Showing papers in "Advances in Space Research in 1993"

TL;DR: In this paper, a new technique to directly detect low energy neutral helium has been developed and successfully used in space for the first time, which makes possible the in-situ measurement of the local angular distribution of the flow of interstellar neutral helium in the inner heliosphere.

TL;DR: In this paper, a fast Fourier transform algorithm was used to analyze time series of images of Normalized Difference Vegetation Index values, and the results obtained for a case study on Zambia indicated that differences in vegetation development among map units of an existing agroclimatic map were not significant and reliable differences were observed among the map units obtained using the Fourier analysis.

TL;DR: Temporal correlations between NDVI, temperature and precipitation were computed to examine the spatial variability of the relationships between those parameters as well as to investigate the potential for the combined use of NDVI and temperature for global bioclimate monitoring as mentioned in this paper.

TL;DR: The International Reference Ionosphere 1990 (IRI-90) handbook as discussed by the authors summarizes the work and studies that led to IRI-90 and provides an overview over this latest version of the model.

TL;DR: In this paper, the slope of the soil line corresponded to the ratio of the single scattering albedos corresponding to the two wavebands where the soil lines were defined, and the intercept originated from the difference in multiple scattering observed in each of the two wavelength bands used.

TL;DR: The most important investigations leading to the International Reference Ionosphere 1990 (IRI-90) are overviewed, and the latest version of the model is described in this paper, where shortcomings and limitations of the IRI-90 are pointed out, together with the ways of overcoming them.

TL;DR: In this paper, the authors provide a background of VCI development, data processing and outlines a PC-based system designed for early-warning drought diagnostics, which has proved to be a good indicator of drought.

TL;DR: In this paper, the dynamics of radially expanding magnetic clouds is rigorously analyzed within the framework of ideal MHD, where the cloud is modelled as a cylindrically symmetric magnetic flux rope.

TL;DR: The problems facing forecasters of solar-terrestrial activity were discussed at the Solar-Terrestrial Predictions Workshop held in Ottawa, Canada in May 1992 as mentioned in this paper, and the results and recommendations of the scientists participating in this Workshop are presented.

TL;DR: In this article, the properties of solar flare accelerated particles using gamma ray observations were studied and the effects of the abundance variations implied by the gamma ray data on these parameters were investigated.

TL;DR: In this article, the ERS-1 scatterometer measurements in relation to wind speed and direction have been carried out at ECMWF, complementary to the Haltenbanken field campaign, and it is shown that measurement noise is low and a solution surface is generally well-defined in 3D measurement space except at low wind speed at the inner edge of the swath.

TL;DR: In this article, the authors found that the MeV ion populations from a variety different of solar and interplanetary sources have quite distinct abundances and spectra, relative to coronal abundances, and that the enhancements are probably produced by selective absorption of plasma waves in these events.

TL;DR: In this article, the summer-to-spring ratio of atomic hydrogen exceeds a factor of 4 at 10 μbar (80 km) at 40°N, where the Meinel band emission of ozone is proportional to the product of ozone and hydrogen and very large annual and semiannual changes are found in this region.

TL;DR: The International Reference Ionosphere 1990 (IRI-90) handbook as mentioned in this paper summarizes the work and studies that led to IRI-90 and provides an overview over this latest version of the model.

TL;DR: In this paper, the authors discuss the X-ray properties of known cataclysmic variables (CVs) as observed in the ROSAT All-Sky Survey and present a status report on programs to identify CVs among the newly discovered ROSAT Xray sources.

TL;DR: Oscillatory thermocapillary flows are experimentally investigated for half-zone, floating zone, rectangular, and cylindrical configurations for a variety of operating conditions as mentioned in this paper, and the onset conditions for oscillations, free-surface temperature distributions and flow structures are determined and compared to indicate the differences among them.

TL;DR: Singly ionized suprathermal lunar pick-up ions were observed upstream of the earth's bow shock between August and December 1985 using the time-of-flight spectrometer SULEICA on the AMPTE/IRM satellite as mentioned in this paper.

TL;DR: In this article, the authors used GIS approach to select suitable sites for checkdams for harvesting rain water in Alur taluk of Hassan district, Karnataka, India covering 400 sq km. area was chosen.

TL;DR: A pool boiling experiment on a sounding rocket (TR-IA 1st Flight) was conducted with a transparent glass heater and an interferometer under a relatively low heat flux.

TL;DR: The combination of gradient, curvature and heliospheric neutral sheet (HNS) drifts with interaction regions (IRs) occurring in the inner heliosphere and merged interaction regions in the outer Heliosphere would enable one to successfully simulate complete 11 and 22-yr cycles with comprehensive, global modulation models as discussed by the authors.

TL;DR: In this article, preliminary results from the ROSAT ALL-SKY X-ray and X-UV survey with imaging telescopes are presented, showing that about 60,000 new X-rays and 400 new XUV /1/ sources were detected.

TL;DR: In this paper, the dynamics of the equatorial thermosphere and the F-region plasma are reviewed, highlighting some features observed with the San Marco satellite, the AE-E, and the DE-2, as well as with ground-based facilities at Arecibo and Jicamarca.

TL;DR: Geosat altimeter derived sea surface height (SSH) anomaly fields have been optimally interpolated onto a regular space time grid using both crossover data from the non-repeating Geodetic Mission (GeOSat-GM) and collinear data from Geosat-ERM, during which six major and at least two minor Loop Current eddies were directly observed.

TL;DR: In this paper, a distributed hydrological model and two microwave remote sensors (Push Broom Microwave Radiometer and Synthetic Aperture Radar) were compared with ground measurements collected during the MAC-HYDRO'90 experiment over a 7.4km2 watershed in central Pennsylvania.

TL;DR: In this article, the tensile strength of loosely bound Al 2 O 3 particles of 1 to 10 μm size charged by ions was derived and the dependence of the strength on the particle size can be well fitted by an inverse square power law.

TL;DR: In this paper, the authors report on the preliminary analysis of fast temporal fluctuations observed in hard X-ray bursts, as recorded by the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory.

TL;DR: In this article, the use of ENAs to study the outer heliosphere is discussed, and the detection of ENA under stringent observational conditions is addressed, where the ENA detectors are examined.

TL;DR: In this paper, the spatial densities and fluxes of 6,620 objects tracked by the USSpaceCom surveillance groundstation network are analyzed in a 2D (altitude/latitude) distribution model.

TL;DR: In this article, the results for the tidally coherent part of the subdaily Earth rotation variations determined from the analysis of very long baseline interferometry (VLBI) data are discussed.