FAQ

If you do not find an solution to your problem below, please contact Aqua Visions support team at support@aquavision.nl.

Dongle License problems

After upgrading our license/version, we get a dongle error.

The error message means that the security dongle of the ViSea software cannot be found.
This can be caused by several things:

  • The security dongle is not attached to a functioning USB port of the PC.
  • The Windows drivers for the security dongle are not correctly installed.
  • You are trying to run a new software version but you have not upgraded your SMS or you have not upgraded the dongle when you upgraded your SMS.
  • The dongle is otherwise damaged/corrupted.

In case the security dongle is attached, you can see that the dongle drivers are correct if the little LED light on the tip of the dongle is on. If the light is not on, then the client should try to reinstall the dongle drivers. This can be done by starting the setupdrv program that is located in the ‘DD’ folder on the ViSea installation CD. First try setupdrv with the dongle NOT attached, or if not successful with the dongle attached.

If you want to install the driver for a parallel dongle, you should run the setup program but with an additional command line argument, so in a command prompt or with the start->run option of the windows start menu. The command to run is:
‘setupdrv /par’

Only registered and licensed user (hence when you have a valid SMS) can upgrade to a new version. If you have a valid SMS, but have not upgraded your security dongle, you should do so to be able to use the new software version. On updating your SMS, you should have received the procedure how to update your security dongle.

If the problem persists, please contact us, and inform us about the exact dongle error message, dongle serial number, VISEA software version and license number, and we will be better able to pinpoint the problem and help you out.

Can I run VISEA without a dongle?

No. The dongle is part of the software license, and is needed to run the program. However, it is not needed for installation and during the first 30 days after installation, or when you run the software in demo-mode.

My dongle is lost or physixally broken. Can I get a new one?

Yes, please contact Aqua Vision to purchase a new dongle.

How do I move the ViSea DAS program to a different folder on my computer?

That is possible. However, cut/paste won’t work. You will have to uninstall the software from one folder, and re-install it in the other.
You might also need administrator rights on your computer to move your software around.
Make sure the name of the destination folder doesn’t have any strange characters in it.

Can I get an updated version of the ViSea Software?

If you are a registered and licensed user of ViSea software, hence if you have a valid SMS, then you are entitled to receive new updated versions of the ViSea software free of charge. We will send you a download link to get the new software, as well as a short procedure on how to update your security dongle. If you are not sure whether you really need the update, ask for the latest release notes.

After installation, my computer gives an error concerning the MCR?

The MCR installer is a 3rd party installation, needed for running our software. Our installation tries to let this installation go automatically. However, sometimes it fails. Retrying the installation or running the MCR installer might work. It might also be necessary to restart your computer after the installation procedure. The MCR installer is located in the MCR folder on the installation media.

Do I need to have Matlab installed on my computer?

No. Our software contains all the necessary code and libraries for it to work.

After working without errors in the past, my computer gives an MCR/DLL error after the program started up correctly.

This is caused by a corrupted temporary folder named something like C:\Users\username\AppData\Local\Temp\username\mcrCache#.#.

Remove all subfolders within this folder to fix the problem.

Does the demo version contain all functionalities of the full version?

Yes. The difference is that the demo version only works for 30 days after you installed it, and you can install it only once.

ViSea DAS - Measurement Settings

My ADCP is connected, but DAS can’t connect to it.

Try to connect to it through BBTalk. Also, close off BBTalk before starting DAS, otherwise BBTalk will occupy the port. Checking the baud rate might also work.

How does ViSea calculate battery/storage capacity in burst mode, using TB/TC commands?

The calculation of storage capacity in ViSea does not account for the TB/TC commands.

However, because this is all about grouping the pings/ensembles of a measurement, you can use an equivalent measurement setup only for calculating the required battery/storage capacity (but not for the measurement of course), with the use of TP/TE commands.

For example if you want to group 120 ensembles (TC) of 1 second duration each (TE) into a burst which repeats every 10 minutes (TB), the battery/storage capacity should be equal to using a continuous measurement of ensembles of 5 second duration each (TE) without a burst setting (keeping the ping time TP constant), because you are then using the same number of ensembles (and pings) in 10 minutes time, but are dividing the spare/wait time over all ensembles.

My results seem unrealistic/ have spikes/have gaps/have a lot of noise/look weird?

There are many sources for measurement errors. Most often, it has to do with measurement circumstances (weather, waves, turbulence, strong density gradients, etc.), low quality positioning / heading / pitch / heave / roll data, faulty setup (beam obstruction, air bubbles, faulty cable, corrosion etc.), unknown ADCP commands, interference from other acoustic devices etc.
What can help with displaying noisy data, is averaging over multiple (e.g. 2 or 4) ensembles. You can also simply remove an entire ensemble in the STB by pressing x.

However, this doesn’t solve the root of the problem.

If you cannot find the source of the errors, send us a copy of the measurement data, plus other relevant data (ADCP commands, gps logs, measurement circumstances, etc), and we will take a look.

The ADCP doesn’t respond to the WakeUp message/ the output from the ADCP is unreadable.

When the ADCP does not respond to the WakeUp message, there could be something wrong with either the power supply, communication cable, comm. port of the PC or cable connector to the ADCP, or in worst case with the ADCP itself.

There are several things you can check yourself:

  1. Change the serial break length to 500 in the expert transect settings dialogue box and retry WakeUp
  2. Try using different baud rates
  3. Use BBTalk to send a break
  4. Change to a different comm-port on the pc and in ViSea, and retry WakeUp
  5. Change to a different pc, and retry WakeUp
  6. Check the cabling and ADCP power supply
  7. Take the power off the ADCP for a short time, then reconnect the power. This should generate a wake-up message.
With which ADCP-commands is the ADCP running?

You can view the ADCP settings in ViSea DAS via the toolbar option [Settings – ADCP]. You can use the CR1 command to revert the ADCP to its factory default settings.

What are the most important ADCP-commands for measuring currents?

First of all, a complete overview of all available ADCP-commands can be found in the Workhorse Commands and Output Data Format Manual.

The commands that are useful to remember are:

WN = number of cells beneath the ADCP
WS = cell size in cm
TE = Time between ensembles
TP = Time between pings
WP = number of pings per ensemble
BX = maximum tracking depth
EX = coordinate system to which the ADCP converts the current data

What is Correlation Magnitude, and why is it low in my case?

The Correlation Magnitude is a measure of the quality of the incoming echo at the ADCP. ViSea just presents it, and doesn’t do any calculation on it. Low correlation magnitude can be caused by for instance strong turbulence, vegetation, or other obstacles.

What is ERRVEL?

This is the Error Velocity, given directly by the ADCP, and contains the difference in vertical velocity components of two opposing beams. Thus, it is a measure of the consistency of the velocity measurement of the ADCP and the homogeneity of the flow field. If the Error Velocity is high, this means that the flow field changes significantly in the space between the beams.

My Blanking Depth seems to be larger than the depth given in the Blank after Transmit (WF) command?

The blanking depth is not only determined by the value of the WF command. It is also a function of the depth cell size (WS), ADCP depth, and the speed of sound.

Can I use one computer with ViSea DAS to collect data from two ADCP’s at the same time?

Yes, By using two ADCP’s as Master and Slave. Be sure to let the ADCP’s ping after each other, in order to prevent them from interfering with each other.

If I measure in Beam Coordinates, what should be my number of pings per ensemble (WP)?

Optimally WP1. Higher values will result in errors if your heading changes a lot.

For salinity, should I use the highest or the lowest salinity I measured?

During measurement it doesn’t matter what you fill in because you can always change it afterwards in the reprocessing. We recommend an averaged value of the salinity.

Why is my Bottom Track absent? (or other Bottom Track problems)

That could either be because the beam from the ADCP can’t reach the bottom, due to the frequency of the ADCP (higher=less range), or due to high sediment loads which attenuate the beams. It could also be because you’ve entered command BP0, which switches off the Bottom Tracking.

In post-processing, the effects of bad bottom-tracking can be bypassed first of all by referencing to GPS data (reference: NAV). If even the bottom depth is missing, it might be an idea to reprocess the data with some kind of artificial bottom depth data entered as a depth sounder (this still requires reference: NAV).

Why is there a difference between the GPS-track and the bottom track?

This is most likely an effect of an offset between the compass and the ADCP outlining. The Compass Calibration procedure is designed to fix this.
Another cause could be a so-called ‘moving bottom’, which means that currents and sediment transports near the bottom are so high that the entire bed seems to be moving.

Can ViSea DAS/STB interpolate data?

No. However, ViSea DPS can interpolate data.

What is the unit of the velocity sticks? What depth do they refer to? What direction are they referenced to?

The length of the sticks don’t have a specific unit.
The velocity sticks are depth averaged over the whole profile.
The velocity sticks are earth referenced.
You can change their scale in the PlotSettings-menu under ‘Settings’.

How is the bottom depth determined in ViSea?

If no depthsounder depths are decoded at Ch1 the ADCP depth is determined by the averaged value of the ADCP bottom track depths. In case you do have a separate depth sounder, and in case you have decoded the depth at channel 1 (Ch1), the ADCP depth will be overwritten by the depth sounder depth. For this reason we advise to decode depth sounder depths at channel 2.

For upward looking ADCP, ViSea DAS can detect the surface and eliminate the bins beyond it.

ViSea-H/HCT: how is the value for WL computed?

The Water Level (WL) is the vertical position of the H-ADCP (user-defined) plus the water column above the device measured by the H-ADCP.

What is the color code for the sensor buttons in the lower right of the screen?

The red button color means the port is not open, green means data is steadily being received and yellow means that ViSea has not received data for some specific time. This might indicate that a sensor has stopped sending data.

How can I apply the Edge Discharge Calculation?

For this you need the STB (Survey Toolbox), and two waypoints to define a track. You can import a bottom profile in the STB of ViSea by opening the STB and selecting ‘Processing Survey’ and ‘WayPoints’. You can either import a file with waypoints, or you can place them with your mouse pointer in the STB. Then you choose 2 points with the same ID in the table in the STB. Click close (The STB will save the file as WAYPOINTData.txt in the project directory /Data/WAYPOINTData/). The discharge side extrapolation will be recalculated if you just go to ‘Processing PDT – Hardware – Apply’.

Can ViSea deal with Self-Contained upward looking data?

Yes. ViSea will automatically detect when it’s upward looking. Bottom track will become Surface track. ViSea even has a special Self-Contained Toolbox, if you have the appropriate license.

Can ViSea deal with large data files?

There is no file size limitation. What might help in speeding up output, is changing the output from ASCII to ‘mat’-files in the ViSea.ini file.

What is ‘Side Lobe Affected Area’?

The acoustic beam of an ADCP transducer has side lobes besides the main central beam. The echoes from these lobes are usually much weaker than the echoes from the central beam. This has one exception; when the side lobe ‘bottom’ echo reaches the transducer at the same time as a ‘water column’ echo from the central beam, they are of comparable strength, and the ADCP cannot tell them apart. The cells near the bottom for which this happens are said to be within the ‘side lobe affected area’, and their data has to be discarded. This only happens when the beam is pointed at an angle towards the bottom or surface. If the angle increases, the affected area becomes larger. A vertical beam has no side lobe affected area.

My internal pitch/roll/heading data is inaccurate or missing.

ViSea can post-process with data from an external pitch/roll/heading sensor, but this has to be available, preferably with an NMEA-encoded ASCII-string.

Can I connect devices over LAN?

Yes, but be careful that these devices are not blocked by any kind of firewall.

External devices are connected, but DAS is not receiving data.

Check that the comm-ports are open and available and receiving data. Also checking the baud-rate might help.

What ADCP-depth should I use for a bottom-mounted upward looking ADCP?

You should use the depth below the water surface at which the ADCP is mounted. ViSea DAS will automatically recognize it’s an upward looking ADCP.

Can I make ViSea export its output in real time to another program, like Qinsy?

Yes. Follow these steps:

  1. Open ViSea DAS
  2. Select File->Collect Data
  3. Select Settings -> Load Settings  (select the settings that are used for your current measurements.)
  4. Select Settings -> Communication -> Add -> New. Give a random name for your virtual port, for instance ‘OutputDevice’, and click ‘Ok’.
  5. In the next screen, select a port with a high number, for instance COM41. Set IO Mode to ‘Output’ and write down the Baud Rate. Each Baud Rate is OK, but it needs to be entered later in Qinsy. Refresh Period should be ‘0’. Click ‘Next’.
  6. In the next screen, click ‘Select Driver’. A dialog screen opens in the folder ‘C:/Program Files/Aqua Vision/ViSea4/Drivers’. If this is not the case, navigate to this folder. This folder contains the file ‘ASCIIout PD8.txt’. Select this file as driver and click ‘Open’.
  7. The Setup-screen closes automatically. The Communication Setup menu now contains ‘OutputDevice’. Click ‘OK’ to finalize.

If done correctly, the software now sends out an ASCII-string over COM41 while collecting data. Other programs should be able to read this string.

ViSea DAS - Driver Issues

Do you have drivers we can use? Can you make a customized ASCII-output driver?

Yes, we have a lot of drivers for decoding GPS, OBS, CTD, and we can help you find the right one. If you have Software Maintenance Service (SMS) with your license, we can write an ASCII-output-driver to your specifications.

How can I edit my own input driver?

Chapter 5 of the VISEA-DAS manual explains how. (paragraph 4.2 for the PDT manual)

How can I edit my own output driver?

Paragraph 7.5 of the VISEA-DAS manual explains how.

How do I get the NAV referenced data in my ASCII output, instead of the Bottom Track?

To get Nav referenced data in the *.t file, just change all _BT in the ascii out driver to _Nav, so e.g.: VelocityData_BT becomes VelocityData_Nav.
To get ref none data, just omit _Nav or _BT.

What is the unit for current velocity in my ASCII output?

By default, the output is in cm/s. If you wish, you can change it in the output driver in the following way. The BLOCKDATA has lines like:

‘VelocityData_BT’ [1] [100] ‘%7.1f’ [7] ‘ -32768’ EAST VELOCITY COMPONENT

The number in the third column (100 in this case) is the factor used to multiply the velocity. So, in this case the velocity would be multiplied by 100, resulting in m/s instead of cm/s

What is the general structure of a driver?

The driver consists of a definition of what is to be put in the three sections of the ASCII file: The Header (once at the top), the Leader (line with data per ensemble), and the Block (profile data for all cells within an ensemble).
Before each leader there is a line defined between the de LLINESTART and LLINEEND keywords, with a summation of the variables which will be printed.

For instance, for the variable Total Flux, the definition contains the name of the variable, the index (always 1 for single variables), the scaling factor (usually 1), the print format, the minimum length, and the error flag:

‘TotalFlux’ [1] [1] ‘%13.1f’ [0] ‘ 0’

Can I connect multiple external devices using Auto Decoding?

For convenience with general format messages like NMEA messages used for GPS (GGA/VTG/ZDA/GLL) and Heading (HDT) for example, we introduced the AUTO NMEA decoding.

This functionality is activated by the keyword AUTO in the format field of the driver and the @ symbol in the name of the driver.

For this auto decoding, you only need to specify which parameters you want extracted from the message from the sensor and ViSea will figure out the format of the message automatically, because it is well known NMEA format.

Please note that for the auto decoding, there is indeed a general container of parameters for all auto decoding activated sensors, meaning that all parameters that are set for all the sensors that where set as auto decode will be looked for in all messages of all these sensors.

It is possible to have a mix of decoding methods for different sensors, in the way that each sensor can have its own decoding driver (either one of normal or auto decoding).
The normal driver decoding is working for only the specified sensor, but the auto decoding works for all auto decoding sensors together.

So, every sensor can have its own driver, but if you connect two similar sensors, each of which puts out a GGA string for example, and you decode them all with auto decoding, then you get two (possibly confusing) readings of geographical position.

If you would like to do that specifically (have two sensors with the same NMEA messages decoded) and not get their output confused, you should set only one to auto decoding and the other to normal decoding and use different parameter names for each.

What do all the numbers in the header of a T-file stand for?

The structure of a ‘T’ output-file is determined by the ASCIIout driver. Look in the ‘drivers’-folder belonging to ViSea for the standard ASCIIout driver text file. Inside this text file the contents of each line of the T-file are explained in detail.

How do I switch between input drivers for an external device?

The process to apply a different driver file is the following:

  1. Load the raw data file you want to process in ViSea DAS. (Make sure you use the settings corresponding to the transect)
  2. Go to ‘Settings’ -> ‘Communications’
  3. Select the external device and click ‘Edit’
  4. Do not edit the next screen and click ‘Next’
  5. In the next screen, click ‘Select Driver’ and select the relevant driver file.
  6. Click ‘Test’ (nothing will happen, but it will allow you to click the Finish button)
  7. Click ‘Finish’
  8. Now reprocess the raw data file (File -> (Re)Process). When asked whether you want to read the external sensors again, say ‘Yes’.

ViSea DAS - GPS Issues

Can ViSea DAS read my gps device?

Yes. ViSea DAS is capable of automatic decoding NMEA sentences from gps devices.

How should I apply the Compass Calibration during measurement?

The compass calibration cannot be updated in Collect mode, only in Playback mode. The procedure we follow:

  1. Start DAS, and wake up the ADCP.
  2. Start sailing the track. Sail it as straight as possible.
  3. Start recording,
  4. Stop recording after some distance.
  5. Playback the track in DAS.
  6. Open the Compass Calibration window,
  7. Look for a stable offset,
  8. Click the ‘Apply new Offset’ button.
  9. The offset is now saved under ‘Transducer Misalignment’

It must be noted that all the settings in the Transect menu can also be changed during playback / reprocessing afterwards. When you playback data the found offset will be applied instantaneously and the Nav and BT tracks should be on top of each other.

My compass calibration requires an unrealistic salinity for the tracks to match up?

You can try different things:

  • It can be, that you lost the bottom track in this track, then you have a different length in the 2 tracks (GPS and BT). You can try using another track for the calibration and looking if there is still the same problem.
  • Instead of a ‘y’ you can also type in an own sound speed like ‘1450’.

You should check, if there is a time delay in the GPS and correct it.

Do I have to perform the compass calibration routine for each individual transect file?

There is no need to perform the compass calibration for each individual file.Usually you take 1 track, recorded along a more or less straight line and with constant speed, determine the offset and use that value to reprocess all data.

How do I reprocess data with a different gps-driver?

The procedure is as follows.

1. Playback the *r.000 file

2. Click [Settings]–>[Load Settings] and load the metainfo file of this track. This is to replace some other settings that you may had selected before from other measurements.

3. Now click [Settings] –> [Communication].

4. Select [GPS], click [Remove]

5. Click [Add] and select [GPS] click [Next]

6. No need to change port settings, click [Next]

7. Click [Select driver] and select the @NMEA_GGA driver. Boat Speed and course are now calculated by ViSea. Since you also get a VTG string form your GPS you could also select @NMEA_GGA&VTG. Then the Speed and Course as given by your GPS will be applied. Click [Test] and [Finish]

8. Click [File] –> [Reprocess] and select the *r.000 file.

9. The new driver will now be applied and you will get a negative Longitude.

The speed and/or direction from my GPS seem(s) wrong.

You can manually edit the driver to only read the lat-lon coordinates, and not the speed magnitude and direction. To do this, you will need to edit the decoding string. It should only read the lat-lon coordinates. From these coordinates, ViSea will calculate the speed and course. With the standard (NMEA) driver, the speed and course will be taken from the GPS device.

There is a delay between my GPS and my ADCP.

You can enter a delay value in seconds in the Communication menu under ‘Settings’.

How is the speed of sound determined?

There are several options:

  1. The speed of sound is calculated by DAS from salinity, temperature, and water depth. The salinity can be measured using a CTD, or entered manually.
  2. The speed of sound is measured directly with a Sound Velocity Probe attached to DAS.

The speed of sound is entered manually in the Transect menu.

PDT - General

Can I measure sediment concentration with an ADCP? What is PDT?

Yes, you can. PDT is our Plume Detection Toolbox, designed to convert acoustic backscatter into suspended sediment concentration after calibration with water samples.

What is ViSea STAR?

STAR (Sediment Transport Analysis Routine) is a simplified stand-alone version of the PDT. STAR is made for quick and easy analysis of measurements in small fresh water streams and water channels using data acquired with Teledyne RD Instruments RiverBoat, StreamPro or RiverRay ADCPs.

Can I calibrate a CTD/OBS in ViSea without an ADCP attached?

No, the ADCP has to be attached for ViSea to work. The ADCP doesn’t have to be in the water, though.

Can I apply PDT on old datasets without OBS or SSC measurements?

No. The PDT calibration requires water samples or data from a well calibrated OBS, taken at the same time as the ADCP-survey, in order to compute SSC from acoustic backscatter.

The environmental parameters are unknown. Can I still use PDT successfully with the default values?

Yes. However, the environmental parameters become more important with high sediment concentration. For concentrations less than 1000 mg/l they are not very important, for higher concentrations they become important because they are used to calculate the backscatter attenuation due to the sediment.

Can the PDT handle self-contained ADCP-data, e.g. from a bottom mount?

Yes. The PDT will automatically know it’s self-contained data, and will present it accordingly.

Is there a reference for computing sediment concentration from backscatter?

Additional information on the conversion from internal counts to dB can be found in :

http://www.rdinstruments.com/rr/reports/echopaper.doc

Further information can for instance be read in:

Hoitink, A.J.F., Hoekstra, P., 2005. Observations of suspended sediment from ADCP and OBS measurements in a mud-dominated environment. Coastal Engineering 52, pp. 103-118.

Gartner, J.W. 2004. Estimating suspended solids concentrations from backscatter intensity measured by acoustic Doppler current profiler in San Francisco Bay, California. Marine Geology 211. pp. 169-187.

How is the sediment flux calculated, and how is it extrapolated to the top and bottom?

The ‘TotalFlux’ is the summation of all flux data in a track, including the unmeasured top and bottom part. To best explain the flux calculation you first have to focus on the way discharge is calculated, after that the calculation of flux is a straightforward step, simply multiplying concentration with discharge.

The cumulative flux also includes an extrapolated part at top and bottom layer, the same way the discharge is extrapolated. The flux at each bin is calculated as discharge for that bin (Q-cell) times concentration for that bin, likewise the extrapolated flux at top layer is calculated as extrapolated discharge at top (Q-top) times the concentration at topmost valid bin, and the extrapolated flux at bottom layer is calculated as extrapolated discharge at bottom (Q-bot) times the concentration at the nearest-to-bottom valid bin. The method for discharge extrapolation at top and bottom, which directly translates to the method for flux extrapolation, can be selected in the ViSea DAS transect settings (linear or exponential method).

The flux or concentration measurements at the top few bins can be influenced by disturbances due to boat interference, which can be seen in the ADCP’s echo intensity signal as very high intensity values locally. You should remove the measurement results at these locations during validation process.

How is the distinction made between positive and negative flux?

In ViSea (DAS, STB, PDT), the sign for flow, discharge or flux indicates direction of flow, in this way:

For any transect, when facing forward along the track (looking from start to end of vessel track), the positive flow (discharge or flux) is to the right.

This is dependent on the vessel path/course, hence when you travel along the transect in the opposite direction, the sign of your measurement will change (if the flow itself has not changed).

Furthermore, in the ViSea STB/PDT, you can set waypoints on each side of a transect as a pair with the same name and then the sign will be related to these waypoints and positive will be depending on the choice for left and right bank (red and green waypoint) as when you would be on a river with positive flow always downstream.

Can you also apply the PDT on a horizontal ADCP?

Yes, we can! With a special version of the PDT, called PDT-H. This toolbox can also extrapolate the flux to the entire cross-section.

Can ViSea DPS handle concentration data?

Yes. With the proper toolbox and license, DPS can make presentations for the concentrations and fluxes in the same way as for flow.

PDT - Combining ADCP / OBS / CTD data

Should I correlate the acoustic backscatter to the OBS or the water sample data?

We have developed the protocol to use the water sample data for ADCP backscatter calibration because we get better results from it. We only use the OBS as a reference (comparison when available for selected areas or depths). The OBS does allow for real-time calibration during the measurement, although this is not as accurate as post-processing with water samples.

However, you can still choose yourself what you want to use to calibrate the ADCP backscatter: OBS or water sample data. You can do that by selecting the right correlation plot type in the correlation plot window and select Recalculate (menu of STB: Processing PDT->Iteration->Correlation Plot).

How do I get an ADCP file opened in the PDT? How do I get OBS/CTD data in there?

You can use the r.000 files for processing in the PDT.

To get the ADCP files in the PDT do the following:

– Open the PDT
– Click [New Project]
– Playback an r.000 file in ViSea DAS.
– This file will be added to the PDT.

These steps can also be found in the PDT-shortguide.
Further information can also be found in the manual.

When you playback the ***external.dat, this data is automatically read, containing reprocessed data from OBS/CTD etc.
When you reprocess it will read the original ****comlog file containing the raw external data and will decode it.
In that case you will need to have OBS/CTD defined in the communication setup with correct comports.
If you load one of the original metainfo-files all this information will be there.
Note, in case you have reprocessed the data these metainfo-files will be overwritten, so make sure you then load the original metainfo-file.
(that’s why we always recommend to store the raw data as is and make a copy before you go reprocessing.

In the PDT, how do I add the water sample data?

You create a PDT project by playbacking the ADCP data. Then you can add the water samples by selecting the correct ensemble and select add water sample (or SHIFT-S). The depth of the sample is relative to the waterline (positive = down). The use of  water samples is straightforward and needs no special attention (make sure you write down the time and depth you sample!).

Does my OBS need to give output in mg/l?

No. The software reads in Turbidity in any form; SSC, NTU, raw counts, Volts, Ampere. In the software you specify coefficients to convert the collected Turbidity data to SSC. So, if you have an OBS sensor outputting SSC these coefficients become 0 offset, 1 as scaling. If the sensor outputs NTU the software lets you calibrate the Turbidity values to SSC by making use of water samples, through linear regression forcing the line through 0,0.
If the sensor outputs raw counts the software lets you calibrate the Turbidity values to SSC by making use of watersamples, through linear regression.
Note, the coefficients can also be specified manually.

Is it better to fit the backscatter/OBS relation through the origin?

Yes, but only if the OBS has registered in NTU.

My ADCP-data has a lot of noise?

Averaging over more than 1 ensemble can smooth your data.

Can I use multiple OBS sensors for the calibration?

Yes. You can add multiple OBS sensors in ViSea, just decode the values from the second OBS as ‘Sensor Depth2’ and ‘Turbidity2’.

Can I use OBS data not acquired by VISEA DAS?

Yes. That has to done by renaming the OBS data files to the filename convention of ViSea (com.log file). Also the timestamp format must be the same as in ViSea. If your transect ID is for example testabc, then the ADCP-files will be testabc001r.000, etc. The OBS data files must be renamed to testabc001com100.log for instance. Then in ViSea a new device (OBS) must be added in the communication setup at comport 100 and with the correct decoding string. During reprocessing the OBS data file will be ‘read’ and reprocessed as in real-time, and the data will be used.

How do I get the OBS to send data to ViSea?

You start the OBS first with the OBS software, and then connect it to ViSea.

How can I export the backscatter coefficients derived from the correlation plot?

The values for these coefficients are stored in the metainfo_PDTProjectName.mat file in the PDT project folder. You can also make a screen capture of the iteration screen using SHIFT-P.

What salinity/temperature value should I enter if I don’t have a CTD in the water?

In the Environmental Processing settings in the PDT you can freeze the values from earlier measurements (Freeze Profile).

Can I use an OBS/CTD from brand X?

You can configure the CTD as normal in ViSea in the communication as long as the CTD has an ascii string output. You just need the depth or pressure and the turbidity/conductivity (what you want to read). It doesn’t matter what kind of OBS or CTD it is. If the CTD gives a salinity value, then this value is used in ViSea for computing the sound speed according to the Unesco formula. If the CTD doesn’t give salinity, ViSea computes salinity using the conductivity.

PDT - Measurement Setup

Where should I position the OBS?

Ideally, somewhere in the water column directly below the ADCP (for ship mounted survey), but outside the ADCP-beams.

Where/when should I take the water samples? And how many?

It is desirable to have as many samples as possible (but at least 3), with a nice spread in concentrations, but at least take samples when you deploy and recover the instruments. If there is a high sediment event to be expected (storm/dredge disposal) you are advised to take additional samples.
Take water samples at the same depth as the OBS and at least at 3 different depths, at 1/3 and 1/2 the water column and approx. 3 meters above the ADCP. Be sure to keep outside the blanking depth and side lobe affected areas of the ADCP.
Keep good track of the time, location, and depth of your water samples, so that you can link them accurately to a specific bin in your ADCP-data.

Which beam should I use for calculating the sediment concentration?

The sediment calculations in ViSea PDT are done for only one beam because there is only one beam closest in location to the other measurements (OBS profiles, water samples) that are needed for sediment calibration. You can select the beam with the best orientation also with respect to the ship if you expect distortions from the ship or environment. Note that for velocity (3D) measurements you need at least three beams, but for sediment you need only one. We at Aqua Vision usually use a vertical beam from a second ADCP, because it has virtually no side-lobe affected areas.

How do I establish the noise floor (‘Er’ in the Settings -> Hardware screen)?

You can establish the noise floor by doing the Receive path test and read the values at High Gain RSSI. This is the PT3 command with a WorkHorse.

What type of OBS do you recommend?

We use OBS3A’s from Campbell Scientific. They have been tested by the Dutch government and came out positively. Also, the 3A type provides conductivity, temperature and pressure simultaneously.
So, when lowering the OBS3A you get a temperature/salinity profile which is used for calculation of water attenuation. The OBS3A can also be deployed in self contained / recording mode.

Where do I find the RSSI scale factors?

As for the RSSI scales, you can ask for these coefficients from Teledyne RDI by sending a request to their fieldservice department notifying the ADCP serial number.
These values are instrument specific and they are constants for each specific instrument.

Which salinity measurement should I use?

ViSea DAS requires the salinity at the transducer head for the Doppler calculation.
The STB/PDT requires a depth profile of the salinity in order to calculate the sound absorption.

My top cells look messy.

The top cell(s) looking odd is a known issue, and because the iterative process in the PDT goes from top to bottom, these cells influence the entire profile. One way to work around it is to set the ‘fix first bin’ value to something higher than zero, in order to discard the values in these cells.

How do I get a nice top view of the concentrations in the STB?

In the Survey Toolbox (STB), in the menu bar, go to Settings -> PlotSettings. Here you can change the value of TopView -> LineWidth to a larger number, which will represent the width along the track that will be colored. Try a value of ‘5’ or ‘10’ first and see if the result is what you are looking for. Make sure that the ShipTrack LineWidth is (much) smaller than the TopView LineWidth, or else you will not see the desired result. Also, make sure that Transparency is set to ‘1.0’.

Coordinate Systems

Why does not show my background in the STB?

The coordinate system of the background map has to be the same as the data’s. ViSea supports DXF, DWF, and KML files.

What type of coordinate system is displayed?

ViSea DAS and PDT display and plot against the coordinates that you receive through your GPS device. If the GPS is WGS, then the coordinates will be Lat&Lon, and ViSea and PDT display Lat&lon.

Why do the exported ascii files give coordinates in a coordinate system I don't recognize?

The position in the ASCII file are the same as in the (very old) Transect Format. The format is: Latitude and Longitude in SECONDS.

Can ViSea export to Google Earth?

ViSea-4 STB has the possibility to export the main screen as an overlay in Google Earth.
Note, it is just a screen capture that will be exported, with limited resolution, but can be nice to put in a report.

My longitude and Latitude have strange quantities.

Longitude and Latitude are displayed in seconds, so if you have decimal degrees, all you have to do is multiply by 3600 to get the coordinates in seconds.

Miscellaneous

What are the hardware requirements of my operating system to run ViSea software?

What are the hardware requirements of my operating system to run ViSea software?

  • Windows XP, Vista, 7 or 8
  • Pentium PC 1 GHz or higher recommended
  • 1 GB RAM or higher recommended
  • 450 MB of free disk space, plus space for data
  • 2 serial ports (4 recommended)
  • Display resolution of 800 x 600 (1024 x 768 recommended)
  • CD-ROM drive / writer / flash drive
  • License dongle
  • Administrator rights / write permission on the installation folder
Is ViSea compatible with Windows Vista/7/8/64 bit/etc.?

Yes, as of version 4. For older versions, be sure to check the Windows Compatibility to Windows XP:

1. Navigate to the ViSea program file in the program folder of ViSea.

2. Right click the executable of ViSea and select properties.

3. Then select the [compatibility] tab and set the [compatibility mode] to [Windows XP].

4. Confirm this and try using ViSea to see if your issues still appear.

5. If this did not help then you can also try the options [disable desktop composition] or [disable display scaling] on the compatibility tab.

Can I run ViSea on Linux?

Sadly, no; ViSea is compiled for Windows only.

Can I use ViSea to process data acquired using WinRiver?

Yes. ViSea is compatible with the WinRiver Software, or any other Teledyne RDI ADCP-software. ViSea can read files of type .PD0, .ENR, .ENX, .MMT, and a whole lot more.

Are there differences between results from ViSea DAS and Teledyne RDI software like WinADCP or Velocity?

In general, results are the same from each software package. There are minor differences which are caused by the bin mapping algorithm and the fact that ViSea DAS doesn’t neglect blanking and applies more accurate linear interpolation. For more information on this comparison, read the following document: Comparison ViSea DAS with Velocity.pdf

Can the ViSea Software handle data from the new Sentinel V or RiverPro?

We always try to keep up with Firmware and Hardware updates from Teledyne RDI, like StreamPro, RiverRay, RiverPro etc. The implementation of the Sentinel V dataformat is scheduled to be implemented in our next release.

Can I use ViSea with Sontek or Nortek equipment?

No. Our software is solely compatible with Teledyne RDI ADCP technology.

How much does your software cost?

At your request, we will send you a quotation.

We have specific needs. Can we get a customized version?

Yes, at additional cost.

ViSea DPS can’t read my Riverray data.

Riverray has a special format which the older versions of DPS can’t read. Upgrade to the latest version of DPS, or in ViSea DAS you can replay the *.PD0 format. That shouldn’t be a problem. If you reprocess the data in ViSea DAS you can use the output files for further work in the DPS.

In DPS, what are 'VISA' presentations?

The VISA presentations are based on a projection of the data onto a theoretical track.
This means that you have to define a line from start to end of the intended transect of measurement, and then the presentations will plot the data as if you were travelling along that line (data projected on nearest point along the line).
Please note, the ‘VISA10 Discharge’ presentation calculates a discharge curve for a tidal period and hence requires data of a complete tidal period tobe available, or it will give an error.
The ‘VISA10 Transect’ and ‘VISA20’ presentations present each transect individually, and ‘VISA30’ presents up to 5 transects on one page.

Can we make a suggestion for improving your software or increasing functionality?

Yes, by all means. We value customer feedback, and aim to improve our software to accommodate customer requests.

What is the difference between a soft break and a hard break?

A ‘Break’ signal puts the ADCP from Standby into Command mode. A Break is ‘hard’ (from ‘Hardware’) when it is sent through the power supply. A Break is ‘soft’ (from ‘Software’) when it is sent by the command ‘===’ in the input prompt. In wireless self-contained applications, only soft breaks can be sent, unless you have a soft-to-hard-break-converter.

Can I measure waves with an ADCP?

Yes. You will need a specialized ADCP, called a Teledyne RDI Waves Array, and maybe a processing array called NEMO.

Does an ADCP require calibration?

No. The ADCP measures current speed directly via Doppler shift, and not by any other proxy. It is required to know or calculate the speed of sound, however.