Rocket measurements of mesospheric ionization irregularities

The Langmuir-probe technique for measurement of electron concentration in the mesosphere is capable of excellent altitude resolution, of order 1 m. Measurements from nine rocket flights frequently show small-scale ionization structures in the altitude region 60–90 km. These are believed to be identical with regions of strong coherent backscatter seem by VHF radars at Jicamarca, Peru and Urbana, Illinois. They are believed to represent intermittent turbulence attributable to nonlinear interaction of waves in the mesosphere. Parameters of the turbulent regions are estimated.     

Siple VLF transmissions and their magnetospheric effects observed at Halley,Antarctica

Halley (75.5°S, 26.7°W, L = 4.3) is well placed for reception of subionospheric signals from the Siple transmitter. Occasionally a two-hop magnetospheric response to such signals can be observed. The data presented here are relevant to the problems of the radiation and propagation of VLF waves in the polar earth/ionosphere waveguide, duct stimulation and ducted wave amplification and the growth of triggered emissions. An upper sideband emission 20–40 Hz higher in frequency than the transmitted pulse was often received at a similar strength to, and simultaneously with the two-hop whistler mode echo.     

Responses of the upper middle atmosphere (60–110 km) to the stratwarms of the four pre-map winters (1978/9–1981/2)

The global developments of the four stratospheric events (～20–50 km) are described, using balloon, satellite and rocket data. Winds data for heights of 60–95 km, derived from L.F. drift (52°N, 15°E; Europe) and M.F. radar (52°N, 107°W; Canada), are then compared with the stratospheric data. There is clear evidence that the preliminary planetary waves often penetrate strongly to ～90 km, and that mean wind reversals also occur. However, there are dramatic differences between European and Canadian mesospheric responses.     

The giant planets and their satellites: Report on the Cospar Symposium,Ottawa, Canada,May 18–21, 1982

A $\text{Symposium on the Giant Planets and Their Satellites}$ was presented in conjunction with the Twenty-fourth Plenary Meeting of the Committee on Space Research. This paper summarizes the talks presented and places the remaining papers of this volume in context.     

Heavy ion action on yeast cells: inhibition of ribosomal-RNA synthesis, loss of colony forming ability and induction of mutants.

The action of heavy ions (Ar to U) accelerated to specific energies up to about 10 MeV/u (u=atomic mass unit) on different functions of yeast cells was studied. Ribosomal-RNA synthesis is inhibited according to a single-hit mechanism. Inactivation cross-sections were linearly related to the ratio of the squares of the effective charge Z* and the velocity of the ions. It is concluded from the analysis that the range of the most energetic delta-electrons is larger than previously assumed. There is no such dependence for survival and induction of mutants. In both cases cross-sections increase with the ion's specific-energy indicating an important contribution of long-range delta-electrons. The analysis shows that diploid yeast is not killed by a single-hit mechanism even by very heavy ions if the track width is too small. The relative importance of the penumbral region is even more pronounced with the more sensitive strains.     

Utility of landsat data in mineral exploration — a case study from Orissa,India

The utility of Landsat data in geosciences has been established beyond doubt. In this paper utility of Landsat data in mineral exploration has been highlighted.The geologic and geomorphic interpretation of Landsat data brought out two very significant and characteristic features in scene 152-046 in the southern part of Orissa. One was distinct tonal anomaly and other was occurance of flat planated surface devoid of vegetation and drainage on top of hills. This when checked on ground at Gandhmardan was found to be bauxite bearing lateritic plateau. When this known information was extrapolated over other regions in scenes 151-046 and 152-046, all other bauxitic — lateritic plateaus were picked up very easily on Landsat imagery.The information was further extrapolated in the southern scene No.152-047 where without doing much detailed geologic and geomorphic interpretation almost all other bauxitic — lateritic bodies occuring in the region were picked up. This proves the utility of Landsat data in mineral exploration.Moreover delineation of extent of such bodies could be done very accurately on Landsat imagery thus saving considerable time in the exploration programme.     

The Magellan project

Magellan is one of the future space projects being studied by the European Space Agency. The aim is to provide high resolution (λ/Δλ ≥ 2.5 × 10⁴) spectra in the far and extreme UV (between 500 and 1550 Å) of faint galactic and extragalactic objects (V ≤ 16^m). The instrument consists of a mechanical collimator, a concave holographic grating and a bidimensional photon-counting detector. A low resolution mode (λ/Δλ ≥ 10³) will provide spectra of objects as faint as 18^m.5. Magellan is planned as an observatory, operated in real time, and allowing interaction with the observer.     

Radiation transmission in adverse weather

A simplified practical approach to determining the effects of weather on the transmission of radiation at visible, infrared (IR), and millimetre (mm) wavelengths, with particular reference to the aircraft landing problem, is outlined. Passive landing systems are studied. Landing categories related to visibility are defined. An extinction coefficient used to relate the effect of the atmosphere on the radiation detected by the human eye (or an imaging sensor onboard the aircraft) to the landing category and the calculation of this coefficient are discussed. The approach makes use of data from openly available literature. Results have been found useful in indicating the effects of adverse weather on imaging sensor performance for an enhanced vision aircraft-mounted landing system. As an example of the technique, the method of determining the extinction coefficients in fog for infrared radiation is outlined     

Development of B-1 antenna measurement test bed

The establishment of a B-1 test bed is chronicled from identification of the requirement to the initial measurements program. Disassembly, modification, and reassembly of the airframe are covered. Future modifications and measurements are previewed. The facilities at which the B-1 test bed is located are briefly discussed