Showing papers in "Advances in Space Research in 1998"

TL;DR: In this article, the reflectance spectra of higher plant leaves were considered with special reference to remote sensing of chlorophyll concentration, and the wavelength of the red edge position of reflectance spectrum correlated very closely with the reflectances at 550 and 700 nm.

TL;DR: In this article, the authors attempted to catalogue all the published reports of geomagnetic effects on electrical systems and show their occurrence in the context of the solar cycle and geOMagnetic activity variations for the years 1844 to 1996.

TL;DR: In this paper, the authors proposed a method of identification of variations induced by seismic activity within the ionosphere and found that seismic activity is an important source of ionospheric variability.

TL;DR: In this paper, the use of interferometric SAR, RADARSAT, and airborne SAR combined with Landsat, TM images to identify diagnostic features of landslides and their slope characteristics.

TL;DR: In this paper, the authors discuss some of the principal adverse space environmental effects presently known including trapped magnetospheric radiation, solar energetic particles, geomagnetic storms, and magnetosphere substorms, and conclude that practical and effective methods of predicting and mitigating space weather effects are close at hand.

TL;DR: In this article, the authors determined the survivability of osmophilic microorganisms in space, as well as examined the DNA breakage in osmphilic cells exposed to solar UV-radiation plus vacuum and to vacuum only.

TL;DR: In this paper, the radio science experiment proposed for the Rosetta cometary mission consists in the transmission of electromagnetic waves between the landers and the orbiter through the comet to study its internal structure.

TL;DR: In this article, a strong correlation between high-speed solar wind speeds and the occurrence of high energy electrons in the Earth's outer radiation belts has been found, and the processes by which electrons are accelerated to high energies (E>1 MeV) are found to consist of two temporally distinct steps.

TL;DR: In this article, the information content and degrees of freedom for signal (DFOF) are used to quantify the information contained in the spectrum of the air and how to use it efficiently or effectively.

TL;DR: In this paper, a new model NPEX (Negative and positive power-laws EXponential) was introduced to represent the pulsar continuum, combining the NPEX continuum with the CYAB factor (cyclotron resonance scattering model) successfully fit the whole-band spectra of all the pulsars.

TL;DR: The primary forces governing particle behavior during clinorotation--gravity, diffusion and centrifugation--were mathematically assessed and indicated that results obtained using a clinostat followed trends resembling previous space flight results.

TL;DR: The AVHRR-based Vegetation Condition Index (VCI) and temperature condition index (TCI) have been developed and successfully used for monitoring drought in the USA., the Former Soviet Union, Zimbabwe, and China as mentioned in this paper.

TL;DR: In this paper, the authors used a modified version of the International Reference Ionosphere 1995 (IRI-95) model and augmented with a plasmaspheric electron content model to produce hourly global total electron content (TEC) maps from Global Positioning System (GPS) data.

TL;DR: In this paper, the distribution statistics of ESF events, mainly from ionograms, using the long term data sets available from equatorial and low latitude stations in Brazil and Argentina, are discussed on the basis of the longitude dependent magnetic declination angle that characterizes this region and on relevant thermospheric parameters.

TL;DR: In this paper, a satellite-based sounding system for detecting and mapping of the epicenter position of an earthquake was proposed, where the top-side sounder installed onboard the orbiting satellite was used to detect and map the ring structure forming within the ionosphere over the future epicenter.

TL;DR: In this paper, the authors present a reference NO model which is based upon the two satellite data sets and which covers a wide range of solar, geomagnetic and seasonal conditions, and show that a well defined decrease in NO during the decline of solar activity is observed at middle and high latitudes.

TL;DR: Critical sites in the CNS: the macula, and an interior brain point were chosen for the calculation of hit frequencies from galactic cosmic rays for a mission to Mars during solar minimum (i.e., at maximum cosmic-ray intensity), and variation of the position of the "target site" within the head plays only a small role in varying hit frequencies.

TL;DR: The findings suggest that the neuronal effects of heavy particle irradiation on long-term space flights may be significant, and may even supercede subsequent mutagenic effects in their mission capabilities.

TL;DR: The results indicate that the effects of exposure to heavy particles on behavioral endpoints cannot necessarily be extrapolated from studies using gamma rays, but require the use of heavy particles.

TL;DR: The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) as mentioned in this paper was designed to answer outstanding questions concerning the main objectives of the mission, including: very wide mass range from 1 amu to >300 amu; very high mass resolution (ability to resolve CO from N2 and 13C from 12CH); very wide dynamic range and high sensitivity; the ability to determine cometary gas and ion flow velocities and temperatures.

TL;DR: In this article, the NDVI-derived Vegetation Condition Index (VCI) was compared with vegetation density, biomass and reflectance measured in the fields, and the determination coefficient between AVHRR-derived vegetation state and actually measured vegetation density of more than 0.76 was achieved.

TL;DR: In this paper, the theory of ion injection at shocks developed earlier by the authors is complemented by the consideration of particle trapping in the downstream region, based on the interaction of particles with the large amplitude MHD-wave excited by the leaking ions.

TL;DR: In this paper, the authors evaluate theoretically the expected uncertainty, δα, resulting from atmospheric, oceanic, and radiometric errors, and show that δ α is inversely proportional to τ Λ, with the proportionality coefficient depending upon spectral channels used, sun-view geometry, and uncertainties in the model retrieval parameters.

TL;DR: The results demonstrated that space radiation environment could induce inheritable mutagenic effects on plant seeds, and verified the change in genetic material in the mutants.

TL;DR: Sensor output is described as a function of target and sensor body temperatures, and a generic (sensor independent) equation is provided that can be used to achieve +/- 0.2 C accuracy with Exergen sensors.

TL;DR: GPS-derived TEC data are compared with IRI95 and the European TEC model NTCM2 as discussed by the authors, and the results show that the latter does not include the plasmaspheric content.

TL;DR: In this article, the specific mechanism causing local time variations in the atomic oxygen recombination airglow emissions is investigated by examining the Lagrangian histories of air parcels in the wind fields of the diurnal tide generated by the Global Scale Wind Model of Hagan et al.

TL;DR: The Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) for the International Rosetta Mission is described in this article, which consists of two camera systems with a common electronics box.

TL;DR: In this article, the potential application of AVHRR data in regional scale drought monitoring in southern Africa is investigated using the NOAA-9 and 11 weekly Global Vegetation Index (GVI) data set for the period 1985 to 1994.

TL;DR: The primary goal of exobiological research is to reach a better understanding of the processes leading to the origin, evolution and distribution of life on Earth or elsewhere in the universe as discussed by the authors.