This work examines the effectiveness of spaceborne synthetic aperture radar (SAR) for investigating seasonally variable glaciological parameters, in particular its ability to discriminate glacier surface facies in order to estimate glacier mass balance. A multitemporal C-band SAR dataset of Nordenskiold Land, Spitsbergen, acquired by the ERS-1 satellite, is used for the analysis, which focuses on mountain glaciers rather than ice sheets. Validating field measurements of ice and snowpack parameters were obtained contemporaneously with two SAR images, prior to and during the ablation season. A general model for the annual backscatter cycle from a sub-polar glacier is derived from SAR data of three glacierised areas. This model reveals two seasonal reversals in the relative magnitude of backscatter from the ice and wet-snow facies, principally through a 10 dB change in the latter; these reversals mark the start and end of the ablation season. It is shown that a combination of winter and summer SAR imagery is necessary to estimate the equilibriumline altitude of a sub-polar glacier. Topographic distortion is the major limiting factor regarding the utilisation of SAR data for studying mountainous glaciers. Existing theoretical models of radar backscatter from snow and ice are validated for three scenarios: glacier ice, dry snow overlying glacier ice, and wet snow, using the in situ measurements. In addition, temporal variations of ice and snowpack parameters observed during the field campaigns are used to predict short-term seasonal changes in backscatter, and to corroborate the model of annual backscatter. ERS-1 SAR data are compared to NIR Landsat TM data in separate analyses of data information content and temporal resolution; the optical data are found to be better for both facies discrimination and obtaining synoptic glaciological information in mountainous regions. However, the Spitsbergen cloud cover is such that useful TM data may not necessarily be acquired in a given year; consequently SAR is the better sensor for obtaining guaranteed synoptic mass balance data for use in climate change studies, or for studying short-term events like glacier surges. These conclusions are shown to apply to the entire European Arctic sector except East Greenland, where the two sensors have similar temporal resolutions. Data from both sensors were integrated to provide an estimation of the synoptic mass balance of Nordenskiold Land for 1991/92; the results, which indicate an overall slightly negative mass balance, demonstrate that elevation is the principal factor governing glacier net mass balance in the region.

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This thesis presents a way to generate a Digital Terrain Model (dtm) from a Digital Surface Model (dsm) and multi spectral images (including the Near Infrared (nir) color band). An Artificial Neural Network (ann) is used to pre-classify the dsm and multi spectral images. This in turn is used to filter the dsm to a dtm. The use of an ann as a classifier provided good results. Additionally, the addition of the nir color band resulted in an improvement of the accuracy of the classifier. Using the classifier, a dtm was easily extracted without removing natural edges or height variations in the forests and cities. These challenges are handled with great satisfaction as compared to earlier methods.

<p>This project analyzes satellite images from 1976, 1985 and 2000 of Dutse, Jigawa state, in north-western Nigeria. The analyzed satellite images were used to determine land-use and vegetation changes that have occurred in the land-use from 1976 to 2000 will help recommend possible planning measures in order to protect the vegetation from further deterioration.</p><p>Studying land-use change in north-western Nigeria is essential for analyzing various ecological and developmental consequences over time. The north-western region of Nigeria is of great environmental and economic importance having land cover rich in agricultural production and livestock grazing. The increase of population over time has affected the land-use and hence agricultural and livestock production.</p><p>On completion of this project, the possible land use changes that have taken place in Dutse will be analyzed for future recommendation. The use of supervised classification and change detection of satellite images have produced an economic way to quantify different types of landuse and changes that has occurred over time.</p><p>The percentage difference in land-use between 1976 and 2000 was 37%, which is considered to be high land-use change within the period of study. The result in this project is being used to propose planning strategies that could help in planning sustainable land-use and diversity in Dutse.</p>

This thesis is on the estimation models for the daily global solar irradiation on a horizontal surface at the surface of the Earth. New approaches are developed and applied to 15 locations of Turkey and Germany. The main idea in developing the new models is to link the surface data to satellite imagery. Totally three new modeling approaches are developed and tested. Surface data of daily bright sunshine hours (s) and cloud index (n) values derived from satellite images are the main input parameters. In the first approach, monthly coefficients of Angstr&ouml / m linear relation between daily solar irradiation and daily bright sunshine hours are used to replace the clear sky irradiance calculations of HELIOSAT model. In the second approach new correlations are obtained between daily bright sunshine hours (s) and cloud index (n). Last model that is developed uses a new correlation expression between daily solar irradiation and daily data of s and n and this expression is derived using a physical consideration. The performances of the proposed models are tested against conventional methods (mainly, satellite-based HELIOSAT and ground-based linear Angstr&ouml / m-Prescott type). The results show that the use of sunshine duration together with the cloud index is quite satisfactory in the estimations of daily global solar irradiation. The accuracy of estimations of the combined models is considerably higher than the conventional approaches. Therefore, we propose to use the new approaches to estimate daily global irradiation whenever the data of bright sunshine hours is available for the location of interest or a nearby station. In addition, for a point on the earth surface, depending on the data in hand, suitable and most accurate models of estimations are proposed for that point.

Οι δορυφορικές εικόνες ASTER αποτελούν το πιο πρόσφατο προϊόν της διαστημικής τεχνολογίας, Έχει πολύ μεγάλη φασματική διακριτική ικανότητα σε σημείο που να χαρακτηρίζεται από αρκετούς επιστήμονες σαν ένα υπερφασματικό καταγραφικό σύστημα στο υπέρυθρο. Έτσι δίνονται νέες δυνατότητες για την ερμηνεία είτε ποιοτικά είτε ποσοτικά καλύψεων γης και φυσικών καταστάσεων της γήινης επιφάνειας, αφού οι προηγούμενοι δορυφόροι δεν είχαν αυτή τη δυνατότητα. Ο σκοπός είναι η περιβαλλοντική χαρτογράφηση του N. Λέσβου από δορυφορικές εικόνες ASTER προκειμένου να χαρτογραφηθούν οι φυσικοί πόροι και οι καλύψεις Γης. Έτσι θα μπορούμε να αξιολογήσουμε τις δυνατότητες και τις εφαρμογές που έχουν αυτά τα δεδομένα. Μετά τις διορθώσεις (αποζωνοποίηση, μετατροπή σε τιμές ενέργειας, κ.α.) η ταξινόμηση της δορυφορικής εικόνας μας επέτρεψε να διακρίνουμε τις παρακάτω κατηγορίες: καλλιέργειες/ ποώδη βλάστηση, δύο τύπους δάσους, αστική γη, υδάτινες επιφάνειες, σύννεφα και εντελώς γυμνό από βλάστηση έδαφος και να δημιουργήσουμε ένα θεματικό χάρτη. Εάν χρησιμοποιηθούν περισσότερα κανάλια και όχι μόνο 3, τότε θα γίνει δυνατή η χαρτογράφηση περισσότερων κατηγοριών μόνο που η ταυτοποίηση της κάθε κατηγορίας θα μπορεί να πραγματοποιηθεί μόνο με εργασίες πεδίου στο ύπαιθρο. / The ASTER satellite images are the most recent product of space technology , has very high spectral resolution to a point that is characterized by many scientists as a hyperspectral infrared recording system . So given new possibilities for interpretation either qualitatively or quantitatively land cover and physical conditions of the Earth's surface , having earlier satellites did not have that feature. The purpose is environmental mapping N. Lesbos from ASTER satellite images to map the natural resources and land cover . Thus we can evaluate the features and applications that have these data . After corrections ( apozonopoiisi , conversion to energy prices , etc. ) the classification of satellite imagery allowed us to distinguish the following categories : crops / herbaceous vegetation , two types of forest , urban land , water surfaces , clouds and completely devoid of vegetation area and create a thematic map . If you use more channels , not just three , then it will become possible to map more categories only the identification of each class can only be done with field work outdoors .

This project analyzes satellite images from 1976, 1985 and 2000 of Dutse, Jigawa state, in north-western Nigeria. The analyzed satellite images were used to determine land-use and vegetation changes that have occurred in the land-use from 1976 to 2000 will help recommend possible planning measures in order to protect the vegetation from further deterioration. Studying land-use change in north-western Nigeria is essential for analyzing various ecological and developmental consequences over time. The north-western region of Nigeria is of great environmental and economic importance having land cover rich in agricultural production and livestock grazing. The increase of population over time has affected the land-use and hence agricultural and livestock production. On completion of this project, the possible land use changes that have taken place in Dutse will be analyzed for future recommendation. The use of supervised classification and change detection of satellite images have produced an economic way to quantify different types of landuse and changes that has occurred over time. The percentage difference in land-use between 1976 and 2000 was 37%, which is considered to be high land-use change within the period of study. The result in this project is being used to propose planning strategies that could help in planning sustainable land-use and diversity in Dutse.

The aim of the study – improvement of on-going in Lithuania forest inventories based on satellite images and GIS databases. Specific objective of the study – to explore the possibilities of methods applied for the collection of information from satellite images and GIS databases and its processing in order to determine various Lithuanian forest characteristics, focusing on a variety of forest inventory schemes. 4 The goals of the study: 1. To discuss methodological assumptions for the use of satellite images and GIS database information to estimate various characteristics of the Lithuanian forests. 2. To investigate methodological assumptions for the application of two-phase sampling scheme based on medium-resolution satellite images for the estimation of Lithuanian forest characteristics. 3. To investigate the possibilities of application of medium-resolution satellite images on the basis of two-phase sampling scheme in stand-wise, mature stands and pre-harvesting forest inventories. 4. To investigate methodological decisions and application peculiarities of fast detection of changes in the forest using medium-resolution satellite images under Lithuanian conditions. Scientific novelty The development of methodological background for the use of medium-resolution satellite images and two-phase sampling-based schemes in Lithuanian forest inventory. The use of stand-wise forest inventory data as an auxiliary information together with medium-resolution satellite images in... [to full text] / Bendrasis darbo tikslas – Lietuvoje vykdomų miškų inventorizacijų tobulinimas kosminių nuotolinių tyrimų vaizdų bei GIS duomenų bazių pagrindu. Darbo konkretusis tikslas – ištirti kosminių nuotolinių tyrimų vaizdų ir GIS duomenų bazių informacijos, jos apdorojimo metodų galimybes nustatant įvairias Lietuvos miškų charakteristikas, orientuojantis į įvairias miško inventorizacijos schemas. Darbo uždaviniai: 1. Aptarti kosminių nuotolinių tyrimų vaizdų ir GIS duomenų bazių informacijos naudojimo vertinant įvairias Lietuvos miškų charakteristikas metodines prielaidas. 2. Ištirti dviejų fazių atrankos schemos taikymo vidutinės skiriamosios gebos kosminių vaizdų pagrindu vertinant įvairias Lietuvos miškų charakteristikas metodines prielaidas. 3. Ištirti dviejų fazių atrankos schema grindžiamo vidutinės skiriamosios gebos kosminių vaizdų taikymo sklypinėje, brandžių medynų bei prieškirtiminėje miškų inventorizacijose galimybes. 4. Ištirti operatyvaus pakitimų aptikimo miške, naudojant vidutinės skiriamosios gebos kosminius vaizdus, metodinius sprendimus bei jų taikymo Lietuvos sąlygomis ypatumus. Mokslinis naujumas Išvystyti vidutines skiriamosios gebos kosminių vaizdų ir dviejų fazių atranka grindžiamų vertinimo schemų naudojimo Lietuvos miškų inventorizacijoje metodiniai pagrindai. Sklypinės miškų inventorizacijos duomenų naudojimas kaip pagalbinė informacija kartu su vidutinės skiriamosios gebos kosminiais vaizdais dviejų fazių atrankos schemose vertinant miško charakteristikas... [toliau žr. visą tekstą]

Μετά τις διορθώσεις (αποζωνοποίηση, μετατροπή σε τιμές ενέργειας, κ.α.) η ταξινόμηση της δορυφορικής εικόνας μας επέτρεψε να διακρίνουμε τις 11 θεματικές κατηγορίες η ερμηνεία των οποίων προϋποθέτει εργασίες πεδίου. Εάν χρησιμοποιηθούν περισσότερα κανάλια και όχι μόνο 3, τότε θα γίνει δυνατή η χαρτογράφηση περισσότερων κατηγοριών μόνο που η ταυτοποίηση της κάθε κατηγορίας θα μπορεί να πραγματοποιηθεί πάλι μόνο με εργασίες πεδίου στο ύπαιθρο. / -

Οι δορυφορικές εικόνες ASTER αποτελούν το πιο πρόσφατο προϊόν της διαστημικής τεχνολογίας, Έχει πολύ μεγάλη φασματική διακριτική ικανότητα σε σημείο που να χαρακτηρίζεται από αρκετούς επιστήμονες σαν ένα υπερφασματικό καταγραφικό σύστημα στο υπέρυθρο. Έτσι δίνονται νέες δυνατότητες για την ερμηνεία είτε ποιοτικά είτε ποσοτικά καλύψεων γης και φυσικών καταστάσεων της γήινης επιφάνειας, αφού οι προηγούμενοι δορυφόροι. Ο σκοπός είναι η περιβαλλοντική χαρτογράφηση από δορυφορικές εικόνες ASTER προκειμένου να χαρτογραφηθούν οι φυσικοί πόροι και οι καλύψεις Γης. Έτσι θα μπορούμε να αξιολογήσουμε τις δυνατότητες και τις εφαρμογές που έχουν αυτά τα δεδομένα. Μετά τις διορθώσεις (αποζωνοποίηση, μετατροπή σε τιμές ενέργειας, κ.α.) η ταξινόμηση της δορυφορικής εικόνας μας επέτρεψε χαρτογραφήσουμε θεματικές τάξεις (βλάστηση, κ.α.) και να δημιουργήσουμε ένα θεματικό χάρτη. Η ταυτοποίηση της κάθε κατηγορίας μπορεί να πραγματοποιηθεί μόνο με εργασίες πεδίου στο ύπαιθρο. / Αster satellite images are the latest product space technology.It has very high spectral resolution in a place that is characterized as a hyperspectral infrared recording system.Identification of each class can only work with PAE.