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The purpose of this paper is to design, build and test a low power high frequency (HF) transmitter that can be received by the Super Dual Auroral Radar Network (SuperDARN) radar installed at SANAE IV, the 4th South African National Antarctic Expedition Station. It is proposed that it may be possible to do propagation studies using the radar and the fixed frequency, ground-based HF transmitter beacon. Interpretation of the measurements can be used to study the ionosphere, especially Travelling Ionospheric Disturbances, which are signatures of atmospheric gravity waves.

In the absence of the actual deployment of the HF transmitter beacon in Antarctica, extensive simulations have been done to evaluate the expected performance of the transmitter in relation to the SuperDARN. A field trial has been executed between Hermanus (34.4241° S, 19.2247° E) and Pretoria (34.0558° S, 18.4589° E) in South Africa. In future, the beacon will be placed at the South Pole with its antenna radiating towards SANAE IV.

The HF transmitter conforms to the power and frequency stability requirements both during propagation tests conducted between Hermanus and Pretoria, as well as when the device was exposed to temperatures that ranged from +40°C to −45°C in a thermal chamber. Propagation in Antarctica is expected to differ from the field tests conducted due to the differences in density and dynamics of the polar ionosphere, compared to the mid-latitude ionosphere.

Space weather research, including forecasting atmospheric gravity waves and determining the expected electron density profile of the ionosphere, is of great scientific interest. The data received from the HF beacon can be used to study and characterize the ionosphere of the region between the South Pole and SANAE IV. Parameters of the ionosphere, such as electron density, geomagnetic storm effects, ionospheric motions and sky wave propagation paths will be better understood from analysing the signal received from this transmitter after it has been reflected and refracted by the ionosphere.

During the design of the Atlas I.C.B.M. it was considered necessary to conduct full‐scale combined structural loading and aerodynamic heating tests for the purpose of proving the ability of the nose adaptor and thrust barrel to withstand the combined effects of load and temperature. The following items were required to perform the tests: heating elements to radiate 450 sq. ft. of specimen area at a maximum rate of 10,000 B.T.U/sq. ft./hr., 1,500 KVA at 44 volts for six mins., controller, three variable pressure regulators for programming 3,000 lb./sq. in. hydraulic pressure to the loading cylinders, six‐channel programmer for varying heating and loading rates, a method for relating the capabilities of the equipment to the desired heat and load curves. Descriptions arc given of the heating equipment, heat controller, load controller, programmer, preliminary heat tests, preliminary load tests and test programmes as used by the Systems Test Laboratory of Convair‐Astronautics. As experience was gained by testing the need for preliminary tests was greatly reduced. The method described continues to be a valuable tool for performing full‐scale missile structural tests.

The International Ergonomics Association (IEA)'s definition of HF/E includes the following:Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimize human well-being and overall system performance … Organizational ergonomics is concerned with the optimization of sociotechnical systems, including their organizational structures, policies, and processes. (IEA Council, 2000)

A full size model of a Lynx helicopter's cockpit and rear fuselage fitted with a variety of advanced navigation and defence electronics equipment will be the central feature of the Racal Electronics exhibit at the Farnborough Air Show, 5–12 September, 1982 (Stands NN29 and R13).

A completely new, combined HF and VHF communications system has been developed by The Marconi Company, primarily for use in light aircraft and helicopters. This single system, type AD 1400, provides all the communications facilities which are necessary for a wide range of light aircraft.

A novel vision-based relative navigation system (VBRNS) plays an important role in aeronautics and astronautics fields, and the filter is the core of VBRNS. However, most of the existing filtering algorithms used in VBRNS are derived based on Gaussian assumption and disregard the non-Gaussianity of VBRNS. Therefore, a novel robust filtering named as cubature Huber-based filtering (CHF) is proposed and applied to VBRNS to improve the navigation accuracy in non-Gaussian noise case.

Under the Bayesian filter framework, the third-degree cubature rule is used to compute the cubature points which are propagated through state equation, and then the predicted mean and the associated covariance are taken. A combined minimum l₁ and l₂-norm estimation method referred as Huber’s criterion is used to design the measurement update. After that, the vision-based relative navigation model is presented and the CHF is used to integrate the line-of-sight measurements from vision camera with inertial measurement of the follower to estimate the precise relative position, velocity and attitude between two unmanned aerial vehicles. During the design of relative navigation filter, the quaternions are used to represent the attitude and the generalized Rodrigues parameters are used to represent the attitude error. The simulation is conducted to demonstrate the effectiveness of the algorithm.

By this means, the VBRNS could perform better than traditional VBRNS whose filter is designed by Gaussian filtering algorithms. And the simulation results demonstrate that the CHF could exhibit robustness when the system is non-Gaussian. Moreover, the CHF has more accurate estimation and faster rate of convergence than extended Kalman Filtering (EKF) in face of inaccurate initial conditions.

A novel robust nonlinear filtering algorithm named as CHF is proposed and applied to VBRNS based on cubature Kalman filtering (CKF) and Huber’s technique. The CHF could adapt to the non-Gaussian system effectively and perform better than traditional Gaussian filtering such as EKF.

APPLIED Technology, Middle East and European marketing and technical support representative of PF Industries Inc, will exhibit ground support equipment supplied to airlines worldwide.

THE FUEL system is straightforward, requiring little management. It has been kept simple, and contains few controls, thus ensuring a high degree of reliability. It operates on all fuels and additives approved for the engines.

Armstrong Siddeley Motors Ltd., of Coventry, announce that Mr W. F. Saxton, chief engineer, has been appointed a director of the Company.

A flexible stainless steel hose assembly is of special interest as it has been specifically designed for the transfer of liquid gases from mobile ground tankers to aircraft storage tanks.