SMaRC Academy Seminars, May 7th 2021

As part of the SMaRC academy, a series of seminars covering the research within SMaRC will be held during spring 2021. The registration for the second event is now open. Welcome to join!

Time & date: May 7th at 13:00-15:15

Joana Fonseca, Tracking and Forecasting of Algal Blooms Using Satellite Ocean Data and USVs
13:30 – 14:00 Therese Tärnholm, Autonomous systems and the implementation of innovative technology
14:00-14:15 Coffee
14:15 – 14:45 Li Ling, AUV localization with sidescan sonar
14:45 – 15:15 Viktor Lidström, Noncoherent Acoustic Underwater Communication

To be able to join the webinar you must register beforehand.

To be able to join the webinar you must register beforehand.

Joana Fonseca

Tracking and Forecasting of Algal Blooms Using Satellite Ocean Data and USVs

Joana FonsecaAbstract: Harmful algal blooms occur frequently and cause human illness, large-scale mortality of fish, shellfish, mammals, and birds, and deteriorates water quality. To control these detrimental effects, accurate information about the location and movement patterns of algal blooms are valuable. An indicator of algal bloom presence is chlorophyll concentration.

We consider the problem of tracking algal blooms front using a USV and satellite data. The USV has a sensor that measures the concentration of chlorophyll. We propose a protocol that allows the USV to find and track algal bloom fronts by least-squares estimation from past chlorophyll measurements. The satellite provides past data from the Baltic sea on chlorophyll, salinity, temperature, and other relevant parameters. We use neural networks to forecast algal bloom spread, given by chlorophyll concentration. Given the algal bloom forecast from the satellite and the local chlorophyll measurements from the USV, we use Gaussian regression to reduce the ocean sampling error.

Current implementation efforts include Matlab simulations, Neptus/Dune numerical experiments, and drone experiments at SML. The next step is sea/ocean implementation using the Neptus/Dune platform.

Therese Tärnholm

Autonomous systems and the implementation of innovative technology

Therese TärnholmAbstract: Autonomous systems are researched, developed, and debated in many different domains, states and entities, the Armed Forces included. The aim for this PhD work is to sharpen the ability within the Swedish Armed Forces in general, the Navy in particular, to understand the technical development of autonomous systems in relation to other research areas.

Three studies will be presented in short. The first one handle issues concerning the concept development of innovative technologies into organisations like armed forces, the second one focus on the ethical and legal aspects of using autonomous underwater systems, especially in a military context. The third study is a case study where different units within the Swedish Armed Forces will be questioned on their participation in capability development when introducing new technology. The presentation will end with two examples from the studies: how the capability perspective could be used in concept development and how rules and ethical aspects can be related to the technological systems.

Li Ling

Noncoherent Acoustic Underwater Communication

Li LingAbstract: In underwater environments, the perception and navigation systems are heavily dependent on the acoustic wave based sonar technology. Sidescan sonar (SSS) provides high-resolution, photo-realistic images of the seafloor at a relatively cheap price. These images could be considered potential candidates for place recognition and navigation of autonomous underwater vehicles (AUVs).
In this talk, I will describe the characteristics of sidescan sonar, the benefits as well as challenges with using sidescan sonar data for AUV localization. Specifically, I will present a deep learning based approach to SSS image correspondence matching, where SSS images from a seafloor area with bottom trawling marks were used.

Lastly, I will briefly touch upon how sidescan data will be used in the upcoming demo at Kristineberg.

Viktor Lidström

Noncoherent Acoustic Underwater Communication

Viktor LidströmAbstract: The underwater domain poses many difficulties for any communicating platform; water attenuates signals that are transmitted using radio, light, and sound. However, the attenuation of sound is highly dependent on frequency, and can be used to communicate over kilometers using a limited bandwidth.  The acoustic channel often has a relatively long and time-varying impulse response, and tracking the phase shift due to the channel is a difficult and energy-costly problem to solve for a coherent method. A noncoherent method does not require phase tracking, and is inherently more robust. This talk will showcase the varietly of underwater channels, and how a noncoherent method deals with them.