Advances in aircraft-height estimation using distance-measuring equipment

The authors address the subject of aircraft geometric-height estimation, based on measurements from three distance-measuring equipment (DME) stations. A new improved height computation algorithm is presented, which is computationally efficient and mathematically tractable. The simple form of the new algorithm leads to easy derivation of analytic expressions for both the standard deviation and inherent systematic errors. Evaluation results are presented for representative conditions. The appropriate form of filtering algorithm is proposed for producing bias-free and more accurate height estimates