The Super Dual Auroral Radar Network (SuperDARN) has been operating as an international co-operative organization for over 10 years. The network has now grown so that the fields of view of its 18 radars cover the majority of the northern and southern hemisphere polar ionospheres. SuperDARN has been successful in addressing a wide range of scientific questions concerning processes in the magnetosphere, ionosphere,

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Continuous ground-based observations of ionospheric and magnetospheric regions are critical to the Geospace Environment Modeling (GEM) program. It is therefore important to establish clear intercalibrations between different ground-based instruments and satellites in order to clearly place the ground-based observations in context with the corresponding in situ satellite measurements. HF-radars operating at high latitudes are capable of observing very large spatial regions of the ionosphere on a nearly continuous basis. In this paper we report on an intercalibration study made using the Polar Anglo-American Conjugate Radar Experiment radars located at Goose Bay, Labrador, and Halley Station, Antarctica, and the Defense Meteorological Satellite Program (DMSP) satellites. The DMSP satellite data are used to provide clear identifications of the ionospheric cusp and the low-latitude boundary layer (LLBL). The radar data for eight cusp events and eight LLBL events have been examined in order to determine a radar signature of these ionospheric regions. This intercalibration indicates that the cusp is always characterized by wide, complex Doppler power spectra, whereas the LLBL is usually found to have spectra dominated by a single component. The distribution of spectral widths in the cusp is of a gcnc•any "" lrds. The •Jau•ta]] torm with .... •'-,.t. .... m•u•ouuun a la•mx of •la•,tral w,uth• in the LLBL is more like an exponential distribution, with the peak of the distribution occurring at about 50 m/s. There are a few cases in the LLBL where the Doppler power spectra are strikingly similar to those observed in the cusp. Paper number 94JA01481. 0148-0227/95/94JA-01481 $05.00 ground-based observations, submitted to Journal of Geophysical Research, 1994]. In this paper we report on the results of a study using satellite data and HF-radar data to perform a calibration of the radar data and determine the signatures of the cusp and the low-latitude boundary layer (LLBL). A significant controversy related to the cusp concerns the temporal structure of the cusp [Lockwood et al.In this paper, however, we shall not directly address this question. The results of the radar/DMSP intercalibration can be (and has been) interpreted as supporting both the steady cusp model and the pulsating cusp model. A resolution of this controversy will have to await further studies. The purpose of this paper is to establish more firmly the radar cusp/LLBL intercalibration [Baker et al., 1990b] with the DMSP observations. DMSP Identification of the Cusp and LLBL The satellite data we have chosen to use for the identification of the cusp and the LLBL is provided by the particle precipitation data from the DMSP F9 satellite [Hardy et al., 1985]. The work by Newell and his co-workers (Newell and Meng, 1988; Newell and Meng, 1989; Newell et al., 1989; Newell and Meng, 1992) has provided a firm base for the identification of the cusp and LLBL from these data. An important feature of this body of work has been the use of the ion precipitation data in ad...