Intrepid digital microwave. A new approach to bistatic radar

Southwest Microwave, Inc. (SMI) introduced the world's first commercially viable bistatic microwave intrusion detection sensor in 1971. Bistatic microwave has become the paradigm for high security perimeters, and SMI products have become industry standards. With the introduction of the Intrepid Digital Microwave, SMI brings the latest in Digital Signal Processing (DSP) and power and data networking to this proven sensor technology     

Optimum spectral bands for land cover discrimination

An experiment was undertaken to select the optimum spectral bands for the discrimination of land use/cover for proposed Indian Remote Sensing Satellite. A feature selection method was used for the discrimination analysis on the multiband data collected by Bendix 11-channel Modular Multiband Scanner over Tirupati test site of Chittoor district, Andhra Pradesh, South India. Of the various combinations of bands analysed, the optimum combination of four bands was defined as that one which provided the greatest divergence distances to discriminate the specific land covers in the test sites. On the basis of the above studies the optimum bands so chosen are 0.49–0.54 μm, 0.62–0.66 μm, 0.66–0.70 μm and 0.77–0.86 μm.     

Two-dimensional convection in liquid layer related to crystal growth techniques in space

In this paper, the Marangoni convection including buoyancy convection in two-dimensional fluid model was investigated experimentally and theoretically. The transparent liquid in the test cell was heated and cooled under various conditions. The fluid flow driven by surface tension and by buoyancy force was visualized and measured. The flow patterns, velocity distributions and temperature field were obtained and they were compared with the results of the numerical solutions. The effect of the configuration and the convection in microgravity on crystal growth was discussed. The temperature field of the crystallizing surface was predicted.     

Selection of spectral bands for Indian remote sensing satellite (IRS)

Indian Space Research Organisation (ISRO) plans to launch a Remote Sensing Satellite around 1985 for acquiring resources information in the visible and near infrared region. For this a number of projects under Joint Experiments Program (JEP) were taken up between ISRO and various departments under Government of India to define the mission parameters including the spectral bands. This paper presents the results obtained in the selection of spectral bands and their widths for IRS program.     

Satellites for the study of ocean primary productivity

Estimates of global marine primary productivity are currently based upon the ¹⁴C method for determining rates of plankton photosynthesis and upon the relatively sparse data available using shipboard sampling techniques. With recent advances in remote sensing and in multiplatform (ship, aircraft, and satellite) sampling strategies, it is now possible to significantly lower the variance in estimates of phytoplankton abundance and of population growth rates.Multiplatform sampling strategies are essential to assess the mean and variance of phytoplankton biomass on a regional or on a global basis. The relative errors associated with shipboard and satellite estimates of phytoplankton biomass and primary productivity, as well as the increased statistical accuracy now possible from the utilization of contemporaneous data from both sampling platforms, are discussed. It is shown that one of the more exciting and potentially useful aspects of oceanographic research today is our new ability to view large areas of the ocean synoptically.     

The use of reflection spectra in recognition of crops

The use of reflection spectra to recognize crops has been discussed. A technique to exclude the contribution to SBC by soil and weeds has been suggested.     

Sensitivity on nonequilibrium chemical systems to gravitational field

We note that far-from-equilibrium chemical systems can respond very sensitively to gravity. The response could be in selection of possible structures or in the formation of propagating bands. In these cases the sensitivity is characterized by the factor $\text{(E}{}_{\mathrm{g}}\text{/kT)}{}^{\mathrm{<mtext>1</mtext><mtext>n</mtext>}}$, where n=2 or 3, E_g the interaction energy, k the Boltzmann constant and T, the temperature. Also, taking the thermodynamic fluctuations into account, we obtain the theoretical limit for the minimum field strength measurable by such systems.     

The Io-control of Jupiter's decametric radiation: The Alfvén wave model

Geometrical considerations based on a conical sheet model of the observed DAM sources show that DAM is generated on field lines in the active longitude sector φ ～ 200 ± 90°. We show how Io excites Alfvén waves and calculate the propagation of these waves through the inhomogenous torus and magnetosphere. The power flux at high latitudes is largest at two longitudes which are seen as the B₁, B₂, A and C sources. We also discuss the parallel electric field accompanying the Alfvén wave pulses and show that at high latitudes electrons can be accelerated to energies in excess of 1000 eV. It is suggested that these current carrying electrons excite ion-cyclotron, upper and lower-hybrid electrostatic waves which may all play crucial roles in the generation of DAM.     

Examination of a smallest CELSS (microcosm) through an individual-based model simulation.

Research of the effect of space environment on an ecosystem consisting of plants and animals is essential when they are to be positively used in space. Although there have been experiments on various organisms under space environment in the past, they mainly studied the effect of space environment on an individual organism or a single species. Microcosm is drawing attention as an experimental material of an ecosystem consisting of multiple species. The object in this research is to understand the nature of this network system called ecosystem. Thus, a mixed microorganism culturing system consisting of three types of microorganisms which form a minimum food chain system as a closed ecosystem (chlorella as the producer, bacteria as the decomposer, and rotifer as the consumer) was taken for the subject, on which to research the universal characteristics of ecosystems. From the results of experiments under the terrestrial environment, formation of colonies, which is an ecological structure, has been observed at its mature stage. The organisms form an optimal substance circulation system. Therefore, formation of colonies in simulation models is important. Many attempts have been made to create ecosystem models. For example, the Lotka-Volterra model forms a simultaneous equation with the differential equation expressing predator and prey relationship and many numerical calculations have been conducted on various ecosystems based on expanded L-V models. Conventionally, these top-down methods have been used. However, since this method only describes the average concentration of organisms that are distributed uniformly throughout the system and cannot express the spatial structure of the system, it was difficult to express ecosystem structures like colonies and density distributions. In actual ecosystems, there is heterogeneity in the number of individuals and in substance density, and this is thought to have great significance in ecosystems. Consequently, an individual-based model was used that applies rules to predator-prey relationship, suppression, production, self suppression, etc., of each species. It enabled the emergence of the overall system only by its local rules, and it was possible to reproduce colony generation. In addition, the transition and the ratio of populations for each species match well with experimental results.     

Choosing software and replacing ATE: lessons learned

When tasked to ensure the Minuteman Intercontinental Ballistic Missile system remains fully operational and supportable through 2020, the Air Force realized that the support capability of its legacy automated test system for the operational ground support electronics subsystem would need to be completely replaced. The legacy test system, while fully operational, was rapidly becoming non-supportable. Unless replaced with new hardware and upgraded test program sets, the needed long-term support could not be provided to the weapon system. To address this issue within the scope of available program funding constraints, the Air Force selected an approach of combining the technical and programmatic expertise of the weapon system prime contractor, the program control responsibilities of the weapon system Program Office, and the technical capability of an Air Force technical organization. The program was divided into two phases: a prototype phase and a production/rehost phase. This paper gives an overview of the program and presents valuable lessons learned during the prototype phase.