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GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L14101, doi:10.1029/2004GL021954, 2005

First observations of SBAS/WAAS scintillations: Using collocated scintillation measurements and all-sky images to study equatorial plasma bubbles

B. M. Ledvina

School of Electrical and Computer Engineering, Cornell University, Ithaca, New York, USA


J. J. Makela

Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois, USA


Abstract

The first observations of amplitude scintillations on a Space Based Augmentation System (SBAS) satellite signal are presented. The scintillations occurred on the signal transmitted by a Wide Area Augmentation Satellite (WAAS) on 8–9 September 2004 from 2250–0045 LT. The GPS receiver that measured the scintillations is located on Haleakala, Hawaii (geomagnetic: 21.3°N, 271.4°E). With a maximum S 4 = 0.35, corresponding to a peak-to-peak SNR variation of 8 dB, the scintillations are relatively weak, which is to be expected for a site poleward of the equatorial anomaly during declining solar conditions. Using a collocated all-sky imager, features of the irregularity structuring in the equatorial plasma bubbles are resolved. The satellite signals scintillate when the ray path intersects the three main bubbles. The scintillation intensity tends to peak near the walls, and decreases slightly in the interior of the bubbles. In this case, the bubbles' leading (east) walls contain smaller-scale-size irregularities than the trailing (west) walls.

Received 17 November 2004; accepted 10 June 2005; published 16 July 2005.

Index Terms: 2403 Ionosphere: Active experiments; 2443 Ionosphere: Midlatitude ionosphere; 2494 Ionosphere: Instruments and techniques; 6979 Radio Science: Space and satellite communication.

Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 241886 bytes)

Citation: Ledvina, B. M., and J. J. Makela (2005), First observations of SBAS/WAAS scintillations: Using collocated scintillation measurements and all-sky images to study equatorial plasma bubbles, Geophys. Res. Lett., 32, L14101, doi:10.1029/2004GL021954.