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  • Author or Editor: H. M. De Jong x
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H. M. De Jong


The position of a pilot balloon or any other airborne target which is followed by two theodolites is usually computed by means of the known baselength (i.e., the distance between the two theodolite stations) and three observed angle readings. It is to be noted, however, that four angle readings are available. In order to obtain an optimum estimation of the target's location the theory of adjustment of observations should be applied. With this method the estimation of the location is based on making the magnitude of the (root mean square) error a minimum. The method is particularly suitable for high speed electronic computers. The error analysis makes it possible to give some valuable hints in planning specific experiments with two optical or radio theodolites.

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H. M. de Jong


The present system of evaluating upper winds by means of radar/radio tracking of pilot and radiosonde balloons is in its most general form to be considered as an overdetermined observation system. The redundancy of information in such systems may be used to improve the overall precision of measurement by applying the well-known theory of adjustment of observations. In this paper a scheme for computation is presented, not only for the case of a flat earth, but also for the case including the effect of the earth's curvature. The scheme is particularly feasible for implementation in practice by means of electronic data processing.

The proposed scheme has the advantage that the numerical process also incorporates the conventional modes of operation. Apart from an adjustment procedure a simple smoothing process is described which depends on the accuracy attainable by the measuring technique. This effectuates a partial separation of the instrumental errors from real wind fluctuations. Some numerical data give an impression of the gain in accuracy and the effect of a certain amount of smoothing.

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