Maritime Moving Target Detection, Tracking and Geocoding Using Range-Compressed Airborne Radar Data

Eine regelmäßige und großflächige überwachung des Schiffsverkehrs gewinnt zunehmend an Bedeutung, vor allem auch um maritime Gefahrenlagen und illegale Aktivitäten rechtzeitig zu erkennen. Heutzutage werden dafür überwiegend das automatische Identifikationssystem (AIS) und stationäre Radarstationen an den Küsten eingesetzt. Luft- und weltraumgestützte Radarsensoren, die unabhängig vom Wetter und Tageslicht Daten liefern, können die vorgenannten Systeme sehr gut ergänzen. So können sie beispielsweise Schiffe detektieren, die nicht mit AIS-Transpondern ausgestattet sind oder die sich außerhalb der Reichweite der stationären AIS- und Radarstationen befinden. Luftgestützte Radarsensoren ermöglichen eine quasi-kontinuierliche Beobachtung von räumlich begrenzten Gebieten. Im Gegensatz dazu bieten weltraumgestützte Radare eine große räumliche Abdeckung, haben aber den Nachteil einer geringeren temporalen Abdeckung. In dieser Dissertation wird ein umfassendes Konzept für die Verarbeitung von Radardaten für die Schiffsverkehr-überwachung mit luftgestützten Radarsensoren vorgestellt. Die Hauptkomponenten dieses Konzepts sind die Detektion, das Tracking, die Geokodierung, die Bildgebung und die Fusion mit AIS-Daten. Im Rahmen der Dissertation wurden neuartige Algorithmen für die ersten drei Komponenten entwickelt. Die Algorithmen sind so aufgebaut, dass sie sich prinzipiell für zukünftige Echtzeitanwendungen eignen, die eine Verarbeitung an Bord der Radarplattform erfordern. Darüber hinaus eignen sich die Algorithmen auch für beliebige, nicht-lineare Flugpfade der Radarplattform. Sie sind auch robust gegenüber Lagewinkeländerungen, die während der Datenerfassung aufgrund von Luftturbulenzen jederzeit auftreten können. Die für die Untersuchungen verwendeten Daten sind ausschließlich entfernungskomprimierte Radardaten. Da das Signal-Rausch-Verhältnis von Flugzeugradar-Daten im Allgemeinen sehr hoch ist, benötigen die neuentwickelten Algorithmen keine vollständig fokussierten Radarbilder. Dies reduziert die Gesamtverarbeitungszeit erheblich und ebnet den Weg für zukünftige Echtzeitanwendungen. Der entwickelte neuartige Schiffsdetektor arbeitet direkt im Entfernungs-Doppler-Bereich mit sehr kurzen kohärenten Verarbeitungsintervallen (CPIs) der entfernungskomprimierten Radardaten. Aufgrund der sehr kurzen CPIs werden die detektierten Ziele im Dopplerbereich fokussiert abgebildet. Wenn sich die Schiffe zusätzlich mit einer bestimmten Radialgeschwindigkeit bewegen, werden ihre Signale aus dem Clutter-Bereich hinausgeschoben. Dies erhöht das Verhältnis von Signal- zu Clutter-Energie und verbessert somit die Detektierbarkeit. Die Genauigkeit der Detektion hängt stark von der Qualität der von der Meeresoberfläche rückgestreuten Radardaten ab, die für die Schätzung der Clutter-Statistik verwendet werden. Diese wird benötigt, um einen Detektions-Schwellenwert für eine konstante Fehlalarmrate (CFAR) abzuleiten und die Anzahl der Fehlalarme niedrig zu halten. Daher umfasst der vorgeschlagene Detektor auch eine neuartige Methode zur automatischen Extraktion von Trainingsdaten für die Statistikschätzung sowie geeignete Ozean-Clutter-Modelle. Da es sich bei Schiffen um ausgedehnte Ziele handelt, die in hochauflösenden Radardaten mehr als eine Auflösungszelle belegen, werden nach der Detektion mehrere von einem Ziel stammende Pixel zu einem physischen Objekten zusammengefasst, das dann in aufeinanderfolgenden CPIs mit Hilfe eines Bewegungsmodells und eines neuen Mehrzielverfolgungs-Algorithmus (Multi-Target Tracking) getrackt wird. Während des Trackings werden falsche Zielspuren und Geisterzielspuren automatisch erkannt und durch ein leistungsfähiges datenbankbasiertes Track-Management-System terminiert. Die Zielspuren im Entfernungs-Doppler-Bereich werden geokodiert bzw. auf den Boden projiziert, nachdem die Einfallswinkel (DOA) aller Track-Punkte geschätzt wurden. Es werden verschiedene Methoden zur Schätzung der DOA-Winkel für ausgedehnte Ziele vorgeschlagen und anhand von echten Radardaten, die Signale von echten Schiffen beinhalten, bewertet

Why synthesize new elements

In September 2009, a team of scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory confirmed a claim made by a team of Russian scientists at the Joint Institute for Nuclear Research in Dubna in 1998 — it was possible to create element 114. The Russian team (led by Yuri Oganessian) had described element 114, now called flevorium, as being “very stable”. Today, however, this element does not exist

The saga of atomic weights

Who were the first people to think of the concept of atomic weights? How were atomic weights of elements first calculated? In this article, the authors explore the long scientific journey from the origins of the widely used conceptual framework of atomic weights to the debates on the topic prevalent even today

Confer ment ence on International Agricultural Research for Develop Effects of Farmers' Perceptions on the Adoption of Modern Rice Varieties in Nepal

Abstract everal modern varieties of rice have been released in Nepal to raise the productivity, a major pies about 50 percent of the total area under food S staple crop. Farmers have adopted these varieties to varying degrees, especially in rainfed areas. This paper attempts to identify factors that affect the adoption of modern varieties of rice. Farmers considered suitability of rice varieties based on several characteristics. They were more concerned with biotic and abiotic stresses, which probably reflects the high incidence of these stresses in the rainfed condition. Modern varieties were superior over traditional varieties for many characteristics except in terms of taste. It is hypothesized that farmers' perceptions regarding varietal characteristics play a key role in explaining adoption behavior. This hypothesis was tested using farm-level data from rainfed areas of Nepal. An econometric model that includes farmers' perception variables was found to be superior in explaining adoption behavior than the ones that include only the usual farm and farmer related variables. Farmers' perceptions of the varietal characteristics such as pest resistance, drought tolerance and suitability for making special products were important in determining technology choices in the areas where current adoption rates are quite high. It was also found that the farms and farmers' specific variables such as education of the decision maker and his/her experience in rice farming, and availability of extension services have significant effect on adoption of modern varieties. Research approaches that incorporate farmers' preferences for various characteristics of rice in breeding programs and extension strategies that are geared towards providing accurate information for efficient revision of farmer perceptions are needed to raise the adoption rate. Background and Aim of the Study Rice is the staple food crop of Nepal. It occu crops of 3.2 million hectares and its contribution to the total food supply is more than 50 percent. This crop alone contributes to about 40 percent of the total calorie intake. In order to increase the productivity, modern varieties (MVs) of rice were introduced in late 1960s in Nepal. Overall, the spread of MVs and associated technologies is concentrated in pockets of favorable irrigated areas, with farmers choosing to follow largely traditional practices in less favorable rainfed areas. Although over 48 MVs have been released in Nepal, limited spread of MVs and their low productivity continue to remain major constraints to increasing the rice production in Nepal. Analysis of factors constraining the diffusion of MVs, especially in the dominant rainfed ecosystem of Nepal, is hence, an important area of research

Influence of defect pairs in Ga-based ordered defect compounds: a hybrid density functional study

In the present paper, density functional theory (DFT) based calculations have been performed to predict the stability, electronic, and optical properties of Ga-rich ordered defect compounds (ODCs). The calculated lattice constants, bulk modulus, their pressure derivatives, and optical constants show good agreement with available experimental data. The hybrid exchange correlations functional have been considered to calculate ground state total energy and energy band gap of the material. The calculated formation energy of ODCs comes smaller than pure CuGaSe2 (CGS). Our calculated optical absorption coefficients indicate that the energy band gap of ODCs can be tuned by changing the number of donor-acceptor defect pairs (2V(cu)(-), + Ga-cu(2+)). The band offset has been calculated to understand the reason of band gap alteration while the number of defect pair changes. Our results may be helpful for other experiments to further improve the performance of ODCs

Sequential Damming Induced Winter Season Flash Flood in Uttarakhand Province of India

204 persons were killed while two hydropower projects located in close proximity at Rishiganga (13.2 MW), and Tapoban (520 MW) were damaged in Dhauliganga flood of February 7, 2021 in the Indian Himalaya. This incidence occurred during the winter season when the discharge of the glacier fed rivers is minimal, and no rain was experienced in the region around the time of the flood. Despite discharge of the main river, Rishiganga, not involved in the flood due to damming upstream of its confluence with Raunthi Gadhera, based on field evidences massive volume of around 6 million cu m water involved in this flood is attributed to sequential intermittent damming at three different places; (i) Raunthi Gadhera was dammed first in its upper reaches, (ii) Rishiganga river was then dammed to the north of Murunna, and (iii) finally Dhauliganga river was dammed around Rini village to the upstream of its confluence with Rishiganga river. Lacking warning system only enhanced the flood-induced devastation. Legally binding disaster risk assessment regime, together with robust warning generation, and dissemination infrastructure are therefore recommended for all major infrastructure projects

Altered Mucins (MUC) trafficking in benign and malignant conditions.

Mucins are high molecular weight O-glycoproteins that are predominantly expressed at the apical surface of epithelial cells and have wide range of functions. The functional diversity is attributed to their structure that comprises of a peptide chain with unique domains and multiple carbohydrate moieties added during posttranslational modifications. Tumor cells aberrantly overexpress mucins, and thereby promote proliferation, differentiation, motility, invasion and metastasis. Along with their aberrant expression, accumulating evidence suggest the critical role of altered subcellular localization of mucins under pathological conditions due to altered endocytic processes. The mislocalization of mucins and their interactions result in change in the density and activity of important cell membrane proteins (like, receptor tyrosine kinases) to facilitate various signaling, which help cancer cells to proliferate, survive and progress to more aggressive phenotype. In this review article, we summarize studies on mucins trafficking and provide a perspective on its importance to pathological conditions and to answer critical questions including its use for therapeutic interventions

Effect of foliar spray of ethephon doses and pruning intensities on growth, sex expression, and yield of cucumber (var- Bhaktapur local) in Kaski, Nepal

A field experiment was conducted to study the effect of foliar spray of ethephon doses and pruning intensities on the performance of Bhaktapur local cultivar of cucumber in Kaski, Nepal from Feb- May 2021. The study was laid out in Randomized Complete Block design (RCBD) with 2G and 3G cutting, and four different doses of ethephon (@125ppm, @250ppm, @375ppm @500ppm) as six treatments against control and were replicated four times with 28 plots each of 20.8 m2 size having 4 rows with 4 plants per row. The data regarding plant height, leaf number, largest leaf area, days to 1st male and female flowering and fruit harvest, the total number of male and female flowers per plant, M: F flower ratio, fruit length, circumference, weight/fruit, fruit number per plant, fruit set % and yield were recorded and analyzed using MS-Excel and R-studio. The result revealed that growth and yield were significantly influenced by the levels of ethephon and pruning. Highest yield was recorded with ethephon @125ppm (83.54 t ha-1) which is as par with 3G (72.57 t ha-1) which was accompanied by a significantly higher number of fruits per plant {(125ppm=18.33), (3G=15.67)}, average fruit weight {(3G=674gm)}, (125ppm=608gm)}, and fruit set % {(3G=30.66 %)}, (125ppm=24.93 %)}. Significantly higher plant height (149.78 cm), and the highest number of leaves per plant (40) were recorded in control and Ethephon @125ppm at 50 DAT, respectively. The largest leaf area (626.84 cm2) was recorded in 2G which is at par with 3G (613.31 cm2) at 50 DAT. Higher dose of ethephon @500ppm (47.87 days) and 375 ppm (47.17 days) delayed days to 1st male flowering while all ethephon doses (T4=31.83 days, T5=32.5 days, T6=34.81 days, and T7=34.83 days) hastened female flowering than control and pruning. A significantly higher number of male flowers were obtained in the control (89.75), while the number of female flowers and M: F flower ratio increased with increasing ethephon level than in pruning (2G and 3G) and control. Hence, appropriate ethephon (125ppm) dose and pruning (3G) were highly conducive for better growth, sex expression, and yield of cucumber using Bhaktapur Local variety of cucumber in the hilly region of Nepal has a climatic condition similar to Kaski

Geostatistical based soil fertility mapping of Horticultural Research Station, Rajikot, Jumla, Nepal

Geostatistical soil mapping is important for determining spatial distribution of soil parameters. This study was conducted to assess soil spatial distribution of the Horticultural Research Station, Rajikot, Jumla, Nepal. The total 27 samples were collected randomly at a depth of 0-20 cm by using soil sampling auger. A GPS device was used for determination of geographical position of soil sampling points. The collected samples were analyzed following standard analytical methods in the laboratory of National Soil Science Research Centre, Khumaltar. The Arc-GIS 10.1 software was used for the mapping spatial distribution of various soil parameters. The observed data revealed the structure was sub-angular blocky and granular, whereas colour were dark brown to dark grayish brown and dark yellowish brown. The sand, silt and clay content were ranged 24.40-72.10%, 19.40-63.10% and 6.20-14.50%, respectively and categorized loam, sandy loam and silt loam in texture. The soil pH was slightly acidic to moderately alkaline (5.01-8.06), and very low available sulphur (0.59-2.41 mg/kg) and very low to low available boron (0.04-0.87 mg/kg).  Moreover, very low to medium available manganese (2.18-13.46 mg/kg), very low to very high available iron (4.50-138.58 mg/kg), and low to medium available magnesium (7.20-177.60.53 mg/kg) and zinc (0.26-1.66 mg/kg). Similarly, medium total nitrogen (0.09-0.22%), medium to high organic matter (1.71-6.26%) and available calcium (1200-3144 mg/kg), medium to very high available phosphorus (3.71-82.4 mg/kg) and potassium (59.37-173.05 mg/kg). Correspondingly, high to very high available copper (0.78-4.20 mg/kg). The determined soil test data can be used for sustainable soil management as well as developing future research strategy in the farm