This document describes the HydrOffice Sound Speed Library and Manager (2019.2). For the source code, go here.

2.6. Appendix B - Connection Settings

2.6.1. Settings for data reception

2.6.1.1. Moving Vessel Profiler

The MVP controller interface can be configured to transmit data via UDP using a variety of data format and transmission protocols (Figure – MVP Controller configuration dialog. Boxes A through C are required for transmission of cast information. Box D can be configured to transmit sensor data.).

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Fig. 2.66 Figure – MVP Controller configuration dialog. Boxes A through C are required for transmission of cast information. Box D can be configured to transmit sensor data.

The MVP computer IP address and the IP address of the machine running the SSM package can be configured in Box A. For newer versions of the MVP controller, it is recommended to choose the NAVO_ISS60 transmission protocol as this will allow for large cast files to be transmitted in several packets without overflowing the UDP maximum packet size limitation (Box B). Older versions of the MVP controller software (up to version 2.35 to the best of our knowledge) do not support the NAVO_ISS60 protocol and the package must be configured to use the UNDEFINED protocol in the SSP package configuration file. The file format can be adjusted to accommodate a CTD with the S12 format or a sound speed sensor with the CALC or ASVP formats (Box C).

Note that the transmission protocol and file format must be configured in both the MVP controller interface and in the the Setup tab (in the Input tab, to activate the MVP listener and, in the Listeners sub-tab, for the communication settings).

Boxes D and E refer to raw instrument transmission settings that are configurable for future use. Since casts received from an MVP system do not have a filename embedded in the data stream, the Sound Speed package will name casts received using the following convention: YYYYMMDD_HHMMSS_MVP. The date/time stamp embedded in the filename will be the time of the cast.

Note

Once the MVP listener is activated, a “MVP” token will be visualized on the left side of the SSM’s status bar.

2.6.1.2. Sippican

There does not currently exist any internal mechanism in the Sippican software to broadcast data via UDP, this capability has been included to accommodate vessels that use UDP network broadcasts to log data from various systems. The expected data format is the Sippican native .EDF file format.

Note that a single Sippican data file can sometimes exceed the maximum buffer size for UDP packet transmissions. If software is written to transmit Sippican data files via UDP, this limitation should be kept in mind. The Sound Speed package currently only accepts transfer of a single UDP packet thus transmission software may need to reduce the data by thinning the profile. Received profiles will use the filename embedded in the .EDF.

2.6.2. Settings for data transmission

The Sound Speed package can be configured to transmit data to a number of systems by selecting the Transmit data button in the Editor tab.

For installations with multiple clients, the Sound Speed package will deliver the cast sequentially to all clients. Failure on transmission to one client will not interfere with other clients though it will slow down the transmission sequence through all clients for any clients who are timing out on confirmation of reception as the Sound Speed package will wait up to the ‘RX timeout’ value defined in the setup (default: 20 seconds) for confirmation.

Note

Server mode will only currently work with the SIS transmission protocol.

2.6.2.1. Kongsberg SIS

SIS does not require additional configuration to receive sound speed files since it always listens on port 4001 for input sound speed data.

The following indications are useful for monitoring reception of sound speed profiles:

  • The SSP profile filename will be updated in the Runtime parameters menu in the form: YYYYMMDD_HHMMSS.asvp. The date and time fields are populated based on the time stamp in the profile that was received from the SSP package. In the case of measured casts, this is the time of acquisition, as found in the input file. In the case of synthetic WOA profiles, the date/time is based on the time of transmission of the cast (using the computer clock where the SSP package is installed).

  • SIS creates several files in the last location from which it loaded a sound speed profile.

  • The SVP display window, if being viewed in SIS, will update with the new cast.

  • In the event that a cast is rejected, SIS will launch a warning dialog to indicate that the cast it received was rejected.

Although SIS will always allow incoming sound speed transmissions, it has several restrictions that must be observed in order for the data to be accepted (see Kongsberg manual). As this particular transmission protocol is used by other acquisition systems, it is worth describing in detail what the Sound Speed package does to the cast data to satisfy the input criteria for SIS.

The transmission procedure used by the SSP package will format the temperature and salinity profiles into the Kongsberg Maritime format. Since the WOA09/RTOFS grids only extend to a maximum depth of 5,500 m, the profile undergoes a final extrapolation to a depth of 12,000 m to satisfy SIS input criteria, this is done with temperature and salinity values measured in the Mariana Trench by Taira et al. (2005).

Since SIS input profiles have a limit on the maximum allowable number of data points, the sound speed profile is thinned using a modified version of the Douglas-Peucker line reduction method as described by Beaudoin et al. (2011). The algorithm begins with a small tolerance and increases it linearly until the number of points in the profile falls below the maximum allowed by SIS.

By default, the cast header is formatted to instruct SIS to accept the profile for immediate application without launching the Kongsberg SVP Editor. This behavior can be changed through the configuration file by setting Auto apply profile to False (in the Setup tab). In this case, SIS will accept the cast but will then launch its own editor interface and user interaction will be required on the SIS computer in order to have the cast applied to the multibeam system.

Once the cast has been prepared for transmission, it is sent to SIS via UDP transmission over the network. If SIS receives the profile and accepts it, it will rebroadcast the SVP datagram. The Sound Speed package waits for this rebroadcast to ensure reception of the cast. The profile that was re-broadcasted from SIS is compared against that which was sent. If they match, then the transmission is considered successful. If there is a discrepancy, or if no rebroadcast profile is received, the user is notified that reception could not be confirmed. The lower left status bar notifies the user of the various stages of this verification process.

In deep water, the rebroadcast event may take several seconds to occur and the software will wait up to a user-defined amount of time (e.g., 20 seconds) for reception of the re-broadcasted SVP. All other package functionalities are suspended during this wait period.

2.6.2.2. Hypack

The Sound Speed package can transmit data to HYPACK using HYPACK’s driver for Moving Vessel Profiler (MVP) systems (MVP.dll). Next figures provide a guidance on how to configure a Hypack project to receive data from SSP package.

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Fig. 2.67 Step 1: opening the project manager.

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Fig. 2.68 Selecting or creating a Hypack project.

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Fig. 2.69 Selecting the Add device button.

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Fig. 2.70 Adding device drivers to a Hypack project.

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Fig. 2.71 Adding the MVP device driver.

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Fig. 2.72 Configuring the MVP driver. The network parameters of the driver are configured to use a UDP input protocol in a client role. The host IP address must match the address used by the computer running SSP and the reception port must match the port configuration chosen in the package configuration file. The “Write Port” is left as zero.

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Fig. 2.73 Additional configuration of the MVP device driver.

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Fig. 2.74 Testing reception capabilities in Hypack. After having loaded a sample cast into SSP and send it, the profile should be visualized in Hypack (after clicking “Test” button).

2.6.2.3. QINSy

QINSy accepts the same SVP transmission protocol as SIS, but a method to verify reception of the cast is not currently known thus the user should confirm reception in the acquisition system.

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Fig. 2.75 Select Setup from the QINSy console after loading your project. Refer to QINSy documentation for information regarding setting up a project.

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Fig. 2.76 Edit your project database

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Fig. 2.77 Right click the Auxiliary Systems icon and select New System.

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Fig. 2.78 Configure the new system as shown above. Choose the same port number that SSP package will be sending casts to (this is configured in the __config__.db file).

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Fig. 2.79 Choose Echosounder Settings from the Settings menu. This will allow you to configure the behavior of QINSy when it receives new sound speed profiles from SSP package.

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Fig. 2.80 Left­click the icon for the SVP Editor device.

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Fig. 2.81 Choose appropriate options to control QINSy’s behavior when it receives casts from SSP package. For initial testing purposes, you should at least choose to be informed after a new update.

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Fig. 2.82 With QINSy “online” and recording, send a test profile from SSP package. If you have chosen to be informed upon reception of a new cast, a message window will appear for acknowledgement.

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Fig. 2.83 By choosing Echosounder Settings from the Settings menu again, you can verify that the cast was received.

2.6.2.4. PDS2000

PDS2000 accepts the same SVP transmission protocol as SIS, but a method to verify reception of the cast is not currently known thus the user must confirm reception in the acquisition system.

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Fig. 2.84 Adding an MVP driver to PDS2000.

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Fig. 2.85 Configuring the MVP driver for PDS2000.

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Fig. 2.86 Configuring an MVP driver for PDS2000. Be sure to scroll down in the list on the left side and choose the driver you added in the previous step before modifying the port number. The port number must match that which SSP package is sending data to (configured in the __config__.db file).

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Fig. 2.87 After the driver is added, test the device to verify correct configuration of communication protocols.

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Fig. 2.88 With the device driver open, send a test cast from SSP package. The data should appear in the Io port View window. Be sure that the correct device driver is selected from the top left list window.

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Fig. 2.89 While running PDS2000 in acquisition mode, right click in the multibeam raw profile display and choose “Multibeam filters”. Choose “SVP Sensor” as the source of sound speed profiles to be used.

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Fig. 2.90 While running PDS2000 in acquisition mode, you can verify reception in the Status displays and the “Raw Data” displays. Check the date, time, latitude, longitude against what you sent from SSP package.