SeaTrac USBL Setup

Acoustic Limitations 

The operational ranges and performance of the SeaTrac USBL system depends heavily on environmental and geographical factors in which the system is deployed. These environmental factors include changing water temperature, dissolved oxygen content, marine plant life, and man-made acoustic noise from passing vessels and/or other submerged equipment. Geographical features that affect the performance of the SeaTrac system include depth of the channel, acoustic reverberation of nearby structures, obstacles that may block acoustic transmission, magnetic interference from large ferrous structures, the topside beacon mounting method, and orientation and movement of the topside beacon.

Favorable conditions to achieve the best performance of the SeaTrac system include:

• Open water with no impurities (solids or gasses in suspension)

• Consistent temperature throughout the transmission channel (no thermoclines causing refraction effects that can reduce the operating range)

• No other <100kHz acoustic transmission sources in the water

• Ambient noise level of less than 90db

• Less than 10deg/5sec of rotational motion and less than 80deg/10sec

• Suitable distance from large ferrous structures

Best Practices for the SeaTrac USBL

When deploying the SeaTrac system in a new environment, always re-calibrate the magnetic heading of the system for the best results. The internal heading system is quite sensitive to sources of interference so re-calibrating would help reduce this error. Please see the sub-section “Setting Up the Topside Beacon” to calibrate the magnetic heading.

When deploying the beacon into the water, you should ensure that the beacon is at least 1.5 to 2 meters away from the nearest side wall and 1.5 to 2 meters below the surface of the water (and above the sea floor). Side walls can cause acoustic reflections and can seriously impact the performance of the system, resulting in big position jumps due to the way in which the incoming sound is received by the beacon. 

When the beacon is hanging vertically down in the water, it is advisable that a rigid pole and mounting fixture be used to stop the beacon from swaying in the current. 

Always make sure that the ROV is “below” the beacon horizontally in the water (in deeper water than the beacon). If the remote beacon mounted to the ROV is shallower, then the sound will potentially have to pass through the “main” transducer ring or body of the beacon which will cause computational issues. 

The ROV must also be further away from the beacon than it is deep, there is a blind spot of sorts directly bellow the beacon in the shape of a 45 degree cone.

The diving angle of the ROV can also cause position jumps. If the ROV is diving in a direction/angle which causes the beacon on the ROV to be “shadowed” by the ROV, then it is possible for the SeaTrac to use reflected sound which will not only have an incorrect range (due to extra delay) but also the incoming angle of the sounds will be incorrect with respect to the position of the ROV. It is advisable that the ROV be allowed to hover at periods in order to get an accurate, reliable position throughout the dive. 

Another important factor in accurate operation is the volume of water in which the system is being used. When the SeaTrac performs a “ping”, there is enough energy to flood a 75-meter area. If the area is shallow and narrow, the sound will likely still be present when the ROV beacon is attempting to respond which will cause inaccuracies. 

Another factor that can affect the performance of the SeaTrac system is noise in the environment. The internal heading system is quite sensitive to sources of interference. These sources of interference could be outboard motors or on-board generators which could be vibrating sound into the water area local to the beacons. Typically, a background noise of around <90dB gives the SeaTrac a good operational “signal-to-noise” window in which to operate. Noise levels in excess of 105/110dB will again cause significant issues when tracking. 

When using the SeaTrac USBL system on a Deep Trekker™ PIVOT, the integration of a DVL system will greatly improve the navigational accuracy of the USBL system. A DVL system will help interpolate the position of the ROV in the water when sources of acoustic interference or loss of a GPS signal are present. This will make the navigation display on your controller smoother and more accurate.  If the SeaTrac system is used on a laptop, the benefits of the sensor pod and DVL will not be present.

SeaTrac USBL Components

The Deep Trekker™ SeaTrac USBL consists of two main components, namely, the X010 beacon (mounted on the ROV) and the X150 beacon (connected to the ROV controller or Windows PC). Other components are:

• a Teledyne Impulse MCBH series socket and 20m deck-lead, cable.

• Pole mounting bracket.

• M4 x 8mm cap-head screws - for securing the beacon to the pole mounting bracket.

• Rare-earth Neodymium magnet - for magnetic reset-to-defaults function).

• SeaTrac Software USB Drive.

• User Manual (does not include setting up with controller, only with windows PC)

• Transit Case

Setting up with the BRIDGE Controller

Follow these steps to set up the SeaTrac system with the Deep Trekker™  Bridge Controller

Download the quick start guide below or watch the setup video

• Plug the topside beacon into the power outlet on the controller or to the power brick provided with the SeaTrac and insert the power brick into an outlet. Look for a flashing green light on the topside beacon to ensure it’s being powered

• Plug the USB connector into the controller

• Navigate to the Location menu:  MENU → SETTINGS → LOCATION

• Scroll down to the Device Type button in the ‘ROV’ section and ensure the selection is ‘SeaTrac beacon’. This setting will be saved even when you reboot as long as your external GPS is still plugged in. Because we’re using a SeaTrac beacon there are a few new settings to adjust:

• Beacon ID: The default ID of the ROV beacon is 2

• Water salinity: Choose between fresh, salt or a custom PPT value 

• Data filtering: Filter out poor-quality data at the expense of data frequency

• Select Beacon Setup to begin calibrating the beacon

• Calibrate the internal sensors by moving the beacon through every possible orientation until the ‘Buffer Level’ shown on the popup reaches 100%. To do this, imagine you’re painting the entire inside of a globe with the top of the beacon.

• Press ‘Save Buffer’ to save the calibration value.

• This saved buffer will now give you a Calibration Quality reading that can be seen on the right side of the Locations page. Ensure this reads 95% or above. If not repeat calibration.

• Once the buffer is saved, set the beacon down on a stable surface for 30-60 seconds to allow for settling of sensors before deployment.

• Ensure the Water Salinity setting reflects the body of water you’re piloting in. This can be set as ‘Fresh’ (0 PPT), ‘Salt’ (35 PPT) or a custom value.

• Lower the beacon below the surface of the water making sure that it will be fixed 1.5 to 2 meters below the surface of the water

• Finally, fix the beacon in place if possible

Once the USBL is connected to the controller, its status is indicated on the USBL icon on the top bar using the following colors: Red (PING FAIL) no GPS lock or zero line of sight, Yellow (PING BAD) transceiver has poor line of sight to ROV, Green (PING OK) GPS locked and USBL signal is good

CONTROLLER GPS

The controller has an integrated GPS module which is activated as soon as the controller is turned on. This is used to get the global position of the controller and is fed to the USBL system in order for it to calculate the position of the ROV. If you have an external GPS device, you can also use it for your controller’s location instead. 

The controller will show a GPS icon in the top bar of the screen that will display the number          of satellites you’re connected to and the quality of your position lock. It can take several minutes to lock on to satellites.

If the icon is shown in red this means your GPS device is not sending data and there may be something wrong with it. If the icon is shown in yellow this means the coordinates your device is providing are inaccurate and you may need to wait or reposition yourself to a more open environment. The controller’s location can also be set to ‘Static GPS’ which allows you to manually enter the position of the controller instead of using the built-in GPS module.

To set it as ‘Static GPS’:

• Navigate to the LOCATION settings page

• Change the DEVICE TYPE under the ‘Topside’ section to ‘Static’

• Either manually enter your latitude and longitude coordinates or set the position using the controllers’ navigation map. Finding your coordinates can be accomplished on most mobile map applications such as Google Maps. (On your mobile device, zoom in on your location on the map.  Press and hold with one finger on your location to drop a pin. The latitude and longitude will be displayed at the bottom of your mobile device screen).

USING AN EXTERNAL GPS

External GPS devices can also be configured to provide location data for either your Controller or ROV:

• Plug your external GPS device into the controller’s USB port

• Navigate to the LOCATION menu:  MENU → SETTINGS → LOCATION

• Scroll down to the DEVICE TYPE button in the ‘Topside’ section and ensure the selection is ‘External GPS’. If you want to use it as your ROV’s location set this in the ‘ROV’ section

• Select CONFIGURE DEVICE

• In the SERIAL PORT dropdown, select the GPS device you’ve plugged in

• In the BAUD RATE dropdown select the correct baud rate for your device. If you’re using the SeaTrac supplied external GPS, set this to ‘4800’

• Once the serial port and baud rate are configured correctly you will start to see data flow, signifying your device has been set up successfully.

CONTROLLER WI-FI

For the USBL system to be used with the controller and display a geographical map on the screen, a Wi-Fi connection is also needed. Without Wi-Fi connection, the USBL will still function, however, the geographical features to be shown on the map cannot be loaded.

The Nav package comes with a USB Wi-Fi dongle plugged into one of the USB ports on the controller. This can be used to connect the controller to a Wi-Fi network. Follow the following steps to connect the controller to a Wi-Fi network:

• Open MENU → SETTINGS → NETWORK SETTINGS → WI-FI.  Toggle WI-FI to ON.

• Select and click Wi-Fi Network to view a list of available networks. Ensure reasonable distance from the router.

• Select your network.  Enter your password and hit enter.  If the network has no password, hit enter without entering any characters.

If the network connection is good, a Wi-Fi symbol will appear at the top of the screen. If the network is not connected or the internet is not available, a Wi-Fi symbol with a slash through will appear at the top of the screen. If there are two networks available with the same name, the system will automatically connect to the network with the strongest signal. If the system tries to connect to a preferred network and the password has been changed it will automatically forget that network and sit idle waiting for instruction. As an alternative to using Wi-Fi, an ethernet cable with connection to the internet can be plugged into the controller with no further steps required.  The system will automatically connect to the internet.

If a Wi-Fi connection is not available at the dive site, map tiles can be preloaded by connecting to Wi-fi, and statically selecting the dive site location. Ensure to navigate around the area at different levels of zoom to collect as many cached map tiles as possible. There is a limited amount of internal memory available for this.

Setting up With BRIDGE App

Follow the same steps as above for connecting the hardware to the tablet controller or your pc.

Setting topside location 

• Once the system is connected navigate to the locations menu of the BRIDGE App

• Select external gps or static as the top side position

  • If selecting static, The position can be chosen on the map.

  • If selecting external gps the device will need to be configured. 

  • Select the proper Comm port or USB location

  • Set the baud rate for the GPS Puck: 4800

Setting Vehicle location

• Select SeaTrac USBL as the vehicle position

• Select configure device and ensure that the proper usb or comm port is selected

• Set the baud rate for the SeaTrac USBL: 115200

• Once positional data is flowing in the messages box the system is communicating properly

Setting up With Windows PC (PinPoint Software)

• Download and open the SeaTrac PinPoint software using the provided USB stick or by visiting this link: https://www.blueprintsubsea.com/SeaTrac/support

• Power on the topside beacon by connecting the barrel connector to your hand controller or to the power supply connected to an outlet.

• Open Device manager on your computer and expand the line labeled “Ports (COM & LPT)”

• Connect the X150 Beacon to the computer with the USB plug.  The Device manager should automatically refresh.  Under Ports you should see a new line labeled “USB Serial Port (COM #).  Take note of the number next to COM.  In this example, the computer has selected COM 11.

• Right click on this device and select “properties”.  Click on the “Port Settings” tab and change “Bits per second” to 115200 and click OK.

• Connect the supplied GPS module to your computer. 

• The device manager should refresh again, and you will see a new line “Prolific USB-to-serial Comm Port (COM #).”  Take note of the number next to COM.  You can always distinguish between the X150 and the GPS antenna in your device manager because the GPS antenna is always “prolific”. 

• Right click on this line and click “properties”.  Click on the “port settings” tab and set bits per second to 4800 and click OK.

• Open the SeaTrac PinPoint software and click the gear shaped button in the bottom left of the screen which opens the settings menu.

• The first tab is an Application Setup page which will allow you to choose units of measure, format for coordinates, manually adjust declination and choose the location of log files.

• Navigate to Beacon Setup by clicking on the second tab shaped like the X150 beacon. This menu allows you to set up all the different beacons used in the underwater network. The SeaTrac system is capable of tracking fifteen separate beacons, but for use with Deep Trekker™ ROVs we will only use two.

• The system will always have an X150 present by default. Double click on this beacon to open the settings menu. Set the ID number and salinity. Freshwater should have a salinity of 0ppt and oceans should have a salinity of 35 ppt.  You can fine tune this value if you have data on the water you are operating in. You can also change the name of the beacon to Topside to make the map readout clearer.  Click OK to save these settings.

• Deep Trekker™ systems will have pre-set the X150 beacon ID 15. You can verify this by watching the green LED on the X150 beacon flash once it has been powered. The beacon will cycle through a 2 second flash followed by a series of short flashes equal to the ID number followed by a pause and then it will repeat.  You should count 15 short flashes.  If you count a different number, choose that value in the ID number drop down menu.

• Click on the plus button to add the beacon mounted on the ROV. Set the ID number to 2 and select X010 Beacon from the dropdown menu. Additionally, ensure the Maximum Fit Error is above 0 otherwise the system will not accept any location pings. Click OK to save these settings and add the beacon.

• Navigate to the Device Setup menu by clicking on the wrench icon. This menu is for setting up all the devices that are directly connected to the computer. Click the ‘Auto Detect’ button and PinPoint will automatically fetch the connected beacons/GPS devices and their COM ports/baud rates. Ensure these port numbers and baud rates match the ones reported in the device manager.

• Navigate to Platform Setup by clicking the boat icon, and then to USBL Beacon Offsets.

• Measure the distance from the GPS module to where the beacon will be suspended in the water on the XY plane where the X axis is North/South.

• Below is an example of a potential setup with measurements.  

• Enter these measurements in the USBL Beacon Offsets. Press OK to save these changes.

• Exit the settings menu.

• Click the Tracking Mode symbol in the top left of the main screen to turn on the GPS tracking mode on the PinPoint software.

• It will highlight blue when the “Tracking Mode” is enabled. If there are any issues with the USB devices connecting, pop-up windows will appear. Double check that you have entered the correct com port value and that the baud rates in device manager are set correctly.

• Navigate to the X150 window by clicking on the beacon icon on the left-hand side of the screen. 

 • Click the “clear buffer” button on Magnetometer calibration. If this setting is disabled, navigate to the Diagnostics page on the left menu bar and enable Diagnostics Mode.

• Calibrate the internal sensors by moving the beacon through every possible orientation until the ‘Buffer Level’ shown on the popup reaches 100%. To do this, imagine you’re painting the entire inside of a globe with the top of the beacon.

• Press the Calibrate button in the SeaTrac software to save the buffer data and finish calibration. After you click “calibrate,” the top bar will give a measure of calibration quality.  If this value is below 90%, clear the buffer and start over.

• Once the buffer is saved, set the beacon down on a stable surface for 30-60 seconds to allow for settling of sensors before deployment.

• When complete your location should be displayed.

• Click on the Map on the left-hand side of the screen.

• You can zoom in and out by scrolling as needed.

• There are 3 different marker options that are available to use on this screen:

• Single Point of Interest: Places individual markers when turned on.

• Path of Points: When toggled on, places markers and connects them in a path. 

• Once these points or path of interest are finalized, you can view these points by navigating to Settings > Marker Setup.

• In this menu, you can select the point of interest or path that you have just created and then select the setup button on the left side of the screen to edit them.

• In this setup view, you can change the fields as needed or edit the latitude and longitude coordinates of the points of interest you have created. Select the check mark in the bottom of this window once all fields have been confirmed.

• Now in the ‘Marker Setup’ window, you can select the ‘Export’ button in the bottom left of the window to export your file.

• If you wish to import a GPS file into the pinpoint software, click the ‘Import’ button in the bottom left of the ‘Marker Setup’ window and select the file to import. KML, KMZ, GPX and OLEX files are supported.  Similarly, points can be exported as any one of these file types.

If the X010 modem on the ROV is not connecting with the X150 topside beacon, or your positional data is poor, there is a diagnostic screen on the PinPoint Viewing Software.

Diagnostics

If the SeaTrac system is behaving in an unexpected way or it is not working as it should be, the following diagnostic procedures can be taken to isolate/identify and solve the problem. This section is divided into three parts to better isolate the issue: Using SeaTrac through the Deep Trekker™ controller, using SeaTrac through the Blueprint Pinpoint software and a Common section. The Pinpoint software contains more in-depth diagnostic tools than the Bridge Controller.

USING DEEP TREKKER™ CONTROLLER

Procedure: Connect X150 (top-side beacon) to the controller power outlet (or other power supply). Make sure the beacon is powered up by looking at Status LED flashing green. Connect the beacon to the controller through the USB connector.

Verification: USBL icon should appear on the top bar of the controller screen. 

Procedure: USBL icon circle should turn to yellow or green when communicating with the beacon on the ROV. When both controller and ROV are turned on, and the SeaTrac beacon is plugged in, hover the X150 beacon a couple of inches above the beacon on the ROV (mouth to mouth). Transmitted sound frequencies should be heard and the USBL icon should change colors indicating the communication. If the icon never changes color and stays at RED:

• Check that the X010 Modem on the ROV is powered and has an ID of 2 (this might require unmounting the modem). Look for a flashing green LED next to the electrical connector. The modem will cycle through a 2 second flash followed by a series of short flashes equal to the ID number followed by a pause and then it will repeat.  You should count 2 short flashes. If you count a different number, you will need to use the SeaTrac tools software included in the SeaTrac PinPoint software download to change this value. Contact Deep Trekker™ Support for help with this procedure, changing any settings outside of setting the correct ID value can prevent the system from functioning.

• If step 1 is not the issue then the X150 beacon can be reset to factory defaults by doing the following:

• Turn off, then turn on the power to the top-side beacon and check it has booted into the main application – the status LED on the base of the beacon housing should be flashing green. The beacon should be connected only to the power supply.

• Hold the “reset magnet” (a small magnet that comes in the SeaTrac box) over the magnetic sensor at the base of the beacon.

• As the magnet is moved into place, the green status LED should start quickly flashing red to show the presence of the magnet.

• Hold the magnet in place for 5 seconds until the status LED stops flashing, and becomes permanently illuminated red. At this point the defaults have been applied. Remove the magnet.

• Cycle the power to the beacon to ensure the default settings are re-applied to hardware.

 Verification: USBL icon should change colors to yellow or green indicating successful communication with the ROV beacon. 

Procedure: Connect the X150 USBL beacon to a power supply (either from controller or other) and connect the beacon also to the controller through using the USB connector. Navigate to the SETTINGS > SEATRAC page on the controller. Press ‘Start Calibration’ and follow the instructions.    

Verification: The ‘Buffer Level’ should increase towards 100% as the beacon is rotated. While rotating the beacon, it is helpful to imagine that the surface of the mouth is painting the inside of a sphere. 

Please refer to the common section below

USING SEATRAC PINPOINT

This is most likely an issue caused by selecting the wrong COM port on SeaTrac Pinpoint, or the baud rate (bits per second) is set incorrectly in the device manager. Ensure that the COM port number entered in Pinpoint is the correct port for the correct device. This can be verified using ‘Device Manager’ and noticing the COM ports (unplugging the devices and noticing which COM port disappears).

When adjusting the COM ports entered in the Pinpoint software, it is important to turn off ‘Live mode’ which is located on the top left corner of the program.

Please refer to the common section below

Please refer to the common section below

• Navigate to the diagnostic window by clicking on the waveform icon on the left-hand side of the screen.

• Click on the “diagnostic mode” toggle switch to turn diagnostic mode on.

COMMON (BETWEEN DT CONTROLLER AND SEATRAC PINPOINT) 

There are a number of factors which can influence the accuracy of the positions - : movement of the USBL beacon in the water, affecting the attitude information which is used in the position computation algorithms; local magnetic interference which is "pulling" the heading off course; interference with the acoustic "line of sight" which is preventing accurate positions from being calculated. The last point is quite important as if line of sight is not achievable, reflected sound (boat hulls, solid structures, etc.) will be picked up by the receiver and the angle of the incoming sound will cause the resulting position to be incorrect.

The discrepancy could also be caused by an inaccuracy in the heading value, certainly the internal heading system is one area which can be improved with a steadier, in-place calibration however this is often easier said than done. One other thing to try - depending on hardware availability - would be to use an external heading system (from a boat, or otherwise). This external heading can be fed directly into PinPoint (using NMEA HDG/HDT data sets). This often provides a much more consistent and accurate reference.

● It's always worth re-calibrating the magnetic heading of the SeaTrac system when the operator is using the system in a new environment. The internal heading system is quite sensitive to sources of interference so re-calibrating would help reduce this error. Once calibrated, it is always worth verifying that the heading is accurate compared with something like an iPhone, etc.

● The X150 beacon can be powered from a 24V power source if available to isolate any power issues. If the position of the ROV appears to improve with the change of power supply, it could indicate that there is an issue with the original power supply. 

● When deploying the X150 USBL beacon, the end user should ensure that it is at least 1.5 to 2m away from the nearest sidewall and the same for the depth below the surface (and above the seabed). Side walls will cause acoustic reflections and can seriously impact the performance of the system, resulting in big position jumps due to the way in which the incoming sound is received by the SeaTrac X150.

● With the X150 hanging vertically down, it's advisable that a rigid pole and mounting fixture be used to stop the beacon swaying in current, however a rigid pole will deliver vibration from a vessel's engines to the beacon.  If one approach is ineffective, try the other.

● The ROV needs to be below the X150 topside beacon in order for the triangulation to be effective.

● If the ROV is in the blind spot directly below the beacon, good location data will not be generated. The horizontal distance between the beacon and ROV should always be greater than the vertical distance. Example, if the ROV is 20m below the beacon, it needs to be more that 20m away from the beacon horizontally.

● If SeaTrac Pinpoint software is accessible, before starting the tracking, it is worth running a "background noise analysis" which turns the X150 into effectively a microphone, listening for any sources of background noise such as: other sensors in a similar frequency range ~20 to 40kHz, outboard motors or any on-board generators which could be vibrating sound into the water area local to the beacons, etc. Typically, we expect to see background noise levels of around <90dB which gives the SeaTrac a good operational "signal-to-noise" window in which to operate. Noise levels in excess of 105/110dB will again cause significant issues when tracking.

● ROV diving angle can also cause position jumps. If the ROV is diving in a direction/angle which causes the beacon on the ROV to be "shadowed" by the ROV then it is entirely possible for the SeaTrac to use reflected sound as the "main" sound which will not only have an incorrect range (due to the extra delay in sound being received by the X150) but also the incoming angle of the sound will be wrong and hence the resolved position will be incorrect. It is advised that the ROV be allowed to hover at periods in order to get an accurate, reliable position.

Lastly, one other key factor in reliable, accurate operation is the volume of water in which the system is being used. When the SeaTrac performs a "ping", there is enough energy in the water to flood a 75m area. If the area is only shallow or not very wide, the chances are that this sound will still be present when the ROV beacon is attempting to respond. This will also cause issues related to positioning.