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How to test the performance of your processing computer

Variation in specifications and performance of computers of course means that the choice of hardware can make a difference to the efficiency of your workflow.

Author: EIVA CEO Jeppe Nielsen

We decided to look into just how much a difference this is via the performance statistics gathered within the NaviSuite software product for data modelling and visualisation, NaviModel. The statistics proved to hold valuable information, and the answer is: a huge difference.

(Click to enlarge) Scatter plot showing S-CAN computation time (in seconds) versus size of data being processed (in points) where each plot is a single run of S-CAN

Comparing computer performance in connection with advanced subsea point cloud cleaning algorithm

When we released NaviModel 4.1, it came with an improved, much faster S-CAN algorithm. S-CAN is an advanced tool for automatic point cloud cleaning, developed in collaboration with the Center for Massive Data Algorithmics (MADALGO) at Aarhus University in Denmark.

This posed the perfect opportunity to dive into the effect computer specifications (especially in terms of RAM and disc size) have on the efficiency of software tools.

The above data was gathered from our own tests as well as those customers who have given consent to us using the data, during a period of 8 months. It covers more than 40,000 runs of S-CAN, and numerous different computers, covering the entire scale of specifications from poor to high performance.

When analysing the data, it becomes clear that:

  • There are big variations in computing time. For example, with 10 million points (10E6), we see performance ranging from 25 seconds to 600 seconds. This means that there are computers out there that are 24 times faster than the slowest computer used.
  • The performance of S-CAN is quite linear.
  • Most usages of the S-CAN tools are carried out with less than 30 million points, and the largest we have measured is 750 million points in a single S-CAN run.
  • S-CAN SCORE (blue plots – typically used for data sets with a single surface) is used more often than S-CAN COMPONENTS (green plots – typically used for data sets with multiple surfaces) among our users.

So what can we learn from this?
If you run S-CAN on a data set with for example 10 million points and measure the processing time, you can see from the graph how other machines are performing. If your results come in closer to the 600 seconds than 25, it is an indication that it may be worth your while buying a faster machine.

Learn more about NaviModel and S-CAN.

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Learn more about Correlation Velocity Log (CVL) a new approach to acoustic velocity logs for underwater navigation

The Tritech AquaTrak™ CVL provides greater precision and accuracy than a 1200kHz with the range exceeding a 300kHz DVL.

Underwater navigation is essential for a diverse range of Unmanned Underwater Vehicle (UUV) military and commercial applications. Although GPS and other radio signals have been widely used for surface vessel navigation, these technologies are ineffective for underwater navigation because electromagnetic signals are blocked by seawater. Inertial sensing is a suitable and widely used technology for underwater navigation. However, position error tends to drift in the absence of input from aiding sensors. The most successful combination for underwater navigation has therefore been to combine inertial technology with velocity measurement using acoustic sensors that measure speed from echoes reflected off the seafloor.

The Doppler Velocity Log (DVL) has traditionally been the standard choice for integration into UUV navigation systems. Until now Correlation Velocity Logs (CVL) have not affected this domination of the marketplace because of the high level of signal processing required for correlating pairs of signals in CVLs. However, recent advances in low power electronics and advanced
acoustic correlation signal processing techniques now enable CVLs to offer a superior price and performance value proposition over existing DVLs.

CVLs offer many advantages over DVLs, since they can achieve high accuracy at low velocities even during hover manoeuvres. DVLs use narrow beam widths, while CVL transmitters have wid
e beam widths. This gives CVLs the potential to use lower frequencies thus permitting operation in deeper water; increased accuracy; reduced power requirements for the same depth and smaller form factors.

CVL typical vertical beam                                                         DVL typical tilted beam 

                                                             

Tritech AquaTrak™ Correlation Velocity Log provides both long range navigation and high resolution accuracy. The highly flexible and modular design allows the unit to be used in a standalone configuration or as part of an Integrated Navigation System.

A CVL measures a two-dimensional displacement vector between two receiver channels for successive pulses, so that the corresponding velocity measurement is generated by the
displacement divided by the time interval between pulses, with no need for a speed of sound measurement.

AquaTrak’s piezocomposite transducers operate at 150 kHz enabling altitudes of 300m above the seabed. This operating frequency was selected as an ideal compromise between a deeper propagation of the acoustic pulses (due to the reduction in attenuation with decreasing frequency) while avoiding background noise at lower frequencies. The acoustic power requirements have also been minimized for UUV integration and operation — particularly for autonomous underwater vehicles.

To ensure that the incoming signals used within the correlation calculation result from bottom reflection rather than volume reverberation or background noise, AquaTrak uses advanced Synthetic Aperture Sonar acoustic correlation signal processing techniques. It first determines the height of the instrument above the seabed and uses time of flight calculations to neglect signals detected before this depth threshold.

The unit can therefore operate as an altimeter to verify other onboard instrumentation. The transmitted power is then automatically adjusted to take into account the attenuation of the returns from the seabed caused by transmission and absorption losses by the seafloor. The complex form of the correlation coefficient between two complex acoustic signals is then used by AquaTrak to generate velocity measurements.

The breakthrough in AquaTrak™ CVL was understanding how to use the SAS transducer arrays as a CVL in order to estimate with sufficiently high accuracy the three-dimensional velocity vector, giving the displacement between successive pings. The side-by-side comparison (shown below) of the forward ground speed given by a 300 kHz SAS used as a CVL and a conventional 600kHz DVL shows the much greater accuracy achieved by the CVL, which provides the evidence of the high potential of CVL technology.

 

 

Along-track velocity of a 600kHz DVL (in grey) compared to that of a ‘through the SAS sensor’ CVL operated at 300kHz, performing correlations in multiple (other colors) 2m range windows varying from 40m to 160m. The ground truth is provided by the quality of the SAS imagery which is focused for the CVL and defocused for the DVL.

 

 

 

Find out more information at Tritech.co.uk

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Get up to 85% off the price of NaviSuite software products for survey and engineering operations at sea.

Would you like to upgrade your current software spread? Now, you can benefit from the advanced features of the NaviSuite products at a vastly reduced cost with our trade-in offer!

 

NaviSuite constitutes a complete, advanced multi-purpose suite of software products for virtually any sonar and sensor survey or engineering operation carried out by offshore and shallow water professionals. It will streamline your business through reduced costs, increased efficiency and improved results.

 

What the trade-in offer includes

With the EIVA NaviSuite trade-in offer, you can get up to 85% off the price of the NaviSuite product(s) that match(es) your current software setup by trading the latter for NaviSuite licences. The discount depends on what software setup you would like to upgrade with a trade in.

The offer includes 1 year’s maintenance and 24/7 support as well as 1 year’s access to our eLearning training site. This will allow you to get a thorough introduction to the software and its features.

 

About NaviSuite – A complete software toolbox for shallow water and offshore survey and engineering

 

NaviSuite offers you…

A perfect match for small- and large-scale setups
… through scalability in terms of data set size and number of users

More flexible workflow and complete traceability
… through the use of raw sonar and sensor data throughout the workflow

More efficient data processing
… through various automatic features and analysis tools

High-quality end results
… through real-time quality control and sonar and sensor data overview

Easy integration with other software solutions 
… through import and export of standard data formats

Support of even the widest equipment spread
… through more than 400 sensor drivers

Future-proof investment
… with a maintenance and 24/7 support programme

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MACSEA Appoints New Business Development Manager

MACSEA has announced the joining of Leonardo Catanzaro as the company Business Development Manager for its Oil & Gas market sector.

Due to the continued growth of its Oil & Gas activities, MACSEA has strategically appointed Leonardo Catanzaro as Business Development Manager for its new commercial premises in Rio de Janeiro.

His main responsibilities will focus on developing MACSEA’s key customer relationships within Oil & Gas industry and seeking new business opportunities to support our Subsea Asset Integrity / Life-Of-Field business line. The company currently has a wide range of subsea equipment and software solutions throughout its partners globally that meets industry demands for cutting edge technology with cost effectiveness.

Leonardo Catanzaro has a solid background in Marine Sciences with professional and academic accomplishments in the Oceanography, Geology and Geophysics segments. His experience in the Oil & Gas industry, ranges from offshore work for Survey and Subsea Engineering and Offshore Construction. Where, he highlights the participation of one of the largest gas pipe-lay project in Latin America. As well as being the Sales and Business Development Manager for industry renowned manufacturer of subsea technologies. Most recently Leonardo has been acting as an independent survey consultant major Oil & Gas companies on projects for the pre-salt area offshore Brazil.

Antonio Felipe Silva, Commercial Manager at MACSEA commented, “We are extremely delighted to welcome Leonardo Catanzaro to MACSEA team, we have major growth plans for our Subsea Asset Integrity / Life-Of-Field business line which we hope that with Catanzaro’s potential to tackle complex sales will help us achieve our goals.”

Leonardo Catanzaro commented, “I am delighted for this exciting opportunity to further enhance MACSEA’s business in the Oil & Gas sector. MACSEA has a strong market reputation for world-class products and services it offers to customers locally. I hope to use my expertise to target new clients in this important market sector and also to add value to the Subsea Asset Integrity / Life-Of-Field solutions that MACSEA already has to offer.”

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MACSEA supplies multibeam sonar for C-Innovation ROV

Tritech’s range of Gemini multibeam imaging sonars are rapidly becoming the sonar operators adopt to navigate, visualise and monitor in poor visibility and turbid warters.

C-Innovation do Brasil recently used the deep-rated Gemini 720i to inspect the hull of an FPSO turret; to inspect a repair and to monitor the surrounding environment.
The inspection was to locate a repair, approximately 40cm wide, on the hull of the FPSO. During the operation, the vehicle was slightly elevated and tilted towards the riser and held at a depth of 15 m away from the hull of the FPSO, due to the vast number of risers and mooring lines; therefore the Gemini sonar was operating at long-range.
C-Innovation operated a Schilling ROV, as fitted with the Gemini 720id and Tritech’s local service partner, MACSEA Ltda provided local customer technical support for the demonstration.

Renan Ocampo, Support Technician, MACSEA commented:
“We developed the Gemini brackets based on Schilling ROV frame, making it adjustable and easy to install, providing a good inspection angle.”

Alex Maia, General Manager, C-Innovation do Brasil commented:
“Our ROV fleet is adaptable to host many plug-and-play technologies, including Tritech’s Gemini. We have made several riser inspections where the Gemini helped quite a lot, especially around the TDP [touch-down point] where there was low visibility, here we could clearly see the trench below the suspension, thanks to the imagery of the Tritech Gemini sonar.”

Tomás Peixoto, ROV Operations Coordinator, C-Innovation do Brasil commented:
“We were amazed by the image quality and the operational performance of the Gemini sonar which enhanced our ability to navigate in low visibility, as well as provide a clear window for target identification during the survey. Overall we completed the job in a safe and timely manner.”