scholarly journals III. — Australie

1963 ◽  
Vol 19 ◽  
pp. 253-256 ◽  
Author(s):  
A. R. Hogg

In 1957 the Joint Observatory of Yale and Columbia Universities commenced a series of site surveys in Australia under the direction of Dr. I. Epstein. While astronomers at Mount Stromlo Observatory were greatly interested in this activity, it was not until 1958 that Mount Stromlo actively commenced site testing. Tests were initiated in the first instance with a desire to find a not-too-distant location suitable for a field station where observing conditions would be better than those at Mount Stromlo, and later with the idea of finding a site anywhere in Australia which would satisfy the needs of a large telescope.

1984 ◽  
Vol 79 ◽  
pp. 417-428
Author(s):  
A. Ardeberg ◽  
H. Lindgren

AbstractA report is given on the site-testing programme for a Very Large Telescope in Chile. Data are now available from seven months of investigations. Comments are made on the places which have so far seemed most attractive. Meteorological data from constant monitoring of a coastal mountain, Paranal, are presented and discussed. These data indicate an average percentage of photometric nights of around 85. Atmospheric integrated water-vapour content seems very low in the winter but relatively high in the summer. Other meteorological parameters seem favourable for astronomical observations.


1963 ◽  
Vol 19 ◽  
pp. 126-131
Author(s):  
C. R. Lynds

The concern has been expressed many times by Dr. Bowen and others that a significant portion of the seeing deterioration may occur in levels of the atmosphere very near the ground, within a few tenths of meters of the ground. When I refer to the quality of seeing I am refering to the image size one observes in a telescope of very large aperture and I will assume that this is equivalent to image motion as observed in telescopes of very small aperture. I will not attempt a further justification for this concern; however this is the basis for the studies we are just beginning at Kitt Peak, where we will attempt to quantitatively show whether or not there is need for concern about the very low levels of the atmosphere. So we begin with the thesis that much of the poor seeing observed at a site, the enlargement of photographic or visual images as observed through a large telescope, is due to refractive inhomogeneities in the lower levels of the atmosphere, within less than 100 m above the telescope. We presume that these inhomogeneities are of local origin and that their distribution and motion is determined primarily by site topography, wind direction and velocity. The few experiments we have made thus far at Kitt Peak have been designed to ascertain quantitatively the importance of these factors. Our approach has been to make observations of the large-aperture seeing with simultaneous observations of the thermal structure of the air accessible to us immediately above the telescope.


1974 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
DJ Dunsmore

An unconfined, almost completely tagged rabbit population on a site of about 100 ha was studied by observation and trapping for 5 years. The commencement of the study coincided approximately with the incorporation of the area into the Kosciusko National Park, the elimination of grazing by domestic livestock, and the cessation of the previously almost annual burning of the area. During the 5-yr study the fecundity of the rabbits declined to little more than half the initial level. This was not a result of the concurrently increasing age of the population, which was shown to be quite unrelated. It was also shown that the 1yr old rabbits were less fecund than the older rabbits, whose fecundity remained constant. Although it appeared subjectively to be so, the area was not uniformly suitable for the survival of rabbits. In one of its four subdivisions adult survival was much better than in the others; and in one of the others it was much the worst. During the study there was considerable immigration to the area, presumably balanced by migration. Females tended to remain where they were born and in no case changed from one breeding group to another. Males were considerably less sedentary than the females.


2017 ◽  
Vol 44 (4) ◽  
pp. 291 ◽  
Author(s):  
Michael M. Driessen ◽  
Peter J. Jarman ◽  
Shannon Troy ◽  
Sophia Callander

Context Understanding how different camera trap models vary in their ability to detect animals is important to help identify which cameras to use to meet the objectives of a study. Aims To compare the efficacy of four camera trap models (representing two commonly used brands of camera, Reconyx and Scoutguard) to detect small- and medium-sized mammals and birds. Methods Four camera models were placed side by side, focused on a bait station, under field conditions, and the numbers of triggers and visits by mammals and birds were compared. Trigger=camera sensor is activated and records an image of an animal. Visit=one or a sequence of triggers containing one or more images of a species, with no interval between animal images greater than 5min. Key results The Scoutguard 530V camera recorded fewer than half of the triggers and visits by all animals that the Reconyx H600, Scoutguard 560K and Keepguard 680V cameras recorded. The latter three cameras recorded similar numbers of visits by mammals, but the Reconyx H600 recorded fewer triggers by medium-sized mammals than the Keepguard 680V. All camera models failed to detect a substantial proportion of the total known triggers and visits by animals, with a greater proportion of visits detected (14–88%) than triggers (5–83%). All camera models recorded images with no animals present (blanks), with Reconyx H600 recording the fewest blank images. Conclusions Camera trap models can vary in their ability to detect triggers and visits by small- and medium-sized mammals and birds. Some cheaper camera models can perform as well as or better than a more expensive model in detecting animals, but factors other than cost may need to be considered. Camera traps failed to detect a substantial proportion of known triggers and visits by animals. Number of visits is a more useful index of animal activity or abundance than number of triggers. Implications Variation in camera performance needs to be taken into consideration when designing or comparing camera surveys if multiple camera models are used, especially if the aim is to compare animal activity or abundance. If maximising the number of animal visits recorded at a site is important, then consideration should be given to using two or more cameras.


1966 ◽  
Vol 27 ◽  
pp. 193-200

I call then first for comments about site development for large telescopes. Byron Hill has been for a long time the superintendent of the Palomar Mountain Station of the Mt Wilson and Palomar Observatories, and I think he is peculiarly fitted to tell us about the construction of the initial mountain facilities, and transport, support shop, and so on.


2009 ◽  
Vol 40 ◽  
pp. 111-114
Author(s):  
A. Gardini ◽  
A. Damiani ◽  
M. Storini
Keyword(s):  
Dome A ◽  

2004 ◽  
Vol 21 (3) ◽  
pp. 256-263 ◽  
Author(s):  
Paolo G. Calisse ◽  
Michael C. B. Ashley ◽  
Michael G. Burton ◽  
Michael A. Phillips ◽  
John W. V. Storey ◽  
...  

AbstractWe have developed a 350 μm radiometer to perform automated site testing in remote regions of Antarctica. In summer 2000–2001 the instrument operated at Concordia, a new station under construction at Dome C on the Antarctic Plateau. We present the results, and compare them with the atmospheric opacity measured at the South Pole in the same five-week period. During these five weeks, observing conditions at Dome C were, on average, substantially better than those at the South Pole.


1967 ◽  
Vol 1 (2) ◽  
pp. 38-39 ◽  
Author(s):  
J.P. Wild

The radio installations at Culgoora Observatory evolved from the work carried out at Dapto field station between 1952 and 1965—which in turn was based on earlier observations. The basic instrument at Dapto was a radiospectrograph which produced two solar spectra per second over a frequency range originally of 40-210 MHz and finally of 5-2000 MHz. Until 1957 the Dapto radio spectrograph was the only one operating in the world and it fell upon this instrument to reveal many of the spectral phenomena which are now well known. The spectrograph observations referred to the total flux from the Sun observations with high directivity began at Dapto in 1958 with the introduction of a swept-frequency interferometer which measured the one-dimensional (east-west) positions of bursts and their approximate angular size over a continuous range of frequencies between 40 and 70 MHz. The results obtained from this combination of spectrograph and interferometer indicated that great advances would be made in our knowledge and understanding of the phenomena if two-dimensional metre-wavelength pictures of the Sun could somehow be recorded at short time intervals of about Is—again in combination with spectrographic observations. This requirement led to the start of the radioheliograph project. One requirement for this instrument was a site with linear dimensions of the order of 3x3 km. This was far too large for the Dapto site and a new site was selected at Culgoora in the north-west plains of New South Wales. The virtues of this site are its size, flatness, freedom from flooding, low radio noise level and accessibility from Sydney by air transport. Its sunshine and optical-seeing properties also made it a highly desirable site for optical observations, and developments assumed a new significance when Dr. Giovanelli and his optical colleagues decided to join us at the same observatory.


2012 ◽  
Vol 8 (S288) ◽  
pp. 296-297
Author(s):  
Chong Pei ◽  
Zhengyangg Li ◽  
Hualin Chen ◽  
Xiangyan Yuan

AbstractSites on Antarctic plateau have unique atmospheric properties that make them better than any mid-latitude sites as observatory locations. From site testing measurements over 4 years on Dome A carried out by the Chinese Center for Antarctic Astronomy, we can reasonably predict that Dome A is as good as or even better than Dome C, which has been proved to be the best astronomical site by now, and suitable for high angular resolution observations. Seeing monitoring is necessary for planning large scale ground-based optical astronomical telescopes. In 2012, the 28th Chinese Antarctic Scientific Expedition carried out preliminary daytime seeing monitoring using a Differential Image Motion Monitor (DIMM) placed at a height of 3.5m. The median seeing was found to be 0.8″. This will be the foundation of future research that obtains comprehensive and long-period monitoring of the site's optical parameters.


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