathymetric and sub-bottom profiling applications. These transducers are generally assembled into an array of multiple elements to provide added power capability and achieve desired beam patterns. The transducer is rated at 200 watts continuous power and has a nominal impedance of 125 ohms. The 3.5 KHz transducer on the R/V Thompson is an array of 12 series/parallel wired TR-109 elements.

TC-12/34 (12.0/34 KHz Transducer)

The TC-12/34 is a dual frequency transducer capable of both 12 and 34 KHz operation suitable for bathymetric survey applications. It is rated at a maximum power level of 2000 watts at 12 KHz and 500 watts at 34 KHz.

Note: the BATHY 2000 system does not support 34 KHz operation.

Hardcopy Devices

The BATHY 2000 is capable of interfacing to a variety of industry standard hardcopy devices. The table below lists the devices and their performance characteristics.

R/V Thompson Configuration

Device Type	Technology	Display Area	Resolution
EPC 9800 (2 each)	Grey Scale Thermal	19.84 inches	200 DPI

WinFrog Integrated Navigation System

WinFrog Software is produced by Thales GeoSolutions (Pacific), Inc.

WinFrog Applications

The WinFrog integrated navigation and data management software is suitable for a wide variety of applications in marine, land, and air environments and is now being used for numerous applications on over 400 vehicles worldwide:

• Fleet Monitoring

• Remote Vehicle Tracking

• Cable and Pipelaying Operations

• Bathymetric Surveys

• Geophysical Surveys

• Seismic Surveys

• Drill Ship/Rig Positioning

• Land Surveying

• Real-Time Aeronautical Vectoring

Though these are some of the more common applications, the potential use of WinFrog in any environment is unlimited. The WinFrog suite of programs continues to evolve and develop as users find new applications for the system and as new computer, data acquisition, and data processing systems come onto the market.

Win Frog Features

The Win Frog integrated navigation software consists of a "core" package with several add-on modules that allow the choice of a final system configuration best suited to the particular positioning and processing requirements. The core WinFrog package contains features that are beneficial to all uses; while the features provided in additional modules typically apply to specific applications.

Core Package

Graphics

Separate windows are provided for graphics, vehicle control, device control, track following, and quality control. Multiple windows may be opened and controlled independently. It is also possible to have multiple instances of the same window for use on different workstations. WinFrog supports the display of vector and raster data, i.e. shorelines, hazards, and navigation charts. Vector data can be imported in a variety of formats including DXF, DWG and DGN files or electronic charts, while raster data is imported in a number of common graphics formats or as electronic charts and can be used to provide a level of visual detail not obtainable with vector charts

alone. Several different layers of chart and graphics can be displayed simultaneously in the Graphics window and can be toggled on and off with a button click. The chart, like the vector display, can be scaled, panned, and rotated. In some cases, the chart color scheme can be changed to provide optimal contrast between the chart and the vector display or to enhance visibility at night.

Devices

WinFrog supports over 300 different peripheral devices, with the capability to simultaneously use over 30 devices, including multiple copies of the same device. Device data can be received in either industry-standard NMEA or customized formats. Alphanumeric windows display the raw data for each device configured in WinFrog. WinFrog serves as a data management system by collecting and distributing data for an entire project. Raw data for each device can be logged for future calculations, processing, and playback.

Vehicles

WinFrog supports the configuration of multiple vehicles, each using different peripheral devices. The calculation of each vehicle's position can be independently defined. Each vehicle can have its own shape and offsets, track its own waypoints, and line track. Events can be generated by anyone of the multiple vehicles and raw device data for each vehicle can be logged for future use. Alphanumeric windows for each vehicle are user-configurable to display various parameters, such as position, speed, heading, course of advance, waypoint and line track, and cross track error.

Extension Modules

In addition to the Core WinFrog package, there are several extension modules to augment WinFrog's capabilities.

GPS Calculations Extension Module (GPS Calcs)

The GPS Calculations Extension Module of Win Frog provides multiple reference station DGPS positioning by combining raw pseudoranges and RTCM differential corrections in a weighted position solution. Kalman filtering and user-defined DOP gates can be selected to smooth data and reject spikes inherent in the GPS measurement system.

Extensive quality assurance of the DGPS position is achieved through the use of UKOOA standard statistical testing. The Calculations window can be used as a real-time display of various statistical testing and GPS calculation results, including vessel position, statistical position error and residuals, satellites used with their elevations, signal to noise ratio, differential corrections, age of differential corrections, and dilution of precision values.

WinFrog has the capability to perform visual quality control checks on some of its functions. In the Calculations window, which was designed for QNQC purposes, you have the ability to view time series plots for all input and output data types and to monitor the data quality. The type of data viewed in a window, the scale of the data being displayed, and the width of the display window are all user-definable.

Multiple Vehicle Positioning and Telemetry Extension Module (MVP& T)

The WinFrog integrated navigation system supports a sophisticated, wireless, inter-vehicle telemetry network that enables position information from remote vehicles to be transmitted to other vehicles in the network. This ability is available in the Multiple Vehicle Positioning and Telemetry Extension Module. Each vehicle has the capability to transmit its own position as well as receive and display the positions of other vehicles in the network, all in real-time. Position information for each vehicle can be recorded at anyone vehicle or at all of the other vehicles. Vehicle positions can also be monitored by transmitting observed raw pseudorange data to another vehicle. The remote WinFrog system will then calculate that vessel's position from the pseudorange data and available RTCM information. In addition to transmitting position information, files and RTCM corrections can be transmitted between vehicles in the network.

Controlled Remote, lBl Acoustics, and Cable Management

WinFrog supports the use of one site controlling the operation of a remote site. The WinFrog Controlled Remote Tug Telemetry Extension Module enables one central WinFrog system to control a series of remote WinFrog systems. This is useful for a project utilizing a barge with several anchor handling tugs.

WinFrog supports the use of long baseline (LBL) acoustic technology. The Win Frog LBL Acoustics Extension Module provides the ability to calibrate and utilize LBL systems to enable accurate real-time positioning of a vehicle far below the ocean surface.

The Win Frog Cable Management Extension Module, in conjunction with the Cable Route Design Database, enables modeling and monitoring of submarine cables during cable lay operations. This software assists cable lay personnel with decisions regarding ship speed, cable tension, and cable payout speed to reach design goals.

Conductivity/Temperature/Depth Profilers

Information on the Realtime CTD Profiling and Water Sampling System is available at: http://www.seabird.com/products/profilers.htm