FIRST COMPLEMENTARY OBSERVATIONS BY IONOSPHERIC TOMOGRAPHY, THE EISCAT SVALBARD RADAR AND THE CUTLASS HF RADAR

Experimental results are presented from ionospheric tomography, the EI SCAT Svalbard radar and the CUTLASS HF radar. Tomographic measurements on 10 October 1996, showing a narrow, field-aligned enhancement in el ectron density in the post-noon sector of the dayside auroral zone, ar e related to a temporal increase in the plasma concentration observed by the incoherent scatter radar in the region where the HF radar indic ated a low velocity sunwards convection. The results demonstrate the c omplementary nature of these three instruments for polar-cap ionospher ic studies.