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| 2. |
- Eklundh, Lars, et al.
(författare)
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High resolution mapping of vegetation dynamics from Sentinel-2
- 2012
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Ingår i: Proceedings of 1st Sentinel-2 Preparatory Symposium. - 0379-6566. - 9789290922711 ; 707 SP
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Konferensbidrag (refereegranskat)abstract
- The aim of this work is to develop and test a method for generation of information on vegetation dynamics from high-spatial resolution data, such as Sentinel-2. In order to accomplish this, Sentinel-2 data were simulated from existing SPOT HRG and HRVIR scenes over Sweden. We used TIMESAT, a well-tested computer package for generating smooth seasonal profiles and generation of seasonality parameters, like start and end, length, amplitude, integrated values, seasonal maximum, derivatives, etc. The processing works on a pixel-by-pixel basis and is resistant to clouds and noise. Data gaps are handled, and quality information can be included to increase the fidelity of the fits. The pilot study demonstrated that TIMESAT was successful in fitting smooth model functions to the data, and generating seasonality parameters for the test area at 10 × 10 m resolution. We conclude that TIMESAT will be useful for generating vegetation dynamics data from high-spatial resolution data such as Sentinel-2. The smooth seasonal profiles will be extremely useful for driving high-resolution biophysical vegetation models, and the seasonality parameters will be excellent for change detection, and for studying trends in vegetation productivity and seasonality.
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| 3. |
- Feldt, Robert, et al.
(författare)
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Analyzing the cost of complying to the ECSS standards for software development
- 2010
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Ingår i: European Space Agency, (Special Publication) ESA SP. Conference on DAta Systems in Aerospace, DASIA 2010; Budapest; 1-4 June 2010. - Budapest : European Space Agency. - 0379-6566. - 9789290922469 ; 682, s. 303-307
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Konferensbidrag (refereegranskat)abstract
- Software for space applications has special requirements in terms of reliability and dependability. Standards are one of the primary mechanisms to ensure a sufficient quality level, with the European Cooperation on Space Standardization (ECSS) standards being the main ones. The use of standards is not only a benefit since they can incur considerable costs in terms of, for example, additional documentation and activities. For making the right decisions on which development and quality assurance activities to focus on it is important to know not only their added value but also their costs. Here we present a method for analyzing the cost of standard compliance (CoSC) in software development. It is based on a model which divides the costs into four different types based on their primary value: development, quality-adding, confidence-adding and adherence. The adherence costs are those costs that are incurred by or follows from the use of a standard but does not add any immediate value to either the functionality, quality or quality assurance of the software. Initial results from applying the method in an industrial company adhering to ECSS is presented.
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| 4. |
- Feldt, Robert, et al.
(författare)
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Optimizing Verification and Validation Activities for Software in the Space Industry
- 2010
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Ingår i: European Space Agency, (Special Publication) ESA SP. Conference on DAta Systems in Aerospace, DASIA 2010; Budapest; 1-4 June 2010. - Budapest : European Space Agency. - 0379-6566. - 9789290922469 ; , s. 309-313
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Konferensbidrag (refereegranskat)abstract
- Software for space applications has special requirements in terms of reliability and dependability and the verification & validation activities (VAs) of these systems often account for more than 50% of the develop- ment effort. The industry is also faced with political and market pressure to deliver software faster and cheaper. Thus new ways are needed to optimize these activities so that high quality can be retained even with reduced costs and effort. Here we present a framework for the management and optimization of verification & validation activities (VAMOS). An initial evaluation of the framework based on historical data as well as data extracted with a new tool has been done and are described briefly.
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| 5. |
- Pathan, Risat, 1979, et al.
(författare)
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Temporal Partitioning on Multicore Platform
- 2014
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Ingår i: European Space Agency, (Special Publication) ESA SP. - 0379-6566. - 9789292212896 ; SP 725
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Konferensbidrag (refereegranskat)abstract
- This paper addresses the problem of ensuring temporal partitioning according to the ARINC-653 standard for integrating multiple applications on the same multicore platform. To employ temporal partitioning, we propose the design and analysis of a hierarchical scheduling framework (HSF) for multicore platform. In HSF, each application has a server task, which is mapped to one of the physical cores of the multicore platform. The HSF framework is based on scheduling at two-levels: (i) a system-level scheduler for each core schedules the server tasks that are mapped to that core, and (ii) a task-level scheduler for each application schedules the tasks of the application. This paper presents the design and analysis of this two-level HSF that can be used to ensure temporal partitioning and meeting all the deadlines of each application tasks. The effectiveness of our technique is demonstrated using real-world space applications provided by RUAG Space Sweden AB.
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| 6. |
- Persson, Henrik, et al.
(författare)
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Estimation of forest variables using radargrammetry on TerraSAR-X data in combination with a high resolution DEM
- 2013
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Ingår i: Esa Sp. - 0379-6566. ; 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This study uses the backscattered intensity information from SAR images acquired with TerraSAR-X to derive Digital Surface Models with radargrammetry. Then the known ground elevation (from airborne lidar) is subtracted to get Canopy Height Models that are analysed and linked through regression analysis to the forest variables above-ground biomass and tree height. It was found, that the used constellation of image pairs and prediction models produced biomass estimations at stand level with 25.9% and 33.8% relative RMSE, while the height estimations were 11.5% and 12.3%. The analyses were tested at the Swedish test sites Krycklan and Remningstorp.
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