Cloud top height plays an important roll in the energy budget and is also important for aviation. This thesis concerns the quality control of cloud top height (CTH) retrievals. The approach for quality controlling retrieved CTH has been using the forward simulating software RTTOV. An error estimation function has been developed as well as an investigation to what simplifications can be done regarding the forward simulations for CTH purposes at SMHI. The purpose of the error estimation function is to validate CTH output from CTH retrieval algorithms by giving a rough error estimate of the retrieved CTH compared to what forward simulations predict. For simplifying the forward simulations the most promising results have been shown for lower clouds. Further testing is still of interest and for future work suggestions are provided regarding the error estimation function as well as for simplifying the forward simulations.

The need to monitor geophysical properties of first year ice (FYI) in the Arctic is increasing as this type of sea ice becomes more prevalent. One such method of monitoring the Arctic is the use of electromagnetic remote sensing techniques. These methods determine dielectric properties of the illuminated sea ice by interpreting how the electromagnetic waves interact within the medium. In the literature, there are empirical formulas relating these dielectric properties to the geophysical properties of the sea ice. The contributions of this research are the development and testing of a surface based active microwave remote sensor to monitor sea ice growth in the winter through the reconstruction of the time series complex permittivity profile of FYI. / October 2017

Approved for public release; distribution is unlimited / NOAA-7 AVHRR data from April 1982 and 1983 were used to perform a global scale analysis of aerosol particle characteristics. Several improvements were incorporated into an AVHRR multichannel satellite data technique developed by Pfeil (1986). This included better cloud and sunglint discrimination, removal of Rayleigh radiance and accounting for ozone absorption. The characteristics analyzed were optical depth and Aerosol Particle Size Index (S₁₂). S₁₂ provides the slope of the aerosol particle size distribution curve. Both of these parameters were evaluated during several naturally occurring events, foremost of which were the 1982 El Chicon eruption and the 1982-1983 El Nino-Southern Oscillation event. The results provided evidence that a significant amount of aerosol particles over marine regions are from land-derived sources. However, the results also provided evidence that some marine aerosol particles may be of biogenic origins, / http://archive.org/details/globalscaleestim00fros / Lieutenant, United States Navy

Master of Arts / Department of Geography / Douglas G. Goodin / The Chobe River Basin (CRB) is a flood-dependent ecosystem that relies on seasonal floods from the Zambezi and Linyanti Rivers. These flood pulses provide water for the flood recession agriculture in the region, water for the fishing grounds around Lake Liambezi, and nutrients for the vegetation in the CRB. Recent years have shown an increase in the magnitude of flooding, which could have consequences on the region’s biodiversity and the people living in the CRB. The goal of this study is to develop a classification framework based on a training library and time-windows to use in classifying the extent of flooding in the CRB. MODIS MOD09A1 satellite imagery served as the satellite imagery. Bands one through seven were converted into the tasseled cap transformation to serve as the feature selection. The study period, from February to July, is broken down into three time-windows. The time-windows are used because the land covers in the CRB go through significant spectral changes during the study period and the three time-windows seek to improve the classification accuracy. The classification methods include maximum likelihood classifier (MLC), decision trees (DT), and support vector machines (SVMs). The results show that DT and SVMs provide the highest overall accuracy and kappa values over MLC. Classification using the time-window method was statistically significant when comparing kappa values and visually, images classified using the correct training library for a time-window displayed higher agreement with the reference data. Flooding extent was high for 2014 but low in 2015 and 2016, indicating a decreasing trend. DTs provided better inundation maximums compared to SVMs and therefore is the reason that DT are the best classification technique. The results will provide planners with information regarding the extent of flooding in the CRB and where waterborne diseases occur in the region. A new classification technique is also developed for the remote sensing literature.

Satellite measurements of volcano deformation have the potential to illuminate a wide range of volcanic processes and have provided us with the first opportunity to investigate volcano deformation as an arc-scale process. This thesis presents the results of an Interferometric Synthetic Aperture Radar (InSAR) survey of the Central American Volcanic Arc between 2007 and 2010. My measurements confirm a statistically significant absence of magmatic deformation in Central America relative to other well-studied volcanic arcs. I estimate a minimum detection threshold for deformation at 20 of the arc’s 26 active volcanoes using time series analysis of interferometric phase. I find that the majority (∼80%) of literature measurements of volcano deformation made at other arcs would have been possible with the average magnitude of noise in Central American volcanoes. The absence of measurable magmatic deformation in Central America may therefore be due to factors that limit the geodetic expression of magma movement, including the deep pooling of basalts and high parental melt volatile content. The quantification of measurement uncertainty also allows me to use the lack of deformation at specific erupting volcanoes to make order of magnitude estimations of the minimum depth for magma storage that would not result in measurable deformation. I present measurements and interpretation of non-magmatic deformation associated with edifice development at two Central American volcanoes: Arenal, Costa Rica and Santiaguito, Guatemala. At Arenal, I measure apparently steady slip (∼7 cm/yr) on the volcano’s western flanks, which I attribute to gravity-driven slip on the boundary between lavas emplaced over the past 50 years and older tephras and paleosols. At Santiaguito, I demonstrate the measurement of large-scale (∼10-200 m) topographic change from a small set of large baseline interferograms. Measurements of post-2000 lava fields allow me to estimate extrusion rate, map changes to flow morphology and make simultaneous measurements of lava flow thickness and subsidence rate.

Fire activity, in terms of intensity, frequency, and total area burned, is expected to increase with a changing climate. A challenge for landscape-level assessment of fire effects, often termed burn severity, is that current remote sensing assessments provide very little information regarding tree/vegetation physiological performance and recovery, limiting our understanding of fire effects on ecosystem services such as carbon storage/cycling. In this paper, we evaluated whether spectral indices common in vegetation stress and burn severity assessments could accurately quantify post-fire physiological performance (indicated by net photosynthesis and crown scorch) of two seedling species, Larix occidentalis and Pinus contorta. Seedlings were subjected to increasing fire radiative energy density (FRED) doses through a series of controlled laboratory surface fires. Mortality, physiology, and spectral reflectance were assessed for a month following the fires, and then again at one year post-fire. The differenced Normalized Difference Vegetation Index (dNDVI) spectral index outperformed other spectral indices used for vegetation stress and burn severity characterization in regard to leaf net photosynthesis quantification, indicating that landscape-level quantification of tree physiology may be possible. Additionally, the survival of the majority of seedlings in the low and moderate FRED doses indicates that fire-induced mortality is more complex than the currently accepted binary scenario, where trees survive with no impacts below a certain temperature and duration threshold, and mortality occurs above the threshold.

Approved for public release; distribution is unlimited / Future underwater missions will require data transmission via satellite. In particular, the Office of Naval Research (ONR) is interested in experimenting with communications using the GOES satellite system, which is government owned. Unfortunately, communication antennas must point to specific satellites in this system and thus underwater vehicles must steer a specific course on the surface during the communication process. While surfaced, underwater vehicles are subject to wind and wave disturbances and it has been suggested that control using differential thrust from propellers may provide advantages. This thesis covers efforts to create and test such a steering autopilot based on the use of the ARIES AUV and differing the voltage supplied to each propeller. It is planned to use the ARIES in an ocean experiment to test this satellite communication capability. This control is embedded in the control of ARIES during extended pop up maneuvers for GPS navigational fixes. When surfaced, not only are navigational fixes obtained, but also data packets are communicated to a command center. / Lieutenant, United States Navy

<p> Passive longwave infrared radiometric satellite-based retrievals of sea surface temperature (SST) at instrument nadir are investigated for cold bias caused by unscreened optically-thin cirrus (OTC) clouds (cloud optical depth &le; 0.3; COD). Level 2 split-window SST retrievals over tropical oceans (30&deg; S - 30&deg; N) from Moderate Resolution Imaging Spectroradiometer (MODIS) radiances collected aboard the NASA Aqua satellite (Aqua-MODIS) are collocated with cloud profiles from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument, mounted on the independent NASA CALIPSO satellite. OTC are present in approximately 25% of tropical quality-assured (QA) Aqua-MODIS Level-2 data, representing over 99% of all contaminating cirrus found. This results in cold-biased SST retrievals using either split- (MODIS, AVHRR and VIIRS) or triple-window (AVHRR and VIIRS only) retrieval methods. SST retrievals are modeled based on operational algorithms using radiative transfer model simulations conducted with a hypothetical 1.5 km thick OTC cloud placed incrementally from 10.0 - 18.0 km above mean sea level for cloud optical depths (COD) between 0.0 - 0.3. Corresponding cold bias estimates for each sensor are estimated using relative Aqua-MODIS cloud contamination frequencies as a function of cloud top height and COD (assuming them consistent across each platform) integrated within each corresponding modeled cold bias matrix. Split-window relative OTC cold biases, for any single observation, range from 0.40&deg; - 0.49&deg; C for the three sensors, with an absolute (bulk mean) bias between 0.10&deg; - 0.13&deg; C. Triple-window retrievals are more resilient, ranging from 0.03&deg; - 0.04&deg; C relative and 0.11&deg; - 0.16&deg; C absolute. Cold biases are constant across the Pacific and Indian Ocean domains. Absolute bias is smaller over the Atlantic, but relative bias is larger due to different cloud properties indicating that this issue persists globally.</p>

Faculty of Engineering School of Civil and Enviromental Engineering 9506023j PMISTRY@WEBMAIL.co.za / This report investigates the viability of satellite remote sensing in monitoring the rehabilitation of coal discard dumps. Four levels of thermal monitoring data were assessed in this project. These were: ground and below surface temperature probes; aerial thermal and atmospheric monitoring surveys; high altitude aircraft; and satellites. Remote sensing methods measure only variation of temperatures on the surface of the dump. Fires on discard dumps are sub-surface fires, and the depth and extent of the fire below the surface cannot be easily inferred. The resolution of satellite sensors is a limiting factor for detecting individual hotspots on dumps. Small mine dumps occupy just a few pixels and the position of fires cannot be accurately assessed. Although the larger dumps are discernable, the variation of temperatures across the dump cannot be easily determined. For the present, aircraft monitoring may be the most viable means of monitoring spontaneous combustion in coal discard dumps, until satellite resolutions improve further.

Orientador: Roberto Wagner Lourenço / Resumo: O estudo dos fenômenos atmosféricos requer a compreensão de complexas relações e interações dos sistemas naturais e/ou antrópicos. As alterações da superfície terrestre alteram os processos de troca de energia entre a superfície e atmosfera em diferentes escalas, atuando na variação de temperatura da superfície e do ar, na intensidade dos fluxos de energia disponível na superfície e nas variações da energia armazenada na vegetação. A utilização de técnicas de sensoriamento remoto na compreensão dessas relações, a partir de uma abordagem geossistêmica, auxilia otimizando a obtenção de dados, no refinamento e acurácia destes e na análise sistêmica, tornando-se uma ferramenta importante para o entendimento dos processos ecológicos e antrópicos que agem nos sistemas terrestres. Neste contexto, este trabalho teve como objetivo a análise do comportamento espacial da Temperatura de Superfície (Ts) e albedo na Bacia Hidrográfica do Rio Una, Ibiúna - SP, a partir de imagens do sensor MODIS dos satélites TERRA e Aqua para os meses de Janeiro e Agostos dos anos de 2004, 2008, 2012 e 2015, considerando as modificações no uso do solo e ocupação da terra e as sazonalidades climáticas. A região de estudo vem sofrendo grandes mudanças no uso e cobertura da terra em função do crescimento urbano e das áreas de cultivo temporário e reflorestamento. Por fim, gerou-se um mapa da cobertura da terra para o ano de 2013, e a partir deste, realizou-se a análise do comportamento da Temp... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Atmospheric phenomena studies requires understanding about the complex relationships and interactions of natural and anthropic systems. Earth surface's changes alter the energy exchange processes between surface and atmosphere, at different scales, acting in : temperature variation of surface and air, the intensity of the energy streams available on the surface and the variations on energy stored in the vegetation. Remote sensing techniques utilization for the understanding of these relationships, in a geosystems approach, helps to optimize data acquisition, refinement and accuracy of these and systemic analysis, making it an important tool for the ecological and anthropic processes understanding, that act in terrestrial systems. In this context, the research's objective was the spatial behavior analysis of surface temperature (Ts) and albedo over the watershed area of the river Una (Ibiúna-SP), utilizing MODIS sensor images, from TERRA and Aqua satellites, captured in the months of January and August of 2004, 2008, 2012 and 2015, considering the changes in land use, land occupation and climatic seasonality. The study region has suffered major changes in land use and coverage on the basis of urban growth, cultivation areas and reforestation. So, a 2013 coverage map was generated, and from this, the behavior analysis of surface temperature and albedo was made. The results obtained were compared with the data of air temperature and rainfall data. / Mestre