Mountain glaciers are expected to be the greatest contributor to sea level rise over the next century. Glaciers provide a good indicator of global climate and how to monitor their change is an increasingly important issue for climate science and for sea level rise forecasts. However, there has been little direct measurement of glacier volume change in New Zealand. This study explores the use of remotely sensed data for measuring glacier volume change from 1965 to 2006. Digital photogrammetric methods were used to extract topographic data of the Tasman Glacier from aerial photography and ASTER imagery for the years 1965, 1986, 2002 and 2006. SRTM C band data from 2000 were also analysed. Data were compared to an existing digital elvation model produced from the New Zealand Digital Topographic Database to test for their reliability. Using regression analysis, the data were filtered and points representing rock were used to correct points on the glacier ice for vertical bias. The quality of the data extracted from the aerial photography was good on rock and debris covered ice, but poor on snow. The data extracted from ASTER was much more reliable on snow in the upper glacier than the aerial photography, but was very poor in the lower debris covered region of the glacier. While the quality of the SRTM data is very high, there is a second order distortion present in the data that is evident over elevation differences. However, the overall mean difference of the SRTM rock from TOPODATA is close to zero. An overall trend could be seen in the data between dates. However, the 2006 ASTER data proved unreliable on the debris covered section of the glacier. Total volume change is therefore calculated for the period between 1965 and 2002. The data show a loss of 3:4km³ or 0:092km³ per year, an estimated 6% of the total ice in New Zealand. This is compared to estimates using the annual end of summer snowline survey between 1977 and 2005 of 1:78 km³, or 0:064km³ per year. The spatial resolution of ASTER makes high temporal resolution monitoring of volume change unlikely for the New Zealand glaciers. The infrequency of aerial photography, the high cost and vast time involved in extracting good quality elevation data from aerial photography makes it impractical for monitoring glacier volume change remotely. However, SRTM and other radar sensors may provide a better solution, as the data do not rely heavily on user processing.

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. 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 μάς επέτρεψε να διακρίνουμε τις παρακάτω κατηγορίες: καλλιέργειες, ποώδη βλάστηση, δάσος, 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. / ASTER satellite pictures constitute the most recent product of spatial technology. With high spectral judgmatic ability, it is characterized by many scientists as a hyperspectral recording system in infra red. Thus, new possibilities for qualitatively or quantitatively of interpretation of ground cover is provided. Our aim is the environmental mapping of Lesvos perfecture from ASTER satellite pictures so as to chart the natural resources and the Ground cover. In this way we may be able to evaluate the possibilities and the applications that those data have. After the corrections (transformation in prices of energy etc.) the classification of satellite pictures allowed us to distinguish between the categories below: cultures, underbrush vegetation, forests, urban ground, aquatic surfaces, clouds and completely naked from vegetation ground and we created one thematic map. If we are to use more than 3 channels, then the mapping of more categories will become possible, given that the identification of each category might be realised only with countryside field work.

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 του N. Ηλείας 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 (πχ κοίτη ποταμού που καταλήγει στην τεχνητή λίμνη του Πηνειού) 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. / -

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. Ο σκοπός είναι η περιβαλλοντική χαρτογράφηση της θαλάσσιας ζώνης από δορυφορικές εικόνες ASTER προκειμένου να χαρτογραφηθούν μεταβολές στην ανακλαστικότητα που μπορεί να οφείλονται είτε σε διάφορα στο βάθος της θάλασσας είτε σε φαινόμενα ευτροφισμού, ρύπανσης και άλλα. Μετά τις διορθώσεις (αποζωνοποίηση, μετατροπή σε τιμές ενέργειας, κ.α.) η ταξινόμηση της δορυφορικής εικόνας μας επέτρεψε να διακρίνουμε ζώνες διαφορετικής ανακλαστικότητας στο θαλάσσιο περιβάλλον και να δημιουργήσουμε ένα θεματικό χάρτη, ταυτοποίηση του οποίου απαιτεί εργασίες υπαίθρου. / -

Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2005. / 81 Leaves printed on single pages i-xi, preliminary pages and numbered pages 1- 70. Includes bibliography, list of tables and list of figures. / Digitized at 300 dpi color PDF format (OCR), using KODAK i 1220 PLUS scanner. / ENGLISH ABSTRACT: Geological field mapping is often limited by logistical and cost constraints as well as the scope and extent of observations possible using ground-based mapping. Remote sensing offers, among others, the advantages of an increased spectral range for observations and a regional perspective of areas under observation. This study aimed to determine the accuracy of a collection of image classification techniques when applied to ASTER reflectance data. Band rationing, the Crosta Technique, Constrained Energy Minimization, Spectral Correlation Mapping and the Maximum Likelihood Classifier were evaluated for their efficiency in detecting and discriminating between greenstone and granitoid material. The study area was the Archaean Barberton Greenstone Belt in the eastern Mpumalanga Province, South Africa. ASTER reflectance imagery was acquired and pre-processed. Training and reference data was extracted from the image through visual inspection and expert knowledge. The training data was used in conjunction with USGS mineral spectra to train the five classification algorithms using the ERDAS's software package. This resulted in abundance images for the target materials specified by the training data. The Maximum Likelihood Classifier produced a classified thematic map. The reference data was used to perform a rigorous classification accuracy assessment procedure. All abundance images were thresholded to varying levels, obtaining accuracy statistics at every level. In so doing, threshold levels could be defined for every abundance image in such a way that the reliability of the classification was optimized. For each abundance image, as well as for the output map of the Maximum Likelihood Classifier, user's- and producer's accuracies as well as kappa statistics were derived and used as comparative measures of efficiency between the five techniques. This information was also used to assess the spectral separability of the target materials. The Maximum Likelihood Classifier outperformed the other techniques significantly, achieving an overall classification accuracy of 81.1% and an overall kappa value of 0.748. Greenstone rocks were accurately discriminated from granitoid rocks with accuracies between 72.9% and 98.5%, while granitoid rocks showed very poor ability to be accurately distinguished from each other. The main recommendations from this study are that thermal infrared and gamma-ray data be considered, together with better vegetation masking and an investigation into object orientated techniques. / AFRIKAANSE OPSOMMING: Geologiese veldkartering word algemeen beperk deur logistiese en koste-verwante faktore, sowel as die beperkte bestek waartoe waarnemings met veld-gebasseerde tegnieke gemaak kan word. Afstandswaarneming bied, onder andere, 'n vergrote spekrale omvang vir waarnemings en 'n regionale perspektief van die area wat bestudeer word. Hierdie studie was gemik daarop om die akkuraatheid van 'n versameling beeld-klassifikasie tegnieke, toegepas op ASTER data, te bepaal. Bandverhoudings, die Crosta Tegniek, "Constrained Energy Minimization", Spektrale Korrellasie Kartering, en Maksimum Waarskynlikheid Klassifikasie is evalueer op grond van hul vermoë om groensteen en granitoied-rotse op te spoor en tussen hulle te onderskei. Die studiegebied was die Argalese Barberton Groensteengordel in die oostelike Mpumalanga Provinsie in Suid Afrika. 'n ASTER refleksie beeld is verkry, waarop voorverwerking uitgevoer is. Opleidings- en verwysingsdata is van die beeld verkry deur visuele inspeksie en vakkundige kennis. Die opleidingsdata is saam met VSGO mineraalspektra gebruik om die vyf klassifikasie algoritmes met behulp van die ERDAS sagteware pakket op te lei. Die resultaat was volopheidsbeelde vir die teikenmateriale gespesifiseer in die opleidingsdata. Die Maksimum Waarskynlikheid algoritme het 'n geklassifiseerde tematiese beeld gelewer. Met behulp van die verwysingsdata is 'n streng akkuraatheidstoetsing prosedure uitgevoer. Vir alle volopheidsbeelde is 'n reeks drempelwaardes gestel, en by elke drempelwaarde is akkuraatheidsstatistieke afgelei. Op hierdie manier kon 'n drempelwaarde vir elke volopheidsbeeld vasgestel word sodat die drempelwaarde die betroubaarheid van die klassifikasie optimeer. Vir elke volopheidsbeeld, asook vir die tematiese kaart verkry van die Maksimum Waarskynlikheid klassifikasie, is gebruikers- en produsent-akkuraathede en kappa statistieke bereken. Hierdie waardes is gebruik as vergelykende maatstawwe van akkuraatheid tussen die vyf tegnieke, asook van die spektrale skeibaarheid van die onderskeie teikenmateriale. Die Maksimum Waarskynlikheid klassifikasie het die beste resultate gelewer, met 'n algehele klassifikasie akkuraatheid van 81.1%, en 'n gemiddelde kappa waarde van 0.748. Groensteenrotse kon met hoë akkuraathede van tussen 72.9% en 98.5% van granitoiedrotse onderskei word, terwyl granitoiedrotse 'n swak vermoë getoon het om van mekaar onderskei te word. Die belangrikste aanbevelings vanuit hierdie studie is dat termiese uitstralingdata asook gamma-straal data geimplimenteer word. Beter verwydering van plantegroei en 'n studie na die lewensvatbaarheid van objekgeorienteerde metodes word ook aanbeveel.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: South Africa is ranked amongst the top ten for wine production internationally. Viticulture contributes immensely to the economy, which justifies research into the pathogens that may negatively affect wine production. Aster Yellows phytoplasma was reported in South African vineyards in 2010 and has since been an ongoing problem for grape farmers in affected areas. Throughout the world, phytoplasma diseases such as Grapevine Yellows have caused detrimental effects on the vines, often resulting in death. The limited knowledge on prevention and control of the pathogen can be attributed to the lack of full understanding of the epidemiology and accurate diagnosis. The aim of this study was to determine the spatial distribution of Aster Yellows phytoplasma in individual grapevines and to record a possible temporal or seasonal distribution. The recovery phenotype phenomenon was encountered during the study and surveys were conducted in order to determine whether recovery was permanent. In order to perform the studies, a reliable assay to accurately detect the pathogen in grapevines was required. A comparison between three assays was completed in furtherance of deciding which to use for the further experimentation. The three assays included a nested PCR utilizing universal primers, a Real-Time PCR using Syto9 as a double stranded DNA specific dye and a Real- Time PCR with a TaqMan® probe using an identical dilution series. Of the three assays tested, the nested PCR proved to be the most sensitive diagnostic procedure, detecting Aster Yellows phytoplasma in very low titers and was thus used for diagnostics in further experiments. In order to determine the spatial patterns of Aster yellows phytoplasma infection, leaf, petiole, trunk, root and cane samples were taken from three whole grapevine plants. Phloem scrapings obtained from the cane samples yielded more positive results in comparison to the other parts of the plant tested. Not only do phytoplasmas display an erratic spatial distribution, but also have a tendency to change over time. Thirty symptomatic grapevines were sampled over one and a half growing seasons, with results concluding that February yielded the most positive diagnoses. Fifty plants that had been previously pruned back and no longer displayed symptoms were also sampled in 2013 and 2014, and all yielded negative results over both years. This study contributes to comprehension of Aster Yellows phytoplasma epidemiology and ultimately the advancement of accurate diagnosis. / AFRIKAANSE OPSOMMING: Suid-Afrika is internasionaal geposisioneer onder die top tien vir die produksie van wyn. Wingerd dra geweldig by tot die ekonomie, wat navorsing oor die patogene wat wynporduksie negatief beïnvloed, regverdig. Aster Yellows phytoplasmais in 2010 gerapporteer in Suid-Afrikaanse wingerde en is sedertdien 'n deurlopende probleem vir druiweboere in geaffekteerde gebiede. Dwarsdeur die wêreld, het fitoplasma siektes soos Grapevine Yellows ‘n nadelige uitwerking op wingerde, wat dikwels lei tot plantsterftes. Die beperkte kennis oor die voorkoming en beheer van die patogeen kan toegeskryf word aan die gebrek aan begrip van die epidemiologie en akkurate diagnose . Die doel van hierdie studie was om die ruimtelike verspreiding van Aster geel fitoplasma in individuele wingerdstokke te bepaal en 'n moontlike tydelike of seisoenale verspreiding aan te teken. Die herstel-fenotipe verskynsel is tydens die studie teëgekom en opnames is uitgevoer ten einde te bepaal of die herstel permanent was. Ten einde die studie uit te voer , is 'n betroubare toets vereis om die patogeen in wingerde akkuraat te spoor. : Drie toetse is vergelyk (en geëvalueer) vir hulle geskikthed vir gebruik in die studie. Die drie toetse het ingesluit 'n geneste PKR wat gebruik maak van universele primers, 'n in-tydse PKR (real-time PCR) wat Syto9 gebruik as 'n dubbelstring DNS spesifieke kleurstof, en 'n in-tydse PKR met 'n TaqMan® peiler, en is vergelyk met behulp van 'n identiese vedunnings reeks. Van die drie toetse , is die geneste PCR bewys om die mees sensitiewe diagnostiese prosedure te wees , en kon Aster geel fitoplasma in baie lae titers opspoor en is dus gebruik vir die diagnose in verdere eksperimente. Ten einde die ruimtelike patrone van Aster geel fitoplasma infeksie te bepaal, is blaar, blaarsteel, stam, wortel en loot monsters van drie volle wingerdstokke geneem. Floëem skraapsels verkry uit die loot monsters het meer positiewe resultate opgelewer in vergelyking met die ander dele van die plant. Nie net vertoon phytoplasmas 'n wisselvallige ruimtelike verspreiding nie, maar het ook 'n neiging om te verander met verloop van tyd. Dertig simptomaties wingerdstokke is versamel oor een en 'n half groeiseisoene,en die resultate het gewys dat Februarie die meeste positiewe diagnoses het. Monsters is versamel in 2013 en 2014 van vyftig plante wat voorheen teruggesnoei is en nie meer simptome vertoon nie, en alle monsters het negatiewe resultate opgelewer oor beide jare. Hierdie studie dra by tot begrip van Aster geel fitoplasma epidemiologie en uiteindelik die bevordering van akkurate diagnose.

Com o surgimento de novos métodos de extração de dados altimétricos no mercado de geotecnologias a escolha da melhor técnica é um problema que preocupa a maioria dos usuários. Como nenhum dado está isento de erros faz-se necessário propor método que faça uso dessa diversidade de informações minimizando-se o erro. A Colocação por Mínimos Quadrados é uma técnica que permite a integração de dados diferentes em tipo e precisão. Assim, a presente dissertação teve como objetivo a determinação e avaliação de um novo Modelo Digital de Elevação, denominado MDE Híbrido, a partir de dados altimétricos obtidos através de diferentes técnicas: fotogrametria (curvas de nível extraídas de carta 1:50.000), estereoscopia em imagens de um sensor orbital (ASTER) e interferometria de radar (SRTM). Foram selecionadas três áreas no município de Porto Alegre/RS, que apresentam diferentes tipos de relevo: plano, misto e acidentado. Nessas áreas foram obtidos os MDEs a partir de curvas de nível, imagens ASTER e do SRTM com resoluções de 30m, 15m e 90m respectivamente. Uma avaliação pontual foi realizada nos três dados onde pode-se observar que para cada área de estudo um diferente dado apresentou menor Erro Médio Quadrático. Estes três dados foram então integrados utilizando-se a Colocação por Mínimos Quadrados e resolução de 15m. Após avaliação, o MDE Híbrido na Área Plana apresentou acurácia altimétrica igual a 3,493m e na Área Mista o valor de 4,763m o que atende aos requisitos da Classe A do PEC (Padrão de Exatidão Cartográfico) na escala 1:25.000. Já na Área Acidentada o valor encontrado foi de 8,66m atendendo os requisitos da Classe A do PEC na escala 1:50.000. Os resultados práticos alcançados nesta pesquisa mostraram que os dados altimétricos com diferentes resoluções espaciais podem ser integrados, desde que se tenha conhecimento das suas precisões. A resolução espacial de um determinado dado não está relacionada com a precisão deste dado. / With the appearance of new methods of altimetric data extraction, the choice for the best technique is a problem that concerns the majority of users. As no data is error free, it is necessary to propose a methodology that may use this diversity of information as well as minimize errors which arise from each data. The Least-Squares Collocation (CMQ) is a technique that allows the integration of different data according to type and precision. Thus, this paper aimed at determining and evaluating a new Digital Elevation Model called Hybrid MDE, which was obtained through the integration of data from different techniques: Photogrammetry (level curves extracted from maps, Stereoscopy (ASTER) and Interferometry (SRTM). To evaluate the efficiency of this methodology, we selected three areas in the city of Porto Alegre/RS, which showed different types of relief: plain, mixed and rough. In these areas, the MDEs were generated from level curves and ASTER images, which had a resolution of 30 m and 15m respectively; we also included the SRTM data, which show a resolution of 90 m. These three data were then integrated, using the CMQ, and determining a new model with a final resolution of 15 m, which was called Hybrid MDE. Lastly, we realized an evaluation, in which the Hybrid MDE in the Plain Area showed an altimetric accuracy equal to 3,493 m and in the Mixed Area 4, 763, which follows the Class A requisites of the Standard of Cartographic Exactness (PEC) in the scale of 1:25.000. In the Rough Area, the value found was 8, 66 m , following the Class A requisites for PEC in the scale of 1:50.000. The practical results reached in this research show that altimetric data with different spatial resolutions may be integrated, as long as we are aware of its precision.

As técnicas de sensoriamento remoto têm se mostrado fundamentais como ferramenta auxiliar no mapeamento geológico básico. O avanço tecnológico gerado pelos novos sensores permite o desenvolvimento de técnicas mais apuradas na integração de dados litológicos e estruturais de várias fontes. Este trabalho buscou avaliar a potencialidade das imagens do sensor ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) para identificação dos diferentes litotipos da área do Cerro Chato, em especial as unidades vulcânicas e hipabissais relacionadas. O Cerro Chato é caracterizado como uma feição geomorfológica situada à cerca de 15 km ao norte do município de Herval, na microrregião denominada Serra do Sudeste na porção sudeste do estado do Rio Grande do Sul. É constituído principalmente por uma seqüência de rochas efusivas e piroclásticas de composição riolítica relacionada a sistemas do tipo alta-sílica, vinculadas ao magmatismo granítico tardio do Batólito Pelotas. O objetivo deste trabalho foi testar e avaliar diversas técnicas de geoprocessamento buscando a diferenciação litológica, a identificação de alvos e a definição de morfoestruturas da área do Cerro Chato. O processamento utilizando a técnica de Transformação por Componentes Principais forneceu os melhores resultados realçando diferenças entre as rochas vulcânicas e hipabissais e as rochas encaixantes. Foram selecionadas as CP2 das imagens CP's 2, 3 e 5 na geração de uma composição colorida que permitiu delimitar três principais domínios de ocorrências das rochas de origem vulcânica no Cerro Chato. / The remote sensing techniques have been a very important and auxiliary tool to basic geological mapping. The new orbital sensors carried out a technologic increment that possibility the development of refined methods applied in the integration with diverse geologic data as petrology and structural. In this work were utilized images obtained from the ASTER sensor (Advanced Spaceborne Thermal Emission and Reflection Radiometer) to identify the lithologies in the Cerro Chato area, giving emphasis to the volcanic and hypabissal units. The Cerro Chato can be characterized as geomorphologic feature situated about 15 km to north of Herval town, in the Southeast Sierra micro region of the Rio Grande do Sul state, southernmost Brazil. It is constituted mainly by an effusive and pyroclastic rocks sequence of rhyolitic composition related to high silica systems, which magma has been associated to the younger granitic magmastim of the Pelotas Batholith. The main objective of this work was to test and evaluate diverse techniques of geoprocessment to try identifying different lithologic units and morphologic structures in the Cerro Chato area. The selective principal component analysis technique was used in the digital image processing, because it provided the best results enhancing the existent spectral differences between volcanic and country rocks. In this processing were selected the PC's2 images of the PC's 2, 3, and 5 to generated a color composite image that permitted the individualization of three main dominions of volcanic rocks in the Cerro Chato.

No presente estudo foram empregadas diferentes técnicas de sensoriamento remoto com vistas a sua utilização na exploração e estudo de depósitos minerais, com foco na redução de tempo e custos em programas de geologia e exploração mineral. A área de estudo está situada na porção centro-sul do Estado do Rio Grande do Sul, no município de Caçapava do Sul, na localidade de Minas do Camaquã, a aproximadamente 350 km da capital do estado, Porto Alegre, com acesso final através da BR- e estradas vicinais. As coordenadas de referência da Mina Uruguai são 30°54’34” Sul e 53°26’37” Oeste. Dados multiespectrais do sensor ASTER pré-processados (calibração radiométrica e correção atmosférica), na faixa do visível, infravermelho próximo e de ondas curtas (350 a 2500 nm), em conjunto com análises espectrais de amostras de rochas sedimentares eopaleozoicas foram utilizados com vistas ao mapeamento espectral da alteração hidrotermal associada às ocorrências de cobre na Mina Uruguai (Minas do Camaquã/RS). As leituras foram efetuadas em um espectrorradiômetro portátil ASD FieldSpec-3 High-Resolution e a interpretação mineralógica das assinaturas espectrais foi efetuada com o apoio do software The Spectral Geologist (TSG™Pro). O algoritmo Spectral Angle Mapper (SAM) foi selecionado para o mapeamento espectral da cena do sensor ASTER. Foram identificados caulinita + ilita (fengita + muscovita) + clorita (férrica e ferromagnesiana) + hematita + goetita, paragênese mineral que, associada a outras características observadas na Mina Uruguai, é consistente com alteração hidrotermal sob condições epitermais de baixo enxofre. Como resultado do mapeamento espectral, foram reconhecidas zonas argilizadas (ilita) e sericitizadas. O tipo de alteração, com ocorrência restrita a apenas alguns metros a partir dos filões, diferentemente do que ocorre, por exemplo, nos depósitos de cobre pórfiro, onde a alteração hidrotermal é intensa e pervasiva, torna mais complexa sua identificação na cena ASTER. A cobertura vegetal identificada na região também é elemento interferente na aplicação da técnica, a qual deve ser utilizada de forma combinada à espectroscopia de reflectância, para resultados mais efetivos em áreas com condições fisiográficas pouco favoráveis (clima úmido, com cobertura vegetal e alteração intempérica). / The present study applied different remote sensing techniques to evaluate its use in the exploration and study of mineral resources, focusing on the reduction of time and costs of geology and mineral exploration programs. The study area is located in the south central portion of the state of Rio Grande do Sul, in the municipality of Caçapava do Sul, in Minas do Camaquã, about 350 km from the state capital, Porto Alegre, with last access through BR -153 and country roads. The reference coordinates of Mina Uruguay are 30°54'34" South and 53°26'37" West. ASTER multispectral data preprocessed (radiometric calibration and atmospheric correction) in the visible, near infrared and shortwave infrared (350 to 2500 nm), in conjunction with eopaleozoicas sedimentary rock samples spectral analyzes, were used to spectral mapping of hydrothermal alteration associated with copper occurrences in Mina Uruguay (Minas Camaquã / RS). Spectral analysis were performed on ASD FieldSpec-3 High-Resolution portable spectroradiometer and the spectral signatures mineralogical interpretation was done in The Spectral Geologist (TSG ™ Pro) software. The algorithm Spectral Angle Mapper (SAM) was selected for the spectral mapping of ASTER scene. It was identified mineral paragenesis consists of kaolinite + illite (phengite + muscovite) + chlorite (ferric and ferromagnesiana) + hematite + goethite, which, combined with other characteristics observed in Mina Uruguay, is consistent with low sulphidation epithermal hydrothermal alteration. As a result of spectral mapping, it was also identified areas with illite and sericite. The kind of alteration, with occurrence restricted to just a few meters from the veins, unlike what happens, for example, deposits of porphyry copper, where the hydrothermal alteration is intense and pervasive, becomes more complex your recognition in ASTER scene. The vegetation identified in the region is also intervening material on technical application, which must be used in combination with reflectance spectroscopy for more effective results in areas with unfavorable physiographic conditions (humid climate with vegetation and weathering).

Com o surgimento de novos métodos de extração de dados altimétricos no mercado de geotecnologias a escolha da melhor técnica é um problema que preocupa a maioria dos usuários. Como nenhum dado está isento de erros faz-se necessário propor método que faça uso dessa diversidade de informações minimizando-se o erro. A Colocação por Mínimos Quadrados é uma técnica que permite a integração de dados diferentes em tipo e precisão. Assim, a presente dissertação teve como objetivo a determinação e avaliação de um novo Modelo Digital de Elevação, denominado MDE Híbrido, a partir de dados altimétricos obtidos através de diferentes técnicas: fotogrametria (curvas de nível extraídas de carta 1:50.000), estereoscopia em imagens de um sensor orbital (ASTER) e interferometria de radar (SRTM). Foram selecionadas três áreas no município de Porto Alegre/RS, que apresentam diferentes tipos de relevo: plano, misto e acidentado. Nessas áreas foram obtidos os MDEs a partir de curvas de nível, imagens ASTER e do SRTM com resoluções de 30m, 15m e 90m respectivamente. Uma avaliação pontual foi realizada nos três dados onde pode-se observar que para cada área de estudo um diferente dado apresentou menor Erro Médio Quadrático. Estes três dados foram então integrados utilizando-se a Colocação por Mínimos Quadrados e resolução de 15m. Após avaliação, o MDE Híbrido na Área Plana apresentou acurácia altimétrica igual a 3,493m e na Área Mista o valor de 4,763m o que atende aos requisitos da Classe A do PEC (Padrão de Exatidão Cartográfico) na escala 1:25.000. Já na Área Acidentada o valor encontrado foi de 8,66m atendendo os requisitos da Classe A do PEC na escala 1:50.000. Os resultados práticos alcançados nesta pesquisa mostraram que os dados altimétricos com diferentes resoluções espaciais podem ser integrados, desde que se tenha conhecimento das suas precisões. A resolução espacial de um determinado dado não está relacionada com a precisão deste dado. / With the appearance of new methods of altimetric data extraction, the choice for the best technique is a problem that concerns the majority of users. As no data is error free, it is necessary to propose a methodology that may use this diversity of information as well as minimize errors which arise from each data. The Least-Squares Collocation (CMQ) is a technique that allows the integration of different data according to type and precision. Thus, this paper aimed at determining and evaluating a new Digital Elevation Model called Hybrid MDE, which was obtained through the integration of data from different techniques: Photogrammetry (level curves extracted from maps, Stereoscopy (ASTER) and Interferometry (SRTM). To evaluate the efficiency of this methodology, we selected three areas in the city of Porto Alegre/RS, which showed different types of relief: plain, mixed and rough. In these areas, the MDEs were generated from level curves and ASTER images, which had a resolution of 30 m and 15m respectively; we also included the SRTM data, which show a resolution of 90 m. These three data were then integrated, using the CMQ, and determining a new model with a final resolution of 15 m, which was called Hybrid MDE. Lastly, we realized an evaluation, in which the Hybrid MDE in the Plain Area showed an altimetric accuracy equal to 3,493 m and in the Mixed Area 4, 763, which follows the Class A requisites of the Standard of Cartographic Exactness (PEC) in the scale of 1:25.000. In the Rough Area, the value found was 8, 66 m , following the Class A requisites for PEC in the scale of 1:50.000. The practical results reached in this research show that altimetric data with different spatial resolutions may be integrated, as long as we are aware of its precision.