The environmental vegetation index: A tool potentially useful for arid land management

The NOAA-6 AVHRR data sets acquired over South Texas and Mexico during the spring of 1980 and after Hurricane Allen passed inland are analyzed. These data were processed to produce the Gray-McCrary Index (GMI's) for each pixel location over the selected area, which area contained rangeland and cropland, both irrigated and nonirrigated. The variations in the GMI's appear to reflect well the availability of water for vegetation. The GMI area maps are shown to delineate and to aid in defining the duration of drought; suggesting the possibility that time changes over a selected area could be useful for irrigation management

Development and demonstration of a flutter-suppression system using active controls

The application of active control technology to suppress flutter was demonstrated successfully in the transonic dynamics tunnel with a delta-wing model. The model was a simplified version of a proposed supersonic transport wing design. An active flutter suppression method based on an aerodynamic energy criterion was verified by using three different control laws. The first two control laws utilized both leading-edge and trailing-edge active control surfaces, whereas the third control law required only a single trailing-edge active control surface. At a Mach number of 0.9 the experimental results demonstrated increases in the flutter dynamic pressure from 12.5 percent to 30 percent with active controls. Analytical methods were developed to predict both open-loop and closed-loop stability, and the results agreed reasonably well with the experimental results

Advanced Very High Resolution Radiometer (AVHRR) data evaluation for use in monitoring vegetation. Volume 1: Channels 1 and 2

Data from the National Oceanic and Atmospheric Administration satellite system (NOAA-6 satellite) were analyzed to study their nonmeteorological uses. A file of charts, graphs, and tables was created form the products generated. It was found that the most useful data lie between pixel numbers 400 and 2000 on a given scan line. The analysis of the generated products indicates that the Gray-McCrary Index can discern vegetation and associated daily and seasonal changes. The solar zenith-angle correction used in previous studies was found to be a useful adjustment to the index. The METSAT system seems best suited for providing large-area analyses of surface features on a daily basis

Meteorological satellite data: A tool to describe the health of the world's agriculture

Local area coverage data acquired aboard the TIROS-N satellite family by the advanced very high resolution radiometer systems was examined to determine the agricultural information current. Albedo differences between channel 2 and channel 1 of the advanced very high resolution radiometer LAC (called EVI) are shown to be closely correlated to the Ashburn vegetative index produced from LANDSAT multispectral scanner data which have been shown to vary in response to "greenness", soil moisture, and crop production. The statistical correlation between the EVI and the Ashburn Vegetative Index (+ or - 1 deg) is 0.86

Characteristics, of TIROS, GOES, DMSP and LANDSAT Systems

The characteristics of the TIROS, GOES, DMSP and LANDSAT systems of satellites are described. The data listed for each system are altitude of orbit, inclination/position, orbit type, orbits per day, expected operational lifetime and the sensor systems. The sensor systems are described as to wavelength of each channel, resolution, field of view and other pertinent information. Data information such as availability rate, collection method, primary use/application and how to obtain additional information is also given

A Farmer-Based Decision Support System for Managing Pasture Quality on Hill Country

Despite considerable effort to promote formal feed budgeting in New Zealand, survey data suggests it is only adopted by 20% of farmers (Nuthall & Bishop-Hurley, 1999). Recent work (Gray et al., 2003) has identified that farmers may use a different approach - micro-budgeting - to manage feed. Rather than operate at a whole farm level, micro-budgeting focuses at the paddock level. This paper describes micro-budgeting as used by a high performing hill country sheep and cattle farmer to manage pasture quality over spring and a decision support model developed to help other farmers undertake this proces

The Facilitation of Learning Groups: A Study of a Dairy Discussion Group Facilitator

Farm Management,

Granulation in K-type Dwarf Stars. II. Hydrodynamic simulations and 3D spectrum synthesis

We construct a 3D radiative-hydrodynamic model atmosphere of parameters Teff = 4820 K, log g = 4.5, and solar chemical composition. The theoretical line profiles computed with this model are asymmetric, with their bisectors having a characteristic C-shape and their core wavelengths shifted with respect to their laboratory values. The line bisectors span from about 10 to 250 m/s, depending on line strength, with the stronger features showing larger span. The corresponding core wavelength shifts range from about -200 m/s for the weak Fe I lines to almost +100 m/s in the strong Fe I features. Based on observational results for the Sun, we argue that there should be no core wavelength shift for Fe I lines of EW > 100 mA. The cores of the strongest lines show contributions from the uncertain top layers of the model, where non-LTE effects and the presence of the chromosphere, which are important in real stars, are not accounted for. The comparison of model predictions to observed Fe I line bisectors and core wavelength shifts for a reference star, HIP86400, shows excellent agreement, with the exception of the core wavelength shifts of the strongest features, for which we suspect inaccurate theoretical values. Since this limitation does not affect the predicted line equivalent widths significantly, we consider our 3D model validated for photospheric abundance work.Comment: A&A, in pres

High resolution spectroscopic study of red clump stars in the Galaxy: iron group elements

The main atmospheric parameters and abundances of the iron group elements (vanadium, chromium, iron, cobalt and nickel) are determined for 62 red giant "clump" stars revealed in the Galactic field by the Hipparcos orbiting observatory. The stars form a homogeneous sample with the mean value of temperature T=4750 +- 160K, of surface gravity log g = 2.41 +- 0.26 and the mean value of metallicity [Fe/H] = -0.04 +- 0.15 dex. A Gaussian fit to the [Fe/H] distribution produces the mean [Fe/H] = -0.01 dex and dispersion of [Fe/H] = 0.08 dex. The near-solar metallicity and small dispersion of [Fe/H] of clump stars of the Galaxy obtained in this work confirm the theoretical model of the Hipparcos clump by Girardi & Salaris (2001). This suggests that nearby clump stars are (in the mean) relatively young objects, reflecting mainly the near-solar metallicities developed in the local disk during the last few Gyrs of its history. We find iron group element to iron abundance ratios in clump giants to be close to solar.Comment: 9 pages, 7 figures, accepted for publication in MNRA

The Molonglo Galactic Plane Survey: I. Overview and Images

The first epoch Molonglo Galactic Plane Survey (MGPS1) is a radio continuum survey made using the Molonglo Observatory Synthesis Telescope (MOST) at 843 MHz with a resolution of 43" X 43" cosec |delta|. The region surveyed is 245 deg < l < 355 deg, |b| < 1.5 deg. The thirteen 9 deg X 3 deg mosaic images presented here are the superposition of over 450 complete synthesis observations, each taking 12 h and covering 70' X 70' cosec |delta|. The root-mean-square sensitivity over much of the mosaiced survey is 1-2 mJy/beam (1 sigma), and the positional accuracy is approximately 1" X 1" cosec |delta| for sources brighter than 20 mJy. The dynamic range is no better than 250:1, and this also constrains the sensitivity in some parts of the images. The survey area of 330 sq deg contains well over 12,000 unresolved or barely resolved objects, almost all of which are extra-galactic sources lying in the Zone of Avoidance. In addition a significant fraction of this area is covered by extended, diffuse emission associated with thermal complexes, discrete H II regions, supernova remnants, and other structures in the Galactic interstellar medium.Comment: Paper with 3 figures and 1 table + Table 2 + 7 jpg grayscales for Fig 4. Astrophysical Journal Supplement (in press) see also http://www.astrop.physics.usyd.edu.au/MGP