Norwegian Defence Research Establishment Research Articles

The Effect of Internal Wave-Related Features on Synthetic Aperture Sonar

In October 2012, the Centre for Maritime Research and Experimentation (CMRE, La Spezia, Italy) conducted trials from the NATO research vessel (RV) Alliance, off Elba Island, Italy. During this trial, data were collected by the Norwegian Defence Research Establishment (FFI, Kjeller, Norway) using a HUGIN autonomous underwater vehicle (AUV) with interferometric synthetic aperture sonar (SAS) in repeated passes. Large linear structures (tens of meters by several meters) observed in both the SAS images and SAS bathymetry during the initial pass were absent in data taken on a repeated pass the following day. We suggest that these phenomena were not true seafloor features, but were caused by features in the water column, known as boluses, which can form after breaking internal wave events. The changes observed in acoustical intensity and phase appear to be caused by the interaction of the acoustical field with the lower average sound-speed structure of the bolus, constructing features in both SAS imagery and SAS bathymetry that looked like seabed topography. In this paper, we present examples and give an interpretation of the results based on an acoustical ray model. We discuss different techniques for recognizing these phenomena: repeat pass imaging and interferometry, multilook and multiaperture processing, and moving target analysis.

Merten, Ulrich. Forgotten Voices: The Expulsion of Germans from Eastern Europe after World War II (review)

SEER, 93, 3, JULY 2015 582 Christopher Browning, Theo Schulte and Omer Bartov should feature Beorn’s volume as well. Norwegian Defence Research Establishment Johannes Due Enstad Merten, Ulrich. Forgotten Voices: The Expulsion of Germans from Eastern Europe after World War II. Transaction, New Brunswick, NJ and London, 2013. xx + 336 pp. Notes. Bibliography. Index. $29.95 (paperback). Studies on the ‘German East’ have reached a curious stage. Since the renewed interest in German victimhood during the late 1990s, research has increasingly emerged that covers a fascinating and apparently inexhaustible field of study. The rediscovery of what some scholars — especially in Germany — labelled a ‘taboo’ has led to an omnipresence of the lost German past in the East, particularly the contentious history and legacy of the expulsions of Germans from East-Central Europe towards the end of and following the Second World War. So far-reaching has this interest become that even unshakable British truths about World War Two and Britain’s relationship with Europe are now up for debate. In the autumn of 2014, the British Museum, along with BBC Radio 4, introduced the British public to ‘forgotten’ German pasts with its programme Germany: Memories of a Nation. The exhibition at the British Museum charted 600 years of German history and began this tour de force with a focus on towns and cities that are no longer part of Germany, among them Königsberg/Kaliningrad, Danzig/Gdańsk and Prague. Despite this outpouring of interest in the German East, the issue of expulsions and German victims of World War Two — an interest that has long extended well beyond the erstwhile parochial Landsmannschaften (homeland societies) — has remained something that scholars feel the need to preface with claims of breaking a taboo (German victims) and covering new ground (the German East). Ulrich Merten’s book, Forgotten Voices, is no exception, as the title itself indicates. A detailed and often quite personal book on the German experiences of expulsion from East-Central Europe during the 1940s, it also claims to tread new ground. Similar to other recent publications — R. M. Douglas’s Orderly and Humane: The Expulsion of the Germans after the Second World War (New Haven, CT, 2012), comes to mind — Merten takes the reader on a country-by-country journey and details the experiences of Germans from Poland, Czechoslovakia, Hungary, Romania and elsewhere through their own voices. What makes this book worthwhile is Merten’s very personal insight into its subject matter. Born in Berlin in 1930 to a bourgeois family that opposed the Nazi regime, Merten and his family left the Third Reich for the USA in the late 1930s. Thereafter, he spent his life as a German exile torn between several worlds: REVIEWS 583 the USA, Nazi Germany and post-war Germany. Having lived in the shadow of the Third Reich in a country that, since the 1970s, has seen a remarkable surge in Holocaust memorialization, it is unsurprising that writing a book on German victims represented a seminal moment for Ulrich Merten’s own biography. This is evident in his preface and repeated protests (perhaps too many?) that he is not attempting to argue that the expulsion of Germans from East-Central Europe was in any way comparable to the Holocaust. Despite its good intentions, however, the book repeats a number of problematic claims regarding the nature of these expulsions. Although Merten points out that the expulsions happened for various reasons, including revenge and settling old scores (pp. 3–4), he repeatedly places the Holocaust and the expulsions in direct relation to each other. This feels like a throwback to older debates of the late 1990s and early 2000s which came close to creating an equivalence between these two events. The book could have been much clearer on the differences of victimhood between the Holocaust and the German expulsions. Both Jews and Germans were placed in camps; both Jews and Germans were put on trains and deported from their homelands. But this is where the similarities end. The majority of German expellees and refugees walked into promising futures in East and West Germany: for expellees in East Germany, the first decades after the war brought the end...

Korostoleva, Elena. The European Union and its Eastern Neighbours: Towards a More Ambitious Partnership? (review)

REVIEWS 391 Another strength of the book is that the oral history interviews allows Cohen to critically assess the relationship between wartime experiences and official post-war memory politics. As Cohen finds, the chaotic and painful realities of life and survival under occupation were not accounted for in the official memory of the post-war years. Perhaps for that reason, the war myth, despite sustained official efforts to institute it, seems to have exerted limited power over the minds of Cohen’s interviewees. The book’s main weakness is the lack of clear, guiding research questions. For instance, we learn that the main thesis of chapter seven (‘Propaganda and Persuasion’) is that ‘all the ‘rational’ or ‘logistical’ energies, resources, and time that went into persuading civilians by word (written or oral) or illustration (poster or motion picture) probably had less of a long-term influence or footprint than the overall emotions that the enduring occupation evoked’ (p. 149). Such vague and convoluted research questions are hardly answerable, and as a result too much of the book reads like a report on the author’s sources. While the sources are often interesting in and of themselves, better research questions would have focused the narrative and added to the book’s argumentative value. While the source base in general appears adequate, it is somewhat curious that the author has not consulted archival holdings in Germany. The reason for the omission is not clear. Not least with regard to popular attitudes and propaganda, military records held in Freiburg could have offered much valuable information. The above objections notwithstanding, Smolensk under the Nazis remains a fascinating account of everyday Soviet life under German rule in Russia which adds substantially to our knowledge of the period. It deserves to be read by scholars and others interested in the Great Patriotic War in general and everyday life under occupation in particular. Norwegian Defence Research Establishment Johannes Due Enstad Korostoleva, Elena. The European Union and its Eastern Neighbours: Towards a More Ambitious Partnership? BASEES/Routledge Series on Russian and East European Studies, 78. Routledge, London and New York, 2012. xix + 188 pp. Map. Figure. Notes. Bibliography. Index. £85.00. Elena Korostolova’s book aims to contribute to scholarly — and policy — debate in two main areas, both of which are well covered in the literature and sound familiar. First, as the title indicates, to explore the nature and difficulties of the EU’s policy towards the eastern neighbourhood, focusing on the EU’s core instruments of engagement — the European Neighbourhood Policy SEER, 93, 2, APRIL 2015 392 (ENP) and its offspring Eastern Partnership (EaP). Second, to draw from this some conclusions about the effectiveness of the EU as an external actor and the familiar discourse of the EU as a ‘transformative power’. Published in 2012, the study is based on field research carried out between 2008 and 2011 in four countries — Belarus, Moldova, Russia and Ukraine. Data was collected via multiple methods including national surveys, focus group discussions, interviews (over 100) and school essays. Thus a key quality and distinct feature is the originality of the underpinning research that provides insights into: the extent to which the wider population in those four countries are informed about the EU and the level of interest in it; how citizens of various ages and backgrounds view the EU itself, the merits of the EU’s policy towards and relations with their country and their country’s policy towards and engagement with the EU. There are seven chapters including the introduction and conclusions. The introduction provides an extremely useful overview of the evolution of the ENP/EaP, highlighting the interventions and competing preferences of actors and institutions within the EU and also reflects on the scholarly literature. Chapters one and two cover the concepts of partnership and the primacy of governance in EU policy respectively. Chapters three, four and five are the country case studies. The contradiction between, and consequences of, the EU’s rhetoric of partnership and the reality of the EU’s actual approach is the central theme. The study emphasizes the EU’s de facto adherence to its longstanding practice of conditionality-based transfer of rules and legislation — that...

Optimization Model for Robust Acquisition Decisions in the Norwegian Armed Forces

The Norwegian Defence Research Establishment (FFI) supports the Norwegian Ministry of Defence with quantitative analyses for its long-term defence planning. As part of this activity, FFI has developed a stochastic model for optimizing investments in materiel. The model maximizes the capabilities of the force structure (i.e., military personnel, equipment, and materiel) by allocating materiel acquisition projects over time, given certain constraints and considering the uncertainty of future-year budgets. The objective of the model is to make decisions about current acquisition projects, and also provide flexibility for future decisions. It models future budgets using a set of budget scenarios. The model helps decision makers explore project acquisition choices, and improve their knowledge of the total investment picture and of individual projects. The model has given FFI new insights into the dynamics of acquisition planning and the necessity for considering future uncertainty.

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HgCdTe Research at FFI: Molecular Beam Epitaxy Growth and Characterization

This paper presents results from recent work on molecular beam epitaxy growth of HgCdTe at the Norwegian Defence Research Establishment (FFI), including studies of material properties and fabrication of photodiodes and nanostructures. Systematic studies of defect morphology in HgTe and Hg1� xCdxTe have revealed that there is a minimum in the area covered by defects just below the onset of Te precipitation. The shape and density of microvoids in HgTe can be used to determine the deviation from the optimal growth temperature. This can be further related to the optimal growth temperature of Hg1� xCdxTe with any Cd mole fraction by thermodynamic calculations. A mechanism for the formation of microvoids and needles has been presented. Photoluminescence (PL) has been used to study layers without doping and with Hg vacancy, Ag, and In doping. Planar photodiodes with high dynamic resistance and good quantum efficiency were fabricated by ion-milling vacancy-doped mid-wave and long-wave infrared layers. Quantum wells (QWs) with good crystallinity and high PL light output have been grown. Surface patterning has been found to enhance light emission from HgCdTe thin-film and QW samples by � 30%. Single-crystal HgTe and segmented HgTe/Te nanowires have been grown, and the resistivity of the nanowires has been measured by conductive atomic force microscopy (AFM), where the AFM tip has been used as a mobile electrode.

Operational Analysis Support to Defence in Norway

Most of the military operational analysis (OA) in Norway takes place at the Norwegian Defence Research Establishment (FFI). FFI was established in 1946 by initiative of scientists that had participated in military research teams in the United Kingdom, during World War II. No Norwegians did, however, participate in operational analysis units in the UK at that time. OA was therefore not carried out at FFI in its earliest days, but a small OA unit—named the Systems Group—was established in the late 50’s.

Teaching & Learning Guide for: Sociology of Terrorism and Counterterrorism: A Social Science Understanding of Terrorist Threat

Over the last decade, increased attention has been paid to terrorism, particularly to the new wave of terrorist groups, fundamentalist movements, and extremist organisations such as Al-Qaeda. September 11 marked the beginning of a turbulent phase in which states face a new kind of threat made up of a complex network of insidious revolutionary and nationalist forces. Such transformations have given rise to an unprecedented number of publications. However, both political violence and terrorism remain sources of endless disputes and controversies because of their political implications. At the same time, in the scientific community, terrorism studies lack conceptual and methodological uniformity. In his article, Domenico Tosini synthesises and discusses some major findings from this research. Courses using such a review will be confronted with the four major topics that any analysis of terrorism, to be comprehensive, should take into account: the definition of terrorism; its history and classification; its explanations; and an assessment of the consequences of counterterrorism policies.

On the occurrence of radioactive fallout over Norway as a result of the Windscale accident, October 1957

A fire at the Windscale plant at Cumbria in the UK between the 10th and the 11th of October 1957 resulted in the first publicised release of radioactivity to the wider environment. The cloud of contamination passed to the southeast of England before travelling northwards on the 14th of October as a result of weather fronts in Europe. Monitoring of radioactive fallout in Norway was at the time conducted by the Norwegian Defence Research Establishment (FFI) using a network of air and precipitation monitoring stations. This article presents results from these monitoring activities which were originally contained in laboratory journals and a series of internal reports produced by FFI. Although mainly classified during the 1950s and 1960s, recent years have seen the incremental declassification of these reports and as the 50th anniversary of the accident approaches, a distillation and reanalysis of this information has been conducted. Results indicate that radioactivity from Windscale was first detected at Bergen and Sola in the south west of Norway and a little later at Værnes, significant amounts of radioactivity being deposited at these locations during the second and third weeks of that month. Results relating to concentrations of activity in air and precipitation and fallout levels are presented for the relevant period and discussed in relation to fallout levels in Norway during the period 1957–1960.

Maritime traffic monitoring using a space-based AIS receiver

The Automatic Identification System (AIS) is a maritime safety and vessel traffic system imposed by the International Maritime Organization (IMO). The system broadcasts position reports and short messages with information about the ship and the voyage. Using frequencies in the maritime VHF band, the coverage is similar to other VHF applications, and is essentially dependent on the altitude of the antenna. For ship-to-ship communications the range is typically 20 nautical miles and for ship-to-shore up to 40 nm. A space-based AIS receiver in low earth orbit will have a range to the horizon of more than 1000 nm, giving an excellent opportunity for large-area ocean surveillance. The Norwegian Defence Research Establishment (FFI) has performed a feasibility study on reception of AIS messages from space. The results show that a ship detection probability of near 100% can be obtained for up to 1000 ships within the coverage area, and that for a standard AIS receiver a signal power margin of 10–20 dB can be achieved. On this background, swath-width analyses for European scenarios are done. It is argued that space-based reception of AIS messages is a promising way of achieving long-range identification and tracking services at marginal cost.

Estimates of Geoacoustic Model Parameters From Inversions of Horizontal and Vertical Line Array Data

This paper describes results from geoacoustic inversion of low-frequency acoustic data recorded at a receiving array divided into two sections, a sparse bottom laid horizontal array (HLA) and a vertical array (VLA) deployed in shallow water. The data are from an experiment conducted by the Norwegian Defence Research Establishment (FFI) in the Barents Sea, using broadband explosives (shot) sources. A two-layer range-independent geoacoustic model, consistent with seismic profiles from the area, described the environment. Inversion for geoacoustic model parameters was carried out using a fast implementation of the hybrid adaptive simplex simulated annealing (ASSA) inversion algorithm, with replica fields computed by the ORCA normal mode code. Low-frequency (40-128 Hz) data from six shot sources at ranges 3-9 km from the array were considered. Estimates of sediment and substrate p-wave velocities and sediment thickness were found to be consistent between independent inversions of data from the two sections of the array

Determination of organoarsenic warfare agents in sediment samples from Skagerrak by gas chromatography-mass spectrometry

In 1945 the Norwegian authorities gave permission to scuttle ships loaded with captured chemical ammunition on board in an area approximately 14 × 4 km in size, 25 nautical miles south-east of Arendal. An investigation was carried out in 2002 to inspect four wrecks by using a remote-operated vehicle with video cameras. The Norwegian Defence Research Establishment (Forsvarets forskningsinstitutt, FFI) carried out the project on behalf of the Norwegian Pollution Control Authority (SFT). Sediment samples were collected at eight positions around each wreck. One of the wrecks was broken up into several smaller parts. Here sediments were collected at one additional position close to one of the parts. From each position, at least two sediment cores were taken up to the surface. One of the cores from each position was sliced into three parts that were immediately frozen. The other whole cores were frozen on board the ship and transported back to the laboratory in a freezer. In total, sediment samples from 33 different locations were collected and analysed for organoarsenic warfare agents and some of their decomposition products by gas chromatography-mass spectrometry (GC-MS) after derivatisation with 1-propanethiol. Most of the identified organoarsenic compounds found in the sediment samples are parts of the arsine oil mixture produced by Germany during World War II. The compounds were found both close to the wreck and at a somewhat longer distance from the wrecks. The highest concentrations were found in a sediment sample collected close to a bomb seen on the seabed. The organoarsenic warfare agents adamsite or lewisite were not found in any of the samples. Lewisite is not reported to have been produced during World War II, but was nevertheless looked for in the samples.

ERS tandem InSAR processing for DEM generation, glacier motion estimation and coherence analysis on Svalbard

This paper describes the unique InSAR (Interferometric Synthetic Aperture Radar) processing algorithms at Norwegian Defence Research Establishment (FFI) and how ERS (European Remote Sensing Satellite) tandem data are used to prove the high performance of the processing chain. The InSAR baselines are estimated from the high precision orbit data only, without using ground control points in the Svalbard test area. The flattening of the interferograms is of high quality and the interferograms are used to generate InSAR DEM (Digital Elevation Model) by using an existing DEM from Svalbard. The root mean square (rms) of the InSAR DEM is between 10 and 20 m in the selected test area. Although one day interferograms with removed terrain fringes were used, a combination of field measurements, photogrammetric methods and interferometry are necessary to obtain a complete pattern of ice velocities on a fast‐moving glacier like Kronebreen (maximum 2 m day−1), where parts of the glacier are heavily crevassed. The study also demonstrated that considerable decorrelation may occur during one day over snow and glaciers due to changing weather conditions.

Multi-level arc combination with stochastic parameters

The method of square root information filtering and smoothing (SRIF/S) is reviewed and has been implemented in the combined square root information filter and smoother (CSRIFS) program. CSRIFS is a part of the GEOSAT space geodesy software developed at Forsvarets forskningsinstitutt (FFI, The Norwegian Defence Research Establishment). The state vectors and complete variance–covariance matrices from the analyses of a number of independent arcs of space geodesy data can be combined using CSRIFS. Four parameter levels are available and any parameter can, at each level, be represented as either a constant or a stochastic parameter (white noise, colored noise, or random walk). The batch length (i.e. the time interval between the addition of noise to the SRIF array) can be made time and parameter dependent. CSRIFS was applied in the combination of 623 very long baseline interferometry (VLBI) observing sessions. The purpose of this test was to validate the computer implementation of the SRIF/S method and to give an example of how this method can be used in the analysis of a large number of space geodetic observations. The results show that the implementation is very satisfactory.

Autonomous Underwater Vehicle for Mine Reconnaissance

An autonomous underwater vehicle for mine reconnaissance is currently being developed by the Norwegian Defence Research Establishment. The system will detect and accurately locate mine-like objects through a systematic, autonomous survey of an area of interest. Multibeam echo sounder data from various dummy mine objects have been collected during several sea trials with HUGIN and other platforms. These real sensor data have been used for evaluation of sensor performance and for developing algorithms for automatic object enhancement and detection. The mine reconnaissance concept will be demonstrated early 2001 with a HUGIN vehicle carrying a minimal mine detection sensor configuration consisting of a side-scan sonar and a multibeam echo sounder. The sensor suite, together with the level of adaptive behaviour, will be upgraded in later versions.

The alkaline aluminium/hydrogen peroxide power source in the Hugin II unmanned underwater vehicle

In 1993, The Norwegian Defence Research Establishment (FFI) demonstrated AUV-Demo, an unmanned (untethered) underwater vehicle (UUV), powered by a magnesium/dissolved oxygen seawater battery (SWB). This technology showed that an underwater range of at least 1000 nautical miles at a speed of 4 knots was possible, but also that the maximum hotel load this battery system could support was very limited. Most applications for UUV technology need more power over a shorter period of time. Seabed mapping using a multibeam echo sounder mounted on an UUV was identified as a viable application and the Hugin project was started in 1995 in cooperation with Norwegian industry. For this application, an endurance of 36 h at 4 knots was required. Development of the UUV hull and electronics system resulted in the UUV Hugin I. It carries a Ni/Cd battery of 3 kW h, allowing up to 6 h under-water endurance. In parallel, we developed a battery based on a combination of alkaline Al/air and SWB technology, using a circulating alkaline electrolyte, aluminium anodes and maintaining the oxidant concentration in the electrolyte by continuously adding hydrogen peroxide (HP) to the electrolyte. This concept resulted in a safe battery, working at ambient pressure (balanced) and with sufficient power and energy density to allow the UUV Hugin II to make a number of successive dives, each of up to 36 h duration and with only 1 h deck time between dives for HP refill and electrolyte exchange. After 100 h, an exchange of anodes takes place. The power source consists of a four-cell Al/HP battery, a DC/DC converter delivering 600 W at 30 V, circulation and dosing pumps and a battery control unit. Hugin II is now in routine use by the Norwegian Underwater Intervention AS (NUI) which operates the UUV for high-precision seabed mapping down to a water depth of 600 m.

Precise ERS-2 orbit determination using SLR, PRARE, and RA observations

The second European Remote Sensing satellite ERS-2, launched in 1995, is supported by satellite laser ranging (SLR), the German precise range and range-rate equipment (PRARE) microwave tracking system, and radar altimetry (RA). SLR, PRARE and crossover RA observations (XO/RA) from May, June, and July 1996 have been analyzed using the GEOSAT software developed at Forsvarets forskningsinstitutt (FFI, The Norwegian defence research establishment). Orbits computed with the JGM3 gravity model and the more recent EGM96 gravity model have been compared with orbits from other analysis centers. Based on these comparisons in addition to the post-fit observation residuals, and results from internal orbital overlaps, we conclude that the radial component of the ERS-2 orbit can be determined with a precision of 6 cm.

The control system of an autonomous underwater vehicle

This paper presents the flight control system of an Autonomous Underwater Vehicle (AUV) developed at the Norwegian Defence Research Establishment. A mathematical model of the vehicle is derived and discussed. The system is separated into lightly interacting subsystems and three autopilots are designed for steering, diving and speed control. The design of the separate controllers is based on PID techniques. Results from sea trials show robust performance and stability for the autopilot

Circadian rhythm of hormones is extinguished during prolonged physical stress, sleep and energy deficiency in young men

The circadian rhythm of hormones (N = 10) and mental performance (N = 18) was investigated in male cadets during a 5-day military training course with continuous heavy physical activities corresponding to 35% of the maximal oxygen uptake, with almost total lack of food and sleep. The 24-h means for androstenedione, dihydroepiandrosterone (DHEA), 17 alpha-hydroxyprogesterone, testosterone and thyroid-stimulating hormone decreased strongly during the course, and the circadian rhythm was extinguished below the minimum levels measured during the control experiment. The 24-h means for cortisol, dihydroepiandrosterone sulfate (DHEA-S) and progesterone increased during the course, and the circadian rhythm was abolished above the maximum levels of the control experiment. A gradual increase was found in thyroxine, free thyroxine and triiodothyronine during the first 12 h of activities, followed by a constant decrease for the rest of the course. Mental performance decreased during the course and the amplitude of its circadian rhythm increased from +/- 10% to +/- 30% of the 24-h mean. The circadian rhythms investigated were almost normalized after 4-5 days of rest. However, the nocturnal rise for cortisol, androstenedione and DHEA appeared earlier, and the plasma levels of thyroid hormones, estradiol and DHEA-S were lower during the recovery experiment than in the control experiment. The responses to stress of the circadian rhythm for mental performance and steroid hormones during the course indicate a differential regulation.

The NDRE-AUV flight control system

The flight control system of an autonomous underwater vehicle (AUV) developed at the Norwegian Defence Research Establishment (NDRE) is presented. A mathematical model of the vehicle is derived and discussed. The system is separated into lightly interacting subsystems, and three autopilots are designed for steering, diving, and speed control. The design of the separate controllers is based on PID techniques. Results from extensive sea testing show robust performance and stability for the autopilot. >