Venus has no internal magnetic dynamo and thus its ionosphere and hot oxygen exosphere dominate the interaction with the solar wind. The solar wind at 0.72AU has a dynamic pressure that ranges from 4.5 nPa (at solar max) to 6.6 nPa (at solar min), and its flow past the planet produces a shock of typical magnetosonic Mach number 5 at the subsolar point. At solar maximum the pressure in the ionos...

As reported in [2,4,5], previous Stanford research has identified the potential for severe ionosphere spatial gradients to affect Local Area Augmentation System (LAAS) integrity. In previous work [1], real-time position-domain geometry screening was used to maximize LAAS availability in the presence of ionosphere anomalies by broadcasting an inflated value of σ vig so that the maximum-ionospher...

We present a study of statistical relationships between SAR arc intensities acquired by the Paci®c Northwest Laboratory Photometer Network during 1978±1988 and solar and geomagnetic activity indices Dst; F 10:7, and Kp by use of the method of multiple regression analysis. We found signi®cant correlations between intensity and all of the indices involved. In the present work we show for the ®rst...

An L band geosynchronous synthetic aperture radar (GEO SAR) differential interferometry system (D-InSAR) will be obviously impacted by the background ionosphere, which will give rise to relative image shifts and decorrelations of the SAR interferometry (InSAR) pair, and induce the interferometric phase screen errors in interferograms. However, the background ionosphere varies within the long in...

in this study, absorption of high frequency radio waves in the ionospheric plasma have beeninvestigated. the wave equation was obtained in terms of ionospheric parameters. the numerical values ofthe absorption have been calculated for 4 mhz, 4.5 mhz and 5 mhz waves. the necessary parameters forcalculation have been obtained using an international reference ionosphere (iri) model. the altitudina...

This paper describes the impact that extreme ionospheric spatial gradients occurring during severe ionosphere storms have on GNSS Ground Based Augmentation Systems (GBAS) and how the U.S. Local Area Augmentation System (LAAS) mitigates the integrity risk due to these events. Gradients in slant ionosphere delay of as large as 425 mm/km over baselines of 40 – 100 km have been observed in CONUS du...

Ionospheric delay effect is a critical issue that limits the accuracy of precise Global Navigation Satellite System (GNSS) positioning and navigation for single-frequency users, especially in mid- and low-latitude regions where variations in the ionosphere are larger. Kriging spatial interpolation techniques have been recently introduced to model the spatial correlation and variability of ionos...

This paper presents data from low-elevation satellites on 20 November 2003 in the Ohio region, the area of the largest validated gradients seen to date. As viewed by multiple CORS stations in central and northeastern Ohio, SVN 26 came into view around 2030 UT on this day, rose to an elevation angle of about 15 degrees just after 2100 UT, and set between 2135 and 2200 UT. This observation window...

This work addresses some of the key topics of space physics research recommended in the National Research Council 2003 report “A Decadal Research Strategy in Solar and Space Physics”, namely, the thunderstorm-driven electrodynamic coupling between the troposphere, mesosphere, lower ionosphere, and magnetosphere. Lightning-induced electron precipitation encompasses all of these regions, from atm...