Report that covers interim results during the course of a project. Note: Unless linked to the full text, reports are only available to NATO member nations from designated distribution centres.
ISR Implementation of ocean optics protocols to estimate spectral absorption coefficients of particles, suspended matters and phytoplankton pigments in ALOMEx'15 water samples: results and comparisons with satellite measurements
ISR Implementation of ocean optics protocols to estimate spectral absorption coefficients of particles, suspended matters and phytoplankton pigments in ALOMEx'15 water samples: results and comparisons with satellite measurements. Pennucci, Giuliana; Sanjuan Calzado, Violeta. CMRE-MR-2016-021. March 2017.
One of the main requirements for a comprehensive characterisation of water column optical properties is the simultaneous acquisition of physical and biological parameters that are traditionally observed using satellites, laser systems, ships and moorings, especially in dynamic areas. The Atlantic Lidar Optical Measurements Experiment 2015 (ALOMEx'15), conducted from 31 October to 12 November 2015 the Alboran Sea and Sahara Upwelling, provided an attempt at determining in situ measurement uncertainties by comparing instrument specific calibrations and measurement protocols. In this context, two different topics have been addressed in this report: (1) post- processing algorithms development to analyse optical water column properties and (2) data comparison and validation using satellite imagery. Specifically, introduction and conventions are provided in the first part of this document (Sections 1 and 2), while the post-processing algorithms which were implemented at CMRE to analyse bio-optical and radiometric measurements performed simultaneously with the Lidar system and optical satellite data (i.e. from the Moderate Resolution Imaging Spectroradiometer, MODIS, and the Visible Infrared Imaging Radiometer Suite, VIIRS) are described in Section 3. The dataset retrieved from the available in situ water samples (Section 4) is successively used to investigate the ubiquity of optical linkages between the ocean and atmosphere at the global scale using data acquired during a Saharan dust phenomenon that occurred during the cruise. We analysed match-ups comparison between coincident (+/- 1hour) in situ and satellite retrievals, as well as historical satellite measurements to investigate the seasonal variability (Section 5). Results corroborate the hypothesis that the biasing of satellite chlorophyll-a retrievals are correlated with high deposited dust concentrations and may help climatologists to understand the impact of aerosols on correction for satellite ocean data, leading to better ocean colour products (e.g. atmospheric correction and ocean colour algorithms), especially in the presence of dust or other anthropogenic pollutants comparing.
Olives Noires 2016: experimental description and preliminary results. Dugelay, Samantha; Reardon, Eric; Furfaro, Thomas C.; Pailhas, Yan; Carreras, Marc. CMRE-MR-2017-001. February 2017.
This document provides an overview of the Olives Noires Mine Countermeasures Experiment 2016 (ONMEX'16) sea trial held from 15 to 28 September 2016 (including transit), in the Bay of Hyères, France. This trial was in support of the Autonomous Naval Mine Countermeasures (ANMCM) Programme. It describes the operational environment, the experiments conducted as well as the data collected.
Overall, ONMEX'16 was a very successful sea trial. The key achievements were:
- Deployment of the MUSCLE system in a blind Percentage Clearance trial (PC Trial) and overall high performance of the autonomy engine and good detection and classification rates.
- Extensive data collection to support the CMRE Autonomous Mine Search project for:
- Automatic target recognition
- Advanced autonomy concepts on-board MUSCLE
- Advanced autonomy concepts on-board REMUS 100
- In situ planning and evaluation
- International collaboration: University of Girona (ESP), Heriot-Watt University (GBR).
A look into current standardisation gaps in underwater networks. Alves, João; Pelekanalis, Konstantinos; Petroccia, Roberto. CMRE-MR-2016-016. December 2016.
This report highlights some of the key missing elements preventing underwater communications interoperability. The requirement for interoperability and standards is motivated by NATO's multi-national nature where commonalities and joint operations should be explored when possible. To establish interoperable underwater networks, a myriad of challenges must be tackled. These start on establishing common channel models and metrics, continuing all the way into defining standardised networking protocols and security policies. JANUS is introduced as an example of a standardisation effort. This document proposes extensions to the current specification looking at future revisions of the standard.
Multitarget tracking using passive acoustic arrays. Meyer, Florian; Tesei, Alessandra. CMRE-MR-2016-020. December 2016.
This report addresses the problem of localising and tracking an unknown number of targets with unknown acoustic transmit signals from Time-Difference Of Arrival (TDOA) measurements acquired by hydrophone pairs. Based on the framework of random finite sets and finite set statistics, we formulate a Bayesian estimation problem and develop a particle-based detection, localisation, and tracking algorithm that is an extension and adaptation of the Track-Oriented marginal Multi- Bernoulli/Poisson (TOMB/P) filter [1, 2]. The proposed method overcomes the challenges related to the highly non-linear TDOA measurement model, the data association uncertainty, and the uncertainty in the number of targets to be localised and tracked. We evaluate the proposed method by means of simulations and by using measurement data acquired during an experiment performed within the PERSEUS project, where a compact hydrophone array was used as a payload on a covert long-endurance Autonomous Vehicles (AV). Our numerical results confirm that the algorithm is able to determine the number of targets correctly and that it can provide accurate location estimates for static and dynamic targets and in 2D and 3D scenarios when the number of clutter measurements is moderate and the probability of detection is high. In a 2D tracking scenario, where the PERSEUS array is under water and the targets are surface vessels, the localisation accuracy in range, i.e., distance from the array, critically depends on the array depth and the distance of the target. In the fully 3D scenario, at least two PERSEUS arrays are needed for accurate target localisation. These limitations are due both to physical constrains such as the limited bandwidth of the acoustic signals and the compact size of the array and are not related to the proposed algorithm.
Report of the Third CMRE Workshop on Military Applications of Underwater Glider Technology. Borrione, Ines. CMRE-MR-2016-018. December 2016.
During the "Third CMRE Workshop on Military Applications of Underwater Glider Technology ", 26 talks were given to provide an overview of the current industrial, research and military lines of glider research and development. Three presentations were given by representatives of three of the main glider manufacturers (the French company ACSA-Alcen, the American Teledyne Webb Research and the international Kongsberg company, which is based in Norway). These have described the current abilities and applications of their gliders, providing an overview of their strengths during military applications. Engineers and scientists from international military and research centers, have provided an overview of their in-house support systems for glider operations (i.e., pre- and post-deployment, mission planning, data validation and processing) and have given examples of recent experiments involving the deployment of a single glider or a fleet of gliders with innovative payloads and sensors (i.e., reactive behaviour, acoustic payloads). Data end-users from the modeling community have introduced data assimilation techniques that are being developed to exploit the highly dense oceanographic data collected during glider operations.