High coherence photon pair source for quantum communication

This paper reports a novel single mode source of narrow-band entangled photon pairs at telecom wavelengths under continuous wave excitation, based on parametric down conversion. For only 7 mW of pump power it has a created spectral radiance of 0.08 pairs per coherence length and a bandwidth of 10 pm (1.2 GHz). The effectively emitted spectral brightness reaches 3.9*10^5 pairs /(s pm). Furthermore, when combined with low jitter single photon detectors, such sources allow for the implementation of quantum communication protocols without any active synchronization or path length stabilization. A HOM-Dip with photons from two autonomous CW sources has been realized demonstrating the setup's stability and performance.Comment: 12 pages, 4 figure

Plant discrimination by Support Vector Machine classifier based on spectral reflectance

Support Vector Machine (SVM) algorithms are developed for weed-crop discrimination and their accuracies are compared with a conventional data-aggregation method based on the evaluation of discrete Normalised Difference Vegetation Indices (NDVIs) at two different wavelengths. A testbed is especially built to collect the spectral reflectance properties of corn (as a crop) and silver beet (as a weed) at 635 nm, 685 nm, and 785 nm, at a speed of 7.2 km/h. Results show that the use of the Gaussian-kernel SVM method, in conjunction with either raw reflected intensities or NDVI values as inputs, provides better discrimination accuracy than that attained using the discrete NDVI-based aggregation algorithm. Experimental results carried out in laboratory conditions demonstrate that the developed Gaussian SVM algorithms can classify corn and silver beet with corn/silver-beet discrimination accuracies of 97%, whereas the maximum accuracy attained using the conventional NDVI-based method does not exceed 70%

NASA SBIR abstracts of 1991 phase 1 projects

The objectives of 301 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1991 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 301, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1991 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included

Aeronautics and space report of the President, 1982 activities

Achievements of the space program are summerized in the area of communication, Earth resources, environment, space sciences, transportation, aeronautics, and space energy. Space program activities of the various deprtments and agencies of the Federal Government are discussed in relation to the agencies' goals and policies. Records of U.S. and world spacecraft launchings, successful U.S. launches for 1982, U.S. launched applications and scientific satellites and space probes since 1975, U.S. and Soviet manned spaceflights since 1961, data on U.S. space launch vehicles, and budget summaries are provided. The national space policy and the aeronautical research and technology policy statements are included

Report on active and planned spacecraft and experiments

Information is presented, concerning active and planned spacecraft and experiments known to the National Space Science Data Center. The information included a wide range of disciplines: astronomy, earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. These spacecraft projects represented the efforts and funding of individual countries as well as cooperative arrangements among different countries

Analytical techniques: A compilation

A compilation, containing articles on a number of analytical techniques for quality control engineers and laboratory workers, is presented. Data cover techniques for testing electronic, mechanical, and optical systems, nondestructive testing techniques, and gas analysis techniques

Application of advanced technology to space automation

Automated operations in space provide the key to optimized mission design and data acquisition at minimum cost for the future. The results of this study strongly accentuate this statement and should provide further incentive for immediate development of specific automtion technology as defined herein. Essential automation technology requirements were identified for future programs. The study was undertaken to address the future role of automation in the space program, the potential benefits to be derived, and the technology efforts that should be directed toward obtaining these benefits

Design and development of an unmanned aerial and ground vehicles for precision pesticide spraying

Günümüzde, bitki hastalıkları tarımsal üretimi etkileyen önemli sorunlardan birisi olarak karşımıza çıkmaktadır. Bitkileri hastalıklardan ve zararlı otların etkilerinden korumak hem tarımda üretimi artırmak hem de tarımın kalitesini yükseltmek için büyük önem taşımaktadır. Tarımsal ürünler, ülkemizde ve dünyada çeşitli ilaçlama yöntemleri kullanılarak korunabilmektedir. Bu yöntemlerin başında gelen ilaçlama yolu ile bitki koruma yöntemi üretimin kalitesini geliştirmek ve rekolteyi artırmak amacıyla yaygın olarak kullanılmaktadır. Ancak bitkilerin korunmasında uygulanan geleneksel ilaçlama yöntemlerinin bitkilere ve toprağa büyük ölçüde zarar verdiği gözlenmektedir. Son yıllarda gelişmiş ülkelerdeki tarımsal uygulamalarda robotların kullanımı hızla artmakta, tarımsal alanlarda özellikle uzaktan algılama ve hassas tarım çalışmalarında bu robotların kullanıldığı görülmektedir. Dahası, tarımsal üretimde yararlanılan fayda-maliyet oranı da dikkate alındığında, günümüzde hassas tarım uygulamalarında robotların kullanılmasının kaçınılmaz hale geldiği anlaşılmaktadır. Günümüz gereksinimleri ve gelişen teknoloji göz önüne alınarak planlanmış olan bu çalışmada, ülkemizde yaygın olarak kullanılan tarımsal mücadele yöntemlerinin maliyetlerini, tarımsal üretimin miktarını ve kalitesini önemli ölçüde etkileyecek geleneksel ilaçlama yöntemlerine alternatif olabilecek bir tarımsal mücadele sistemi geliştirilmiştir. Çalışmada, yakın mesafeden doğrudan hedeflenen bitki üzerine ilaçlama yapılması, ilaçlama sırasında toprağa ve bitkilere verilen zararın en aza indirgenmesi hedeflenmiştir. Bu doğrultuda, özgün tasarım multispektral kamera, ilaçlama ünitesi, Yer Kontrol İstasyonu (YKİ) ve eşgüdümlü çalışabilen İnsansız Hava Aracı (İHA) ile İnsansız Yer Aracından (İYA) oluşan tarımsal mücadele mekanizması tasarlanmış ve geliştirilmiştir. Bu mekanizma, tarımsal ilaçlama uygulamaları için geleneksel yöntemlere kıyasla daha ileri düzey bir alternatif yöntem olarak ortaya çıkmaktadır.TABLE OF CONTENTS ÖZET ................................................................................................................ vii ABSTRACT ....................................................................................................... ix ACKNOWLEDGEMENTS ................................................................................ xi 1 . INTRODUCTION .......................................................................................... 1 2. LITERATURE REVIEW ............................................................................. 6 2.1 Robotics ..................................................................................................... 9 2.2 Unmanned Ground Vehicles ..................................................................... 11 2.3 Unmanned Aerial Vehicles ....................................................................... 11 2.4 Remote Sensing Technology .................................................................... 17 2.4.1 Remote Sensing Platforms ................................................................. 19 2.4.2 Plant Disease Detection ..................................................................... 22 2.4.3 Normalized Difference Vegetation Index ........................................... 27 3 . MATERIAL AND METHOD ....................................................................... 29 3.1 Ground Control Station ............................................................................ 32 3.2 Unmanned Ground Vehicle ...................................................................... 37 3.2.1 Specifications of the UGV ................................................................. 38 3.2.2 The Chassis and Sensor Holder .......................................................... 40 3.2.3 FEM Analysis .................................................................................... 43 3.3 Multispectral Camera for Plant Disease Detection .................................... 44 3.3.1 Spectral Imaging ................................................................................ 46 3.3.2 Multispectral Camera – Spektra TSL128RN ...................................... 47 3.3.3 The hardware of the Device ............................................................... 49 3.3.4 Calibrating Steps of the Device .......................................................... 52 3.3.5 Software for the Device ..................................................................... 56 3.3.6 Measurements using NDVI Devices .................................................. 58 3.4 Unmanned Aerial Vehicle ........................................................................ 62 3.4.1 The Chassis and Arm ......................................................................... 66 3.4.2 FEM Analysis ................................................................................... 69 3.4.3 Modal Analysis ................................................................................. 70 3.4.4 Performance of the Propellers ............................................................ 73 3.4.5 Flight Duration and Maximum Conditions ......................................... 82 3.4.6 Strain Measurement ........................................................................... 84 3.4.7 Other Parts ........................................................................................ 92 3.4.8 Specifications of the UAV ................................................................. 95 3.4.9 Flight Tests ....................................................................................... 96 3.5 Spraying Unit –Sprayer and Tank ............................................................. 99 4 . RESULTS AND DISCUSSION .................................................................. 103 4.1 The UGV ............................................................................................... 103 4.2 The Multispectral Camera ...................................................................... 105 4.3 The UAV ............................................................................................... 115 4.4 The Sprayer............................................................................................ 135 xv 4.5 UGV and Multispectral Camera .............................................................. 138 4.6 Aerial Spraying UAV ............................................................................. 145 5 . CONCLUSIONS......................................................................................... 154 REFERENCES ................................................................................................ 156 RESUME......................................................................................................... 16

Data catalog series for space science and applications flight missions. Volume 4A: Descriptions of meteorological and terrestrial applications spacecraft and investigations

The National Space Science Data Center (NSSDC) provides data from and information about space science and applications flight investigations in support of additional studies beyond those performed as the principal part of any flight mission. The Earth-orbiting spacecraft for investigations of the earth and its atmosphere is discussed. Geodetic tracking data are included in this category. The principal subject areas presented are meteorology and earth resources survey, and the spacecraft selection is made according to those subjects. All experiments on board the spacecraft are described. No attempt is made to reference investigations that are related to the above disciplines, but that are described in other volumes of this series

Present and future of surface-enhanced Raman scattering

The discovery of the enhancement of Raman scattering by molecules adsorbed on nanostructured metal surfaces is a landmark in the history of spectroscopic and analytical techniques. Significant experimental and theoretical effort has been directed toward understanding the surface-enhanced Raman scattering (SERS) effect and demonstrating its potential in various types of ultrasensitive sensing applications in a wide variety of fields. In the 45 years since its discovery, SERS has blossomed into a rich area of research and technology, but additional efforts are still needed before it can be routinely used analytically and in commercial products. In this Review, prominent authors from around the world joined together to summarize the state of the art in understanding and using SERS and to predict what can be expected in the near future in terms of research, applications, and technological development. This Review is dedicated to SERS pioneer and our coauthor, the late Prof. Richard Van Duyne, whom we lost during the preparation of this article