Comparison of the fixing accuracy of single-station locators and triangulation systems assuming ideal shortwave propagation in the ionosphere

Single-station locator fixing errors are calculated from a formula derived in the paper and compared with analogous errors arising in horizontal triangulation systems. It is assumed that single-hop wave propagation takes place and that the errors in the azimuth, elevation and virtual height of reflection are unbiased, normally distributed, mutually independent and small. The RMS error, which can be derived from the error ellipse, is used for errors comparison. If all the angular errors have the same standard deviation and if the height error is negligible, SSLs are superior at long ranges unless a very long triangulation baseline is available. Empirical fixing-error data, obtained from an HF Doppler SSL, were in good agreement with the values given by the formula