Future exploration of Venus (post-Pioneer Venus 1978)

A comprehensive study was performed to determine the major scientific unknowns about the planet Venus to be expected in the post-Pioneer Venus 1978 time frame. Based on those results the desirability of future orbiters, atmospheric entry probes, balloons, and landers as vehicles to address the remaining scientific questions were studied. The recommended mission scenario includes a high resolution surface mapping radar orbiter mission for the 1981 launch opportunity, a multiple-lander mission for 1985 and either an atmospheric entry probe or balloon mission in 1988. All the proposed missions can be performed using proposed space shuttle upper stage boosters. Significant amounts of long-lead time supporting research and technology developments are required to be initiated in the near future to permit the recommended launch dates

Estimating Carbon Pool and Carbon Release due to Tropical Deforestation Using High-resolution Satellite Data: Carbon Release due to Tropical Deforestation

Forest-cover in the tropics is changing rapidly due to indiscriminate removal of timber from many localities. The main focus of the study is to develop an operational tool for monitoring biomass and carbon pool of tropical forest ecosystems. The method was applied to a test site of Bangladesh. The research used Landsat ETM+, Landsat TM and IRS pan images of 2001, 1992 and 1999 respectively. Geometrically corrected Landsat ETM+ imagery was obtained from USGS and adjusted to the field using GPS. Historical images were corrected using image-to-image registration. Atmospheric correction was done by modified dark object subtraction method. Stratified sampling design based on the remote sensing image was applied for assessing the above-ground biomass and carbon content of the study area. Field sampling was done during 2002-2003. Dbh and height of all the trees inside the sample plots were measured. Field measurement was finally converted to carbon content using allometric relations. Three different methods: stratification, regression and k-nearest neighbors were tested for combining remote sensing image information and field-based terrestrial carbon pool. Additional field sampling was conducted during 2003-2004 for testing the accuracy. Finally regression method was selected. The amount of carbon released and sequestrated from the ecosystem was estimated. The application of the developed method would be quite useful for understating the terrestrial carbon dynamics and global climate change

Design, implementation, and characterisation of a novel lidar ceilometer

A novel lidar ceilometer prototype based on divided lens optics has been designed, built, characterised, and tested. The primary applications for this manufacturable ground-based sensor are the determination of cloud base height and the measurement of vertical visibility. First, the design, which was developed in order to achieve superior performance at a low cost, is described in detail, along with the process used to develop it. The primary design considerations of optical signal to noise ratio, range-dependent overlap of the transmitter and receiver channels, and manufacturability, were balanced to develop an instrument with good signal to noise ratio, fast turn-on of overlap for detection of close range returns, and a minimised number of optical components and simplicity of assembly for cost control purposes. Second, a novel imaging method for characterisation of transmitter-receiver overlap as a function of range is described and applied to the instrument. The method is validated by an alternative experimental method and a geometric calculation that is specific to the unique geometry of the instrument. These techniques allow the calibration of close range detection sensitivity in order to acquire information prior to full overlap. Finally, signal processing methods used to automate the detection process are described. A novel two-part cloud base detection algorithm has been developed which combines extinction-derived visibility thresholds in the inverted cloud return signal with feature detection on the raw signal. In addition, standard approaches for determination of visibility based on an iterative far boundary inversion method, and calibration of attenuated backscatter profile using returns from a fully-attenuating water cloud, have been applied to the prototype. The prototype design, characterisation, and signal processing have been shown to be appropriate for implementation into a commercial instrument. The work that has been carried out provides a platform upon which a wide range of further work can be built

THE APPLICATION OF REMOTE SENSING TECHNIQUES IN HYDROLOGY

REMOTE SENSING, which may be simplistically defined as ’the collection and interpretation of emitted or reflected radiation from a body’, offers the potential for accurate interpolation of surface data and even for its direct measurement on scales ranging from local to world wide. This dissertation has been written primarily for the hydrologist, engineer, environmentalist or student who needs to measure changes either in space or time of hydrological variables such as water quality, but who has little practical knowledge of remote sensing or how it may be of assistance to him. It may be regarded as a reference document which, as a result of internal cross referencing and comprehensive external subject referencing, should enable the reader to acquire a background knowledge of remote sensing theory which is relevant to his interests, to understand the advantages and difficulties of applying remote sensing techniques to his measurement problem and to obtain further information about remote sensing applications which have already been undertaken within his field of interest. The dissertation centres on the hydrological situation in England and Wales by initially outlining the structure of their water industries. The main hydrological measurement objectives in terms of water resources, water supply, effluent disposal and flood prediction and warning are identified and some advantages of incorporating remote sensing into hydrological measurement programmes are suggested. The physical theory of remote sensing is described and the main methods of collecting and analysing remotely sensed data are given. A topic by topic analysis of the most suitable ways of tackling specific hydrological measurement problems through the use of remote sensing is made and the dissertation concludes with an assessment of the likely future use of remote sensing in hydrological measurement programmes in genera

Digital processing of satellite images for lithological discrimination and classification in arid regions

Satellite images have been used as a complementary information for geological studies. In order to realise the maximum potential of satillite imagery, then improvements are needed, both in the visual presentation of such images, and in their automatic classification , in order to reveal the rock differences. Methods of processing imagery, were evaluated (band ratio, principal components, decorrelated stretch and maximum likelihood) and new (canonical regression, hue-saturation-intensity HSI transform, with modified manipulation, and watershed) were evaluated with respect to their ability to reveal rock differences. It was found that the HSI method gave the best results, both for visual presentation and automatic classifcation. This method has the ability to enhance both spectral and spatial information simultaneously without any data loss which is not the case in the other image enhancement methods (band ratio, principal components or decorrelation stretch). For automatic classification, the 'hue' images produced by the HSI transformation typically gave accurate (91%) classification of all the major rock types. Further, it was shown that the watershed method of classification was superior error rate = 9% to the maximum likelihood method (error rate 14%) for the same inputs. The new method of canonical regression was evaluated and although it was not very successful, the results were encouraging and it was concluded that this method may enable the estimation of the chemical composition of exposed rocks directly from satellite imagery

LASA (Lidar Atmospheric Sounder and Altimeter) Earth Observing System. Volume 2D: Instrument Panel Report

The Earth Observing System (Eos) will provide an ideal forum in which the stronly synergistic characteristics of the lidar systems can be used in concert with the characteristics of a number of other sensors to better understand the Earth as a system. Progress in the development of more efficient and long-lasting laser systems will insure their availability in the Eos time frame. The necessary remote-sensing techniques are being developed to convert the Lidar Atmospheric Sounder and Altimeter (LASA) observations into the proper scientific parameters. Each of these activities reinforces the promise that LASA and GLRS will be a reality in the Eos era

Mapping methods and observations of surficial snow/ice cover at Redoubt and Pavlof volcanoes, Alaska using optical satellite imagery

Thesis (M.S.) University of Alaska Fairbanks, 2014Alaska is a natural laboratory for the study of how active volcanism interacts with underlying seasonal snow, perennial snow, and glacial ice cover. While over half of the historically active volcanoes in Alaska have some degree of perennial snow or glacial ice, all Alaskan volcanoes have a covering of seasonal snow for a period of time throughout the year. Previous research has centered on how volcanic deposits erode away the underlying snow/ice cover during an eruption, producing volcanic mudflows called lahars. Less emphasis has been placed on how variations in the snow/ice cover substrate effect the efficiency of meltwater generation during a volcanic eruption. Glacial ice, perennial snow, and seasonal snow can all contribute significantly to meltwater, and therefore the variations in the types of snow/ice cover present at Alaskan volcanoes must be analyzed. By examining the changing spatial extent of seasonal snow present at a volcano during multiple Alaskan summers, the approximate boundaries of perennial snow and ice can be mapped as the snow/ice cover consistently present at the end of each ablation season. In this study, two methods of snow/ice cover mapping for Redoubt and Pavlof volcanoes are analyzed for efficiency and accuracy. Identification of the best method allows for mapping of the snow/ice cover consistently present during each Alaskan summer month over at least two different years. These maps can serve as approximations for the snow/ice cover likely to be present at both volcanoes during each summer month. Volcanic deposits produced during the 2009 Redoubt and 2013 Pavlof eruptions are spatially linked to these snow/ice cover maps so that future research can focus on the interaction between deposits and type of snow/ice substrate. Additional observations and conclusions are made regarding how the visible snow/ice cover varies during and after each eruption.Chapter 1. Introduction -- 1.1. Background -- 1.2. Comparison of snow/ice cover mapping methods for Alaskan volcanoes -- 1.3. Mapping snow/ice on Redoubt and Pavlof during quiescence and eruption -- 1.4. Summary of final outcomes -- 1.5. References -- Chapter 2. Methods for snow/ice cover mapping of Redoubt and Pavlof volcanoes using optical satellite imagery -- 2.1. Introduction -- 2.1.1. Satellite remote sensing of glaciers and snow cover in Alaska -- 2.1.2. Previous work and methods for studying snow/ice on volcanoes -- 2.1.3. Challenges of mapping snow/ice cover at Alaskan volcanoes -- 2.2. Setting of Redoubt volcano -- 2.2.1. Basic setting of Redoubt volcano -- 2.3. Setting of Pavlof volcano -- 2.3.1. Basic setting of Pavlof volcano -- 2.4. Methods -- 2.4.1. Previous work in snow/ice cover mapping using satellite imagery -- 2.4.2. Sensors used for snow/ice cover mapping -- 2.4.3. Pre-processing of satellite imagery -- 2.4.4. Methods used to map snow/ice cover at Redoubt and Pavlof -- 2.4.5. Technique 1: band ratios -- 2.4.6. Technique 2: principal component analysis -- 2.4.7. Technique 3: linear spectral unmixing -- 2.5. Results and discussion -- 2.5.1. Snow/ice cover mapping using threshold method -- 2.5.2. Snow/ice cover mapping using linear spectral unmixing method -- 2.5.3. Improvements to linear spectral unmixing method for snow/ice cover mapping -- 2.5.4. Validation of results -- 2.6. Conclusion -- 2.7. Figures -- 2.8. Tables -- 2.9. References -- Chapter 3. Observations of surficial snow/ice cover changes due to seasonal and eruptive influences on Redoubt and Pavlof volcanoes, Alaska using optical remote sensing -- 3.1. Introduction -- 3.1.1. Alaskan volcanoes -- 3.2. Volcano-snow/ice interactions -- 3.2.1. Short term interactions -- 3.2.2. Long term interactions -- 3.2.3. Lahar formation and hazards -- 3.2.4. Influence of snow/ice substrate type on lahar generation -- 3.3. Background on Redoubt volcano -- 3.3.1. Setting of Redoubt volcano -- 3.3.2. Recent eruptions at Redoubt volcano -- 3.3.3. Eruption effects on Drift Glacier -- 3.3.4. Lahar hazards at Redoubt volcano -- 3.4. Background on Pavlof volcano -- 3.4.1. Setting of Pavlof volcano -- 3.4.2. Recent eruptions at Pavlof volcano -- 3.4.3. Lahar hazards at Pavlof volcano -- 3.5. Methods -- 3.5.1. Sensors used to create Products 1, 2, and 3 -- 3.5.2. Methods used to produce Product 1: individual snow/ice cover maps -- 3.5.3. Methods used to produce Product 2: snow/ice cover summary maps -- 3.5.4. Methods used to produce Product 3: composite maps of eruptive deposits and snow/ice cover -- 3.6. Results and discussion -- 3.6.1. Product 1: individual snow/ice cover maps of Redoubt subset -- 3.6.2. Product 2: snow/ice cover summary maps of Redoubt subset -- 3.6.3. Product 3: composite maps of eruptive deposits and snow/ice cover of Redoubt subset -- 3.6.4. Product 1: individual snow/ice cover maps of Pavlof subset -- 3.6.5. Product 2: snow/ice cover maps of Pavlof subset -- 3.6.6. Product 3: composite maps of eruptive deposits and snow/ice cover of Pavlof subset -- 3.7. Conclusion -- 3.8. Figures -- 3.9. Tables -- 3.10. References -- Chapter 4. Conclusion -- 4.1. Comparison of snow/ice cover mapping methods for Alaskan volcanoes -- 4.2. Mapping snow/ice on Redoubt and Pavlof during quiescence and eruption -- 4.3. Limitations and future work -- 4.4. References

Fourth Annual Earth Resources Program Review. Volume 4: National Oceanic and Atmospheric Administration programs and US Naval Research Laboratory programs

Conference of Earth Resources Program with emphasis on analysis of data obtained by aircraf

Earth resources: A continuing bibliography with indexes (issue 58)

This bibliography lists 500 reports, articles, and other documents introduced into the NASA scientific and technical information system between April 1 and June 30, 1988. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis