• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2787
  • 1063
  • 430
  • 233
  • 222
  • 130
  • 48
  • 42
  • 41
  • 41
  • 41
  • 41
  • 41
  • 41
  • 40
  • Tagged with
  • 6056
  • 4409
  • 984
  • 909
  • 563
  • 520
  • 489
  • 469
  • 417
  • 377
  • 374
  • 368
  • 361
  • 359
  • 358
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Obstacle avoidance control in the vertical plane for the REMUS autonomous underwater vehicle /

Chuhran, Christopher D. January 2003 (has links) (PDF)
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Anthony J. Healey. Includes bibliographical references (p. 45). Also available online.
12

Texture analysis of high resolution panchromatic imagery for terrain classification /

Humphrey, Matthew Donald. January 2003 (has links) (PDF)
Thesis (M.S. in Applied Physics)--Naval Postgraduate School, June 2003. / Thesis advisor(s): Richard C. Olsen, Alan A. Ross. Includes bibliographical references (p. 127-129). Also available online.
13

A comprehensive analysis of terrestrial surface features using remote sensing data

Sun, Liqun, 孙立群 January 2014 (has links)
Using the remote sensing data, this study aims to enhance our understanding of land surface features, including ecosystem distribution in association with topographic controls and climatic controls, vegetation disturbance due to natural hazards, and surface temperature changes with consideration of the influence of urbanization. In this study, the Global Inventory Monitoring and Modeling System (GIMMS) Normalized Difference Vegetation Index (NDVI) data sets from 1982 to 2006 were used to explore vegetation variation. A data mining method, Exhaustive Chi-squared Automatic Interaction Detector algorithm, was successfully applied to investigate the topographic influences on vegetation distribution in China. The study revealed that elevation is a predominant factor for controlling vegetation distribution among different topographic attributes (slope, aspect, Compound Topographic Index (CTI) and distance to the nearest river). Further, the study results indicated that solar radiation is the limited factor for plant growth in majority of the Northern Hemisphere in summer, and temperature is the main limitation for other seasons. Partial correlation coefficient (PCC) method was adopted to investigate the complex relationships of NDVI with weather variables (i.e., temperature, precipitation and solar radiation) and key climate indices (such as, El Niño-Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), Arctic Oscillation (AO), and Antarctic Oscillation (AAO)). The study indicated that AO is the most significant index in affecting the temperatures in spring and winter in the Northern Hemisphere. This study enhanced the understanding of vegetation responds to asymmetric daytime (Tmax) and nighttime (Tmin) warming in different seasons. The result revealed that asymmetric warming of Tmax and Tmin may influence vegetation photosynthesis and respiration in the plant growth in different periods across biomes. In spring and autumn, vegetation in boreal and wet temperate regions of the Northern Hemisphere is positively correlated with Tmax and negatively correlated with Tmin, whereas, in dry regions the NDVI is always negatively correlated with Tmax and positively correlated with Tmin. In summer, the NDVI is negatively correlated with Tmax in many dry regions. In addition, this study developed a new index, Continued Vegetation Decrease Index (CVDI), to detect vegetation disturbance due to extreme natural hazards (such as, earthquake, wildfire, ice storms and so on). Using the Wenchuan earthquake occurred in Sichuan China on 12 May 2008 as an example, this study confirmed that the CVDI method can effectively identify the regions with severe vegetation damage, and it is expected that the newly-developed index can be used for detecting vegetation disturbance in other regions of the world. Finally, using the remote sensing data (land use data and surface temperature data) and weather station data, this study developed a new method to evaluate the urbanization influence on the temperature recorded at weather stations. The results revealed that the weather stations with most fast increase temperature are not in developed countries, but in developing countries. The results also imply that the global warming trend may be overestimated due to the under-estimation of urbanization influence on temperature increase. / published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy
14

A Remote sensing change detection study in the arid Richtersveld region of South Africa.

Main, Russell Stuart. January 2007 (has links)
<p>The Richtersveld falls within the succulent karoo and dester biomes. This studu made use of remote sensing technologies in order to investigate possible vegetation cover changes that have taken place over time, and which have manifested through a combination of threats to the region. Te aims of the study were adressed using three key questions that sought to gainan understanding of the relationship between vegetation response and moisture, in order to interpret teporal and spatial vegetyation cover changes. A spartially and temporarily representative remotely sensed dataset was used together with techniques that are repeatable and able to quantify change with a limited human bias.</p>
15

A Remote sensing change detection study in the arid Richtersveld region of South Africa.

Main, Russell Stuart. January 2007 (has links)
<p>The Richtersveld falls within the succulent karoo and dester biomes. This studu made use of remote sensing technologies in order to investigate possible vegetation cover changes that have taken place over time, and which have manifested through a combination of threats to the region. Te aims of the study were adressed using three key questions that sought to gainan understanding of the relationship between vegetation response and moisture, in order to interpret teporal and spatial vegetyation cover changes. A spartially and temporarily representative remotely sensed dataset was used together with techniques that are repeatable and able to quantify change with a limited human bias.</p>
16

Hyperspectral remote sensing and the urban environment : a study of automated urban feature extraction using a CASI image of high spatial and spectral resolution /

Arkun, Sedat. January 1999 (has links) (PDF)
Thesis (Master of Spatial Information Science) -- University of Adelaide, Key Centre for Social Applications of Geographical Information Systems, 1999. / Includes bibliography.
17

An investigation into underwater navigation accuracy with regard to sensor combinations and quality /

Herselman, Leo. January 2008 (has links)
Thesis (MScIng)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.
18

Satellite mapping and automated feature extraction geographic information system-based change detection of the Antarctic coast /

Kim, Kee-Tae, January 2003 (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xiv, 157 p.; also includes graphics. Includes bibliographical references (p. 143-148).
19

Tracking control of autonomous underwater vehicles /

Keller, Joseph J. January 2002 (has links) (PDF)
Thesis (Mechanical Engineer and M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2002. / Thesis advisor(s): Anthony J. Healey. Includes bibliographical references (p. 67-68). Also available online.
20

Design of an autonomous underwater vehicle : vehicle tracking and position control /

Holtzhausen, Servaas. January 2010 (has links)
Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010. / Full text also available online. Scroll down for electronic link.

Page generated in 0.0669 seconds