3,062 research outputs found
Telepresence in the human exploration of Mars: Field studies in analog environments
This paper describes the role of telepresence in performing exploration of Mars. As part of an effort to develop telepresence to support Mars exploration, NASA is developing telepresence technology and using it to perform exploration in space analog environments. This paper describes experiments to demonstrate telepresence control of an underwater remotely operated vehicle (TROV) to perform scientific field work in isolated and hostile environments. Toward this end, we have developed a telepresence control system and interfaced it to an underwater remotely operated vehicle. This vehicle was used during 1992 to study aquatic ecosystems in Antarctica including a study of the physical and biological environment of permanently ice-covered lake. We also performed a preliminary analysis of the potential for using the TROV to study the benthic ecology under the sea ice in McMurdo sound. These expeditions are opening up new areas of research by using telepresence control of remote vehicles to explore isolated and extreme environments on Earth while also providing an impetus to develop technology which will play a major role in the human exploration of Mars. Antarctic field operations, in particular, provide an excellent analog experience for telepresence operation in space
Interannual surface evolution of an Antarctic blue-ice moraine using multi-temporal DEMs
Multi-temporal and fine resolution topographic data products are increasingly used to quantify surface elevation change in glacial environments. In this study, we employ 3D digital elevation model (DEM) differencing to quantify the topographic evolution of a blue-ice moraine complex in front of Patriot Hills, Heritage Range, Antarctica. Terrestrial laser scanning (TLS) was used to acquire multiple topographic datasets of the moraine surface at the beginning and end of the austral summer season in 2012/2013 and during a resurvey field campaign in 2014. A complementary topographic dataset was acquired at the end of season 1 through the application of Structure-from-Motion with multi-view stereo (SfM-MVS) photogrammetry to a set of aerial photographs acquired from an unmanned aerial vehicle (UAV).Three-dimensional cloud-to-cloud differencing was undertaken using the Multiscale Model to Model Cloud Comparison (M3C2) algorithm. DEM differencing revealed net uplift and lateral movement of the moraine crests within season 1 (mean uplift ~0.10 m), and surface lowering of a similar magnitude in some inter-moraine depressions and close to the current ice margin, although we are unable to validate the latter. Our results indicate net uplift across the site between seasons 1 and 2 (mean 0.07 m). This research demonstrates that it is possible to detect dynamic surface topographical change across glacial moraines over short (annual to intra-annual) timescales through the acquisition and differencing of fine-resolution topographic datasets. Such data offer new opportunities to understand the process linkages between surface ablation, ice flow, and debris supply within moraine ice
Automatic Features Extraction From Time Series Of Passive Microwave Images For Snowmelt Detection Using Deep-Learning – A Bidirectional Long-Short Term Memory Autoencoder (Bi-Lstm-Ae) Approach.
The Antarctic surface snowmelt is prone to the polar climate and is common in its coastal regions. With about 90 percent of the planet\u27s glaciers, if all of the Antarctica glaciers melted, sea levels will rise about 58 meters around the planet. The development of an effective automated ice-sheet snowmelt monitoring system is therefore crucial.
Microwave remote sensing instruments, on the one hand, are very sensitive to snowmelt and can see day and night through clouds, allowing us to distinguish melting from dry snow and to better understand when, where, and for how long melting has taken place. On the other hand, deep-learning (DL) algorithms, which can learn from linear and non-linear data in a hierarchical way robust representations and discriminative features, have recently become a hotspot in the field of machine learning and have been implemented with success in the geospatial and remote sensing field.
This study demonstrates that deep learning, particularly long-short memory autoencoder architecture (LSTM-AE) is capable of fully exploiting archives of passive microwave time series data. In this thesis, An LSTM-AE algorithm was used to reduce and capture essential relationships between attributes stored as brightness temperature within pixel time series and k-means clustering is applied to cluster the leaned representations. The final output map highlights the melt extent in Antarctica
COBE's search for structure in the Big Bang
The launch of Cosmic Background Explorer (COBE) and the definition of Earth Observing System (EOS) are two of the major events at NASA-Goddard. The three experiments contained in COBE (Differential Microwave Radiometer (DMR), Far Infrared Absolute Spectrophotometer (FIRAS), and Diffuse Infrared Background Experiment (DIRBE)) are very important in measuring the big bang. DMR measures the isotropy of the cosmic background (direction of the radiation). FIRAS looks at the spectrum over the whole sky, searching for deviations, and DIRBE operates in the infrared part of the spectrum gathering evidence of the earliest galaxy formation. By special techniques, the radiation coming from the solar system will be distinguished from that of extragalactic origin. Unique graphics will be used to represent the temperature of the emitting material. A cosmic event will be modeled of such importance that it will affect cosmological theory for generations to come. EOS will monitor changes in the Earth's geophysics during a whole solar color cycle
Aerospace medicine and biology: A continuing bibliography with indexes, supplement 204
This bibliography lists 140 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1980
Unmanned Aerial Vehicles (UAVs) in environmental biology: A Review
Acquiring information about the environment is a key step during each study in the field of environmental biology at different levels, from an individual species to community and biome. However, obtaining information about the environment is frequently difficult because of, for example, the phenological timing, spatial distribution of a species or limited accessibility of a particular area for the field survey. Moreover, remote sensing technology, which enables the observation of the Earth’s surface and is currently very common in environmental research, has many limitations such as insufficient spatial, spectral and temporal resolution and a high cost of data acquisition. Since the 1990s, researchers have been exploring the potential of different types of unmanned aerial vehicles (UAVs) for monitoring Earth’s surface. The present study reviews recent scientific literature dealing with the use of UAV in environmental biology. Amongst numerous papers, short communications and conference abstracts, we selected 110 original studies of how UAVs can be used in environmental biology and which organisms can be studied in this manner. Most of these studies concerned the use of UAV to measure the vegetation parameters such as crown height, volume, number of individuals (14 studies) and quantification of the spatio-temporal dynamics of vegetation changes (12 studies). UAVs were also frequently applied to count birds and mammals, especially those living in the water. Generally, the analytical part of the present study was divided into following sections: (1) detecting, assessing and predicting threats on vegetation, (2) measuring the biophysical parameters of vegetation, (3) quantifying the dynamics of changes in plants and habitats and (4) population and behaviour studies of animals. At the end, we also synthesised all the information showing, amongst others, the advances in environmental biology because of UAV application. Considering that 33% of studies found and included in this review were published in 2017 and 2018, it is expected that the number and variety of applications of UAVs in environmental biology will increase in the future
NASA Thesaurus supplement: A four part cumulative supplement to the 1988 edition of the NASA Thesaurus (supplement 3)
The four-part cumulative supplement to the 1988 edition of the NASA Thesaurus includes the Hierarchical Listing (Part 1), Access Vocabulary (Part 2), Definitions (Part 3), and Changes (Part 4). The semiannual supplement gives complete hierarchies and accepted upper/lowercase forms for new terms
Circulation, Winter 1996
Winter 1996 issue of CCPO Circulation featuring article The Ocean Mesoscalehttps://digitalcommons.odu.edu/ccpo_circulation/1038/thumbnail.jp
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The scope of science for the International Polar Year, 2007-2008
The International Polar Year 2007““2008 will be the largest internationally coordinated research programme in 50 years. It will be an intensive period of interdisciplinary science focused on the Arctic and the Antarctic. IPY 2007““2008 research activities were assembled from the ideas of researchers in more than 60 countries. A total of 228 projects have been endorsed by the ICSU/WMO Joint Committee for IPY 2007““2008. These projects have a strong interdisciplinary emphasis and address the six themes as well as education and outreach objectives. IPY projects will exploit new technological and logistical capabilities and strengthen international coordination of research. They aim to attract, engage and develop a new generation of researchers and raise the awareness, interest and understanding of polar residents, educators, students, the general public and decision makers worldwide. IPY projects will collect a broad-ranging set of samples, data and information which will be made available to an unprecedented degree. IPY 2007““2008 aims to leave a legacy of enhanced observational systems, facilities and infrastructure. The observational networks to be established during IPY include integrated ocean observing systems in both the Arctic and Southern Oceans, coordinated acquisition of satellite data products from multiple space agencies and observational systems for astronomy, sun““earth physics, atmospheric chemistry, meteorology, ecosystems, permafrost, glaciers and geophysics. Many observing systems within IPY will be developed within the framework of existing international global observing systems
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