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183 Uppsatser om Laser radar - Sida 1 av 13

LPI-radar. Nys eller nytta? : Studie av den militära nyttan med LPI-radar.

Sedan radar började användas under första hälften av 1900-talet har duellen mellan radar och signalspaning pågått. Genom att utnyttja radar har alltid en medveten risk tagits, risken att bli upptäckt av motståndarens signalspaning. Duellen gavs möjlighet att ta en paus då radarsystem med låg uteffekt introducerades på marknaden under slutet av 1980-talet, nu fanns plötsligt en möjlighet att använda radar samtidigt som de samtida signalspaningssystemen inte kunde upptäcka dessa radarsystem. I föreliggande magisteruppsats i krigsvetenskap med militärteknisk inriktning undersöks räckviddsförhållanden mellan dessa radarsystem och signalspaningssystem. Genom scenarier i den marina arenan försöker jag värdera de taktiska vinster en användare av radar med låg uteffekt kan göra.

Framkomlighetsanalys med hjälp av en digital terrängmodell och kartdata

Driveability analysis of terrain data offers an important technique for decision support for all kinds of movements in the terrain. The work described in this report uses a high resolution digital terrain model generated from the Laser radar data and further processed by the Category Viewer program, and information from the Real Estate Map. Properties of features found in a filtering process are calculated and compared with a set of rules in a knowledge base to get a driveability cost. This cost is then visualized in a graphical user interface. An evaluation of what driveability is and what it is affected by is performed, and a general cost function is developed, which can be used even if not all relevant information is available.

AIS vs. Radar : En undersökning om aktiva befäls åsikter och uppfattning berörande AIS och radar

Arbetet är en fallstudie om aktiva nautikers inställning till användandet av AIS och radar ur en navigatorisk synpunkt. Syftet var att få en uppfattning om hur ett av de nyaste elektroniska hjälpmedlen står sig mot ett av de mer inarbetade och beprövade instrumenten som finns ombord på dagens kommersiella fartyg.För att kunna få en uppfattning om vad nautikerna ansåg utfördes intervjuer ombord på ett svenskt fartyg. Frågorna som ställdes var samma för både AIS och radar för att datan skulle bli jämförbara. De slutsatser som drogs var att AIS som fristående system inte ännu är något som dagens nautiker litar på. Då radarn togs upp till diskussion var mönstret tydligt att systemet ansågs ha hög tillförlitlighet samt att nautikerna näst efter sina egna ögon litar mest på radarn bland de navigatoriska hjälpmedlen.

FMCW-radar för mätning och beräkning av målbana

I detta arbete studeras möjligheterna att använda s.k. "Frequency-Modulated Continuous Wave radar" (FMCW-radar) för att mäta avstånd och radiell hastighet till ett mål. Vidare undersöks möjligheten att använda en följd av sådana mätdata för att skatta banparametrar för ett mål. Vi utför en två-dimensionell Fouriertransform på radardata. Genom att söka upp maximala värdet av transformerade datas absolutvärden erhåller vi en grov skattning av avstånd och radiell hastighet.

MPD-vågformer för helikopterradar

A helicopter based system equipped with a millimetre-wave fire control radar is studied for improvement of the detection probability for moving ground targets. The system is a pulse doppler radar that sends out the electromagnetic wave in repetitive pulses. The frequency in which radar sends this pulse is called Pulse Repetition Frequency (PRF). The velocity of the moving targets is measured by spectral analysis of the pulses received. With this sort of system some targets will not be possible to detect.

Förtolkning inför skogsbruksplanläggning med laserdata (NNH), eller traditionell flygbildstolkning?

The purpose of this study was to investigate produced laser data from the new national height model's airborne laser scanning in Sweden, what quality it has and whether it can be used for forest management planning. From airborne laser scanning one can obtain information on forest variables such as tree species, height, diameter and basal area. Norra skogsägarna is the principal employer of this project and they wanted know to the quality of the laser data which needs to cope with their standards. If the laser data the quality required it can replace some of the operations performed by field planners. To examine the quality of the produced laser data a control tax assessment has been performed in 30 forest departments. This was done in an objective manner.

Filterdesign och hårdvarukonstruktion för FMCW-radar

Den här högskoleavhandlingen beskriver designen av ett IF-filter samt hårdvarukonstruktion av en ny 77 GHz FMCW-radar demonstrator. Syftet med demonstratorn är att illustrera hur kisel germanium-, SiGe, teknologi kan användas istället för den mer vedertagna men dyrare gallium arsenik-, GaAs, teknologin. Den gamla radar-prototypen vilken Acreo AB utvecklat är funktionell men behöver konstrueras om för att bättre kunna utvärdera radarprestandan. I avhandlingen presenteras grundläggande radarteori och ekvationer för att underlätta förståelsen av de olika systemblocken. Rapporten beskriver också systemarkitekturen och hur dess funktionalitet kommer att testas.

Samband mellan laserdata och fältdata

To make it easier for forestry planning the forest owners needs data which describe characteristics of the forest. Such data you usually get from some type of inventory. A relatively new technology which probably is getting more important in the future, is laser scanning because of lower costs. But because the laser technology is relatively new you need to compare it with conventional inventory technologies to get better understanding of the possibilities the laser technology gives. This work intends to estimate field measured characteristics of the forest from laser data with help of regression analysis and then see which of the field measured properties that best could be estimated and which laser variables that gave the best results. This study shows that heights has the best estimates, but biomass, diameter and volume also gives good estimates.

En oscillatorbank till en lågfrekvensradar : LORA/VHF

The goal of this thesis work is to enable an existing UHF radar to operate in the VHF band instead. In order to achieve this, new coherent local oscillators are required. Different options are suggested and one of them is implemented and analyzed..

Förstudie för automatisering av manuell lödning

This degree project has been carried out in cooperation with Enertech AB in Ljungby and is pilot study to automating all current manual soldering. The soldering process accounts for a large part of the processing cost in the production of a heat pump. The process is also a quality risk and has a major impact on the lifetime of the final product.The Main task of this project has been to evaluate automation of the soldering process, to develop automation solutions and a principle layout, to draw the design changes required for the automation and to calculate the supposed solution.This pilot study has resulted in a suggested automation solution using laser as a heat source for soldering. Calculations of the solution show that a automating a laser soldering cell is very profitable..

Laserskärning i Sverige : ? tekniken, marknaden och hur de utvecklas

Laser for material processing possesses a number of advantages which mean that it has been and will be an important component for a wide range of industries' future development. Cutting materials processing is the dominant use of laser technology and has revolutionized the manufacturing industry. The aim of this thesis is to describe the principles of metal cutting by laser, how laser cutting is applied in practice and to identify how Swedish companies are using laser cutting. For the theoretical and technical description of laser cutting literature studies are the primary source of information. The empirical basis for the mapping of the Swedish industry for laser cutting is grounded on a survey; this includes Swedish companies that use laser cutting in their production.

Laserprojektor

This report describes a thesis project on 15hp. The purpose of the thesis project is to build a laser projector that reacts on sound waves and thus get a laser beam to draw visualizations of sound waves on a wall. The idea was that the design would be independent and not have to be plugged into any audio equipment. This was achieved by absorbing sound waves into a microphone. Another factor was to get a ?do it yourself? -feeling of the design and therefore it was chosen to be constructed using for example, old hard-drives.The result was a relatively large and bulky designed laser projector that can draw sound waves on a wall..

Segmentering och klassificering av LiDAR-data

With numerous applications in both military and civilian life, the demand for accurate 3D models of real world environments increases rapidly. Using an airborne laser scanner for the raw data acquisition and robust methods for data processing, the researchers at the Swedish Defence Research Agency (FOI) in Linköping hope to fully automate the modeling process.The work of this thesis has mainly been focused on three areas: ground estimation, image segmentation and classification. Procedures have in each of these areas been developed, leading to a new algorithm for ground estimation, a number of segmentation methods as well as a full comparison of various decision values for an object based classification. The ground estimation algorithm developed has yielded good results compared to the method based on active contours previously elaborated at FOI. The computational effort needed by the new method has been greatly reduced compared to the former, as performance, particularly in urban areas, has been improved.

Laserinkopplingselement För XFEL Laser Heater : Från Idé Till Färdig Produkt I Designstadie

Uppsala University is involved in a large international collaborationto build the Laser heater system for the European Xray Free-electronlaser in Hamburg, Germany. In this thesis I describe a laser incouplingdevice into the vacuum chamber of this laser heater all the way fromthe specifications to a completed design.The laser heater is a very important part of the XFEL and thepart described here is a part of the vacuum system needed to couplean external laser into the electron vacuum system and align it withthe electron bunches in order to heat them. The task was started by studying the literature about the basic theory andthe design of vacuum systems. After this study and collection of ideaswith colleagues I started to prepare different concepts to solve thetask. The ideas can be put into two categories, in one case the couplingmirror is located inside the vacuum chamber and in the second caseoutside.

Mätning av stamdiameter med markstående scanner :

Booth for operational planning of harvesting and for long term planning, data is today collected manually. Intensive objective field inventories are usually too expensive. To enhance optimisation of timber flow from forest to industry Moore efficient methods for measuring tree stems of standing trees are needed. The performance of terrestrial laser scanners have improved and these could possibly be used within forestry in the future. The objective of this study was to validate how a terrestrial laser scanner could be used to measure stem diameter, and to test how the errors depend on distance from the scanner and tree species. Two plots (one pine and one spruce) were used for this study.

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