Abstract: Although the existence of Oort's cometary cloud has been generally accepted, his hypothesis on its origin has been repeatedly called into question, in particular because of the large mass that Jupiter would also have simultaneously ejected out of the solar system. However, the extremely slow growth of particles in regions of small density seems to rule out that comets condensed "in situ" at their present large distances. Also, the accumulation of interstellar grains in satellite disks orbiting around the primitive solar nebula seems an "ad hoc" hypothesis that cannot be proved or disproved. Therefore, the most reasonable hypothesis is that comets were ejected from the region of the giant planets as a natural by-product of their accretion.

Abstract: The purpose of this work is to determine whether satellite derived cloud imagery can be effectively analyzed by optical means. Fourier transforms of a number of cloud images are obtained optically and digitized for analysis. Scenes are chosen from a 20 March 1975 frontal system across the Midwestern United States. Analysis is limited to three image categories: straight edges (jet stream), uniform cloud cover with globular texture (the frontal band), and broken cover or isolated globular texture (cumulonimbus activity). These are analyzed for time development of features as well as for type distinguishing features. The ROSA system at Engineering Topographic Laboratories is used in this analysis and the imagery is taken from the satellite ground station at the Atmospheric Sciences Laboratory. The results so far indicate that: (1) certain cloud features can be identified but that uniqueness of the identification must be established on a larger statistical sample, (2) the contrast level in "visual" imagery is not ideal and improvements in identification are expected to result from appropriate enhancements which can be applied "on line", (3) the scan line structure of the imagery can be more effectively exploited, and (4) this method of analysis merits a closer look.© (1977) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Abstract: From Sydney, Peter Pockley updates some recent developments in Australian science policy

Abstract: The experiment included surface level and airborne in situ cloud measurements of the exhaust effluents from the Titan IIIC solid rocket boosters Simultaneous visible spectrum photographic pictures of the ground cloud as well as infrared imaging of the cloud were obtained to study the cloud rise, growth, and direction of travel within the earth's surface mixing layer The NASA multilayer diffusion model predictions of cloud growth, direction of travel, and expected surface level effluent concentrations were made prior to launch and after launch using measured meteorological conditions Prelaunch predictions were used to position the effluent monitoring instruments, and the postlaunch predictions were compared with the measured data Measurement results showed that surface level effluent values were low, often below the detection limits of the instrumentation The maximum surface level hydrogen chloride concentration measured 50 parts per billion at about 8 km from the launch pad The maximum observed in-cloud (airborne measurement) hydrogen chloride concentration was 7 per million

Abstract: The paper shows how cloud elevations can be obtained from geosynchronous satellites within 15 min of an event and to an accuracy of less than 250 m. After careful consideration of pertinent factors, it is decided that a dual satellite system in parallel geosynchronous orbits would be the most feasible configuration for stereographic imaging of cloud systems. The discussion covers tracking accuracy, choice of imaging systems, data transmission and processing, image correlation, and proposed cloud heighting system. The described partially man-interactive system is substantially within the present state of the art and could be the basis for an interim system for cloud height determination.

Abstract: : In a previous report (AD-A033 037), a comparative study of statistical cloud classification techniques for discriminating scanning radiometer visible and infrared tropical cloud data was described. The present report explores the effects on classification performance of changes in the satellite, the location and time of observations, the sample window size, and the testing procedure (i.e., testing on a data set different from the design set). (Author)

Abstract: A technique is presented for determining cloud heights and amounts through the use of simultaneous. infrared and visible satellite radiance data. A set of simultaneous equations are developed which solve for cloud-top temperature (Tcld) and cloud amount (Acld) within the geometric field of view of the sensor. The cloud height is determined by comparing Tcld to upper air soundings, An error analysis is also presented showing the accuracy that can he obtained in Tcld and Acld when uncertainties exist in the measured visible and infrared radiances and in the assumptions required. Actual satellite measurements taken from the NOAA Scanning Radiometer (SR) are input into the technique and run for three specific geographical locations during several seasons where ground-based cloud observations are available. Results show an rms error in cloud amount of 0.2 and in cloud height of 0.5 km for a 75 km×75 km area for all cloud types except cirrus. For this case we have developed alternate solutions which ac...

Abstract: Abstract Mapping observations of the Perseus OB2 dark cloud and the supernova remnant W 44 region were made with the CO 115-GHz (J = 1–0) line. In the Perseus object, the CO antenna-temperature distribution was found to be similar to that of OH 1667-MHz emission, and the existence of a large CO-emitting region around the reflection nebula NGC 1333 was found. In the W 44 region, two molecular clouds of different radial velocities were seen; a 45-km s–1 cloud is distributed along the shell of W 44 and coincident in position with the one previously detected with H2CO and OH absorption lines, and a 35-km s–1 cloud was first observed but has no radio continuum counterpart. The present data are preliminary results of the galactic CO survey with the 1.5-m radio telescope at the Kisarazu Technical College.