| 31. |
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| 32. |
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| 33. |
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| 34. |
- Eklundh, L.
(author)
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Tillförlitlig global vegetationsinformation fran satellitdata-optimism eller realitet?
- 1997
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In: Svensk Geografisk Arsbok. - 0081-9808. ; 73, s. 7-15
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Journal article (peer-reviewed)abstract
- The continuous operation of the NOAA series of meteorological satellites from the early 1980s onward, and the use of time series of data from its AVHRR sensor have been instrumental in the development of a new paradigm in the area of global earth observation. The coarse spatial and high temporal resolution of the data contrasts sharply with the data characteristics of traditional earth resource satellites, such as Landsat and SPOT, with their high spatial and low temporal resolution. Numerous scientists have demonstrated the potential of the data for capturing seasonal variations in terrestrial vegetation. The enthusiam of researchers has led them to use time series of ANHRR data for almost every conceivable type of study, from mapping of deserts and forests to the monitoring of ecological conditions for locust infestations and the spread of malaria by mosquitoes, AVHRR data are not being used operationally in programmes issuing early warnings for drought and famine in semi-arid areas. However, studies of the quality of the data cast some doubts over previous optimism. How do we come to terms with the contradictory results and what are the implications for the future use of the data?.
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| 35. |
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| 36. |
- Franzén, Lars, 1950, et al.
(author)
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Small Scale Glacial Erosion Forms and Their Possible Relation to Post-Glacial Weathering
- 1991
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In: Geografiska Annaler. - 0435-3676 .- 1468-0459. ; 73:1, s. 1-7
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Journal article (peer-reviewed)abstract
- The paper describes several types of small scale forms on the stoss side of a roche moutonnee surface, recently exposed in a gravel pit in the Fjaras bracka complex, SW Sweden. The forms were filled with weathered rock debris. When excavated, they showed a striking resemblance to 5 forms generally accepted to be shaped by glacial/glaciofluvial erosion. In addition to these forms there were irregular cavities for instance smoothly rounded throughs and irregular rough surfaces resembling those claimed to be preglacial weathering forms. In spite of the few observations made, many small scale glacial erosion forms are likely to be the result of a three-step process i.e. glacial pressure deformation of the bedrock, subsequent weathering of the deformed rock, and finally excavation of the deformed rock by exogenic processes. Further on it seems probable that many rough surfaces of the type described in the paper are the result of glacial pressure deformation and subsequent weathering
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| 37. |
- Hall, Karin
(author)
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Crop Monitoring in Sweden
- 1989
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In: International Journal of Remote Sensing. - 1366-5901. ; , s. 461-484
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Journal article (peer-reviewed)
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| 38. |
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| 39. |
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| 40. |
- Harrie, Lars
(author)
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Generalisation Methods for Propagating Updates between Cartographic Data Sets
- 1998
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Licentiate thesis (other academic/artistic)abstract
- Automation is increasingly important in producing and maintaining cartographic data sets. This thesis deals with automatic methods to propagate updates between cartographic data sets. The major idea is to update only the most detailed data set (master data set) and then propagate these updates automatically to less detailed data sets (target data sets). The approach used is firstly to formulate linguistic rules for the update process. The information sources for these linguistic rules are data set specifications, cartographic data sets, paper maps and practising cartographers. These linguistic rules are translated into logical rules and then implemented in a prototype system. The prototype system is built on top of an object-oriented map production software. The system requires a multiple representation database, which consists of cartographic data sets at different scales together with connectivities between those objects that refer to the same physical entities. The prototype system is built on a conceptual framework of four steps: examination, propagation, generalisation of updates and solving spatial conflicts. The aim of the examination step is to determine which object should be created, modified or deleted in the target data set. The action is dependent on the current status of the target data set and the properties of the update to the master data set. The propagation step executes the outcome of the examination step. Furthermore, this step validates the updates and maintains the integrity of the multiple representation database. In the next step – generalisation of updates – the new or modified object in the target data set is generalised to suit the scale of the target data set. The final step treats spatial conflicts due to the update. A new method is proposed for solving spatial conflicts, called the constraint method, which is a generic method that resembles manual generalisation on a conceptual level.
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