A comparison of equatorial electron content in the Indian and American longitudes

Total electron content (TEC) measurements taken at the magnetically equatorial stations located at Ootacamund, India and Huancayo, Peru by the group delay technique from radio beacon signals transmitted from the ATS 6 geostationary satellite show excellent agreement, though these stations are at widely different longitudes and are at nearly opposite geographic latitudes. Data from both stations were taken during the solar minimum period 1975-1976. The equivalent slab thickness, the ratio TEC/N<SUB>max</SUB>, also indicated similar F region profile shape in the two longitude sectors. The standard deviation of equatorial daytime TEC is significantly smaller than at other latitudes