| 1. |
- Bäck, Daniel, 1982, et al.
(författare)
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Analysis of C-band polarimetric signatures of Arctic lead ice using data from AIRSAR and RADARSAT-1
- 2008
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Ingår i: 2008 IEEE International Geoscience and Remote Sensing Symposium - Proceedings; Boston, MA; United States; 6 July 2008 through 11 July 2008. - 9789292212209 ; :1, s. 184-187
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In December 2004 the JPL airborne synthetic aperture radar (AIRSAR) flown on the NASA DC-8 acquired fully polarimetric data in the Beaufort Sea at C, L and P-band. This work presents the backscatter coefficients (sHH, sVV, sHV), copolarized ratios (sHH/sVV) and copolarized phase differences (?HH-VV) at C-band from different young sea-ice types formed in recently frozen leads. Two weeks of RADARSAT-1 imagery from the same region as the AIRSAR data were used in order to identify when and where leads were formed and to estimate the age of the newly formed ice contained within the leads. A known empirical relationship based on freezing degree days was used to estimate the sea-ice thickness. The results indicate that some of the identified thin ice types have characteristic signatures.
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| 2. |
- Sahlin, Eva A.U. 1971-, et al.
(författare)
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Connectivity analyses of valley patterns reveal Devensian glacial drainage activity in Mid-Wales (poster)
- 2009
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Coastal valleys in the west part of Mid-Wales, such as the Mawddach, Dysynni, Tal-y-llyn and Dyfi, are believed to have acted as corridors for ice which drained the Welsh Ice Cap during the Devensian. Connectivity analyses of valley patterns from detailed digital elevation models, and interpretation of satellite images and aerial photographs show the existence of large variations in the amount of glacial modification between these valleys. Although all the valleys are glacially over-deepened along Silurian fault lines, only the Dyfi basin exhibits a dendritic pattern, with V-shaped cross profiles and valley spurs typical of valleys formed by fluvial processes.The connectivity analyses show that the Dyfi basin exhibits a purely dendritic pattern with little glacial modification of the preglacial fluvial valley pattern in form of valley breaching. It is proposed here that the general river valley morphology of the Dyfi basin is of a pre-Late Devensian age. This suggests a complex glacial drainage history, where cold-based ice was not only confined to the interior uplands, but also covered low-altitude areas previously believed to be a major drainage conduit for the Welsh Ice Cap. This indicates that Late Devensian glacial erosion was not as intense as previously believed and larger areas might have been overlain by cold-based ice.
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| 3. |
- Sahlin, Eva A.U. 1971-, et al.
(författare)
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Evidence for cold-based ice at low altitudes : Preservation of a preglacial fluvial valley system in the Dyfi basin, Wales (poster)
- 2009
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Coastal valleys in the west part of mid-Wales, such as the Mawddach, Dysynni, Tal-y-llyn and Dyfi, are believed to have acted as corridors for ice which drained the Welsh Ice Cap during the Devensian. Analysis of detailed digital elevation models and interpretation of satellite images and aerial photographs show the existence of large variations in the amount of glacial modification between these valleys. Although all the valleys are glacially over-deepened along Silurian fault lines, only the Dyfi basin exhibits a dendritic pattern, with V-shaped cross profiles and valley spurs typical of valleys formed by fluvial processes. Connectivity analysis of the Dyfi basin shows that it exhibits a nearly dendritic pattern with connectivity α and β values of 0.74 and 1.01 respectively, with little glacial modification of the preglacial fluvial valley pattern in the form of valley breaching. It is proposed that the general river valley morphology of the Dyfi basin is of a pre-Late Devensian age. Several examples have been identified of glacial meltwater incision into a well-developed pre-existing river valley system, causing river capture across watersheds. The degree of preservation of the pre-glacial fluvial valley system within the Dyfi basin indicates limited modification by glacial processes, despite the area being subjected to Late Devensian glacier activity. It is possible that major parts of the basin were covered by cold-based or slow-moving ice close to or under a migrating ice divide, with the major ice drainage occurring along the weaker zone of the Pennal Fault, causing minor adjustments to the surrounding interfluves and uplands.
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| 4. |
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| 5. |
- Fransson, J.E.S., et al.
(författare)
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Detection of clear-cuts using ALOS PALSAR satellite images
- 2008
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Ingår i: Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR. - 2197-4403. ; 1-4
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Konferensbidrag (refereegranskat)abstract
- The objective of this study is to make a first evaluation of the possibilities to detect forest clear-cuts using high-resolution ALOS PALSAR FBD (Fine Beam Dual polarization) satellite images. New operational applications for mapping of changes in forest cover are of interest for government authorities in Sweden and in other countries with similar needs. The study was conducted in southern Sweden and included seven old coniferous stands located on flat terrain. Three of the stands were clear-felled and the remaining stands were left untreated for reference. Altogether, six PALSAR FBD images (look angle 34.3°, HH- and HV-polarization) acquired during the summer and fall seasons were analyzed. The difference in backscattering coefficient between the reference and the clear-felled stands was on average 2.4 dB and 2.9 dB for the HH- and HV-polarization, respectively. When comparing the backscattering coefficient before and after clear-felling the drop was found to be 1.7 dB and 2.3 dB for the HH- and HV-polarization, respectively.
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| 6. |
- Lundberg, C., et al.
(författare)
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Evaluation of robot deployment in live missions with the military, police, and fire brigade
- 2007
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Ingår i: Sensors, and Command, Control, Communications and Intelligence (C31) Technologies for Homeland Security and Homeland Defense VI. - : SPIE - International Society for Optical Engineering. - 0819466603 - 9780819466600 ; , s. 65380R-
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Konferensbidrag (refereegranskat)abstract
- Robots have been successfully deployed within bomb squads all over the world for decades. Recent technical improvements are increasing the prospects to achieve the same benefits also for other high risk professions. As the number of applications increase issues of collaboration and coordination come into question. Can several groups deploy the same type of robot? Can they deploy the same methods? Can resources be shared? What characterizes the different applications? What are the similarities and differences between different groups? This paper reports on a study of four areas in which robots are already, or are about to be deployed: Military Operations in Urban Terrain (MOUT), Military and Police Explosive Ordnance Disposal (EOD), Military Chemical Biological Radiological Nuclear contamination control (CBRN), and Fire Fighting (FF). The aim of the study has been to achieve a general overview across the four areas to survey and compare their similarities and differences. It has also been investigated to what extent it is possible for the them to deploy the same type of robot. It was found that the groups share many requirements, but, that they also have a few individual hard constrains. A comparison across the groups showed the demands of man-portability, ability to access narrow premises, and ability to handle objects of different weight to be decisive; two or three different sizes of robots will be needed to satisfy the need of the four areas.
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| 7. |
- Hu, Yunfeng, et al.
(författare)
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The Trajectory of Urbanization Process in the Yangtze River Delta During 1990 to 2005
- 2009
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Ingår i: 2009 JOINT URBAN REMOTE SENSING EVENT. - NEW YORK : IEEE. - 9781424434602 ; , s. 407-414
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Konferensbidrag (refereegranskat)abstract
- Rapid economic development, combined with tremendous population growth and migration from rural areas, has resulted in a dramatic urbanization in the Yangtze River Delta over the last three decades. In order to develop a more quantitative understanding of urbanization trajectory in the Yangtze Delta from the late 1980s to 2005, the time-series national land cover/land-use database (NLCD), interpreted from remote sensing imagery (including Landsat TM, ETM+ and CBERS), was examined from the aspects of spatial pattern and temporal process. The results showed that the urban land in the Yangtze River Delta has increased from 2.29x10(3) km(2) in the late 1980s to 4.19x10(3) km(2) in 2005. The percentages of total land area in the Yangtze Delta occupied by urban environments in the late 1980s, 1995, 2000 and 2005 were 2.09%, 3.03%, 3.28%, and 3.82% respectively. During the late 1980s - 2005, the total urban expansion in this region was 1.92x10(3) km(2), resulting in an annual urban expansion area (UXa) of about 118.72 km(2) per year, with an urban erpansion intensity (UXt)of 83.03%. There were significant spatial trends and differences in urbanization level and urban expansion. Most urban land and urban expansion have occurred along the Huning Railway (Shanghai-Nanjing) and the Hanzhou Bay. This study also revealed substantial temporal differences in the rate at which urban areas have expanded. There was a great deal of urban growth in the late 1980s - 1995, and also in 2000 - 2005. The 1995 - 2000 period saw a slow expansion speed due to government initiatives designed to hall the loss of agricultural land. In this study, both patterns and dynamics of urban distribution and urban expansion were examined on temporal and spatial scales, and integrated to produce a comprehensive evaluation of recent urbanization trajectory in the Yangtze River Delta.
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| 8. |
- Luo, L., et al.
(författare)
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Consistency testing of IP in mixed-signal SoC
- 2007
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Ingår i: 2007 8th International Conference on Electronic Measurement and Instruments, ICEMI. - : IEEE. - 1424411351 - 9781424411351 ; , s. 265-268
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Konferensbidrag (refereegranskat)abstract
- Based on the discussion, on the consistency description method used for SoC design, the testing method about the operation consistency of IP (Intellectual Property) blocks is addressed in this paper. The method proposed the guidance for designing the test vectors in mixed signal SoC design. With the method, logical description of operation consistency specification can be built in SoC design. This paper indicates that operation consistency design is a key point and will impact both architecture of hardware and software.
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| 9. |
- Rymasheuskaya, Maryna
(författare)
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Comparison of several change detection methods for monitoring land cover dynamics in Belarus
- 2007
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Ingår i: Proceedings of MultiTemp 2007 - 2007 International Workshop on the Analysis of Multi-Temporal Remote Sensing Images. - 1424408466 - 9781424408467 ; , s. 4293063-
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Konferensbidrag (refereegranskat)abstract
- The study presents experience of use of post-classification comparison, image differencing, principal component analysis, use of ancillary data and combinations of different change detection methods for detecting land cover / land use dynamics in Novopolotsk area, Belarus over the period 1994-2002. All methods give good results in terms of accuracy assessment, visual presentation, etc. Change detection results are dependent on parameters applied.
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| 10. |
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