Systematic errors in whistler extrapolation—2. Comparison of methods

Middle and High Latitude Whistlers Observed Simultaneously in a Low Latitude Station at Agra.

“…The choice of the diffusive equilibrium model for the present analysis is based on the consideration that it has been found to be very suitable for the analysis of the mid latitude whistlers. In this model, the theoretical whistlers are found to be similar to the experimentally observed whistlers (Stuart, 1977b) and also the errors in ionospheric parameters determined from this model are much less as compared to other models (Park, 1972). Now, the question arises whether the curve fitting technique of Tarcsai (1975) which was developed basically for ducted whistlers can be applied in the case of nonducted PL mode whistlers.…”

“…In this model, the theoretical whistlers are found to be similar to the experimentally observed whistlers (Stuart, 1977b) and also the errors in ionospheric parameters determined from this model are much less as compared to other models (Park, 1972). Now, the question arises whether the curve fitting technique of Tarcsai (1975) which was developed basically for ducted whistlers can be applied in the case of nonducted PL mode whistlers. In order to answer this it may be mentioned here that the PL mode whistlers not only follow the Eckersley law strictly but they also produce the travel times and wave normal directions which are characteristics of ducted propagation.…”

“…The value of foF2 was taken to be 7.8 MHz which was the same as that taken by Chauhan and Singh (1992). A diffusive equilibrium model similar to that adopted by Park (1972), Tarcsai (1975, and Chauhan and Singh (1992) was employed which was represented at a height of 1000 km by an electron density of 103 electronslcm3, O+ = 90%, H+ = 8% and He+ = 2%, and temperature of 1000°K. The value of the Marquardt's parameter (FA) was taken to be 10-2 for the analysis of all the whistlers except for the poorly defined short trace whistler of dispersion 67 sect/2 in which case the value is taken to be 1.…”

“…The value of the Marquardt's parameter (FA) was taken to be 10-2 for the analysis of all the whistlers except for the poorly defined short trace whistler of dispersion 67 sect/2 in which case the value is taken to be 1. This is done following the suggestion of Tarcsai (1976) that in the case of short trace and poorly defined whistlers the value of FA may be taken between 10-1 and 101. As shown in Fig.…”

“…It is worthwhile to mention here that although there are a number of nose extension methods developed to analyse the middle and high latitude whistlers (Dowden and Allcock, 1971;Bernard, 1973;Corcuff and Corcuff, 1973;Ho and Bernard, 1973;Rycroft and Mathur, 1973;Smith et al, 1975;Stuart, 1977a) the one given by Tarcsai (1975) has some advantages over the others. For example, it can be applied for the analysis of low latitude whistlers whose propagation paths are greater than L = 1.4 and also the errors in the analysis of mid latitude whistlers particularly related to equatorial electron density and total electron content are much low.…”