The broadcast automatic dependent surveillance (ADS-B) system is a new-generation air traffic control designed to avoid the waste of resources in secondary radars. establishment spaceborne ADS-B provides broad prospect for ionospheric tomography. In this paper, external observation information ionosphere obtained by measuring Faraday rotation angle, that is, total electron content (TEC). Tomogr...

Aurora Computed Tomography (ACT) is a method for retrieving the three-dimensional (3-D) distribution of the volume emission rate from monochromatic auroral images obtained simultaneously by a multi-point camera network. We extend this method to a Generalized-Aurora Computed Tomography (G-ACT) that reconstructs the energy and spatial distributions of precipitating electrons from multi-instrument...

The ionospheric F2-layer peak density (NmF2) and its height (hmF2) are of great influence on the shape of the ionospheric electron density profile Ne (h) and may be indicative of other physical processes within the ionosphere, especially those due to geomagnetic storms. Such parameters are often estimated using models such as the semiempirical international reference ionosphere (IRI) models or ...

As a member of the GPS Laboratory his research is focused on wide-area diierential GPS system design, analysis, and application. Mr.Hansen was a member of the technical staa at TASC, Inc. where he worked on DGPS, Loran-C, and Omega radionavigation systems before entering Stanford. He received his BSEE and MSEE from Worcester Polytechnic Institute. ABSTRACT We present a novel technique for estim...

We combine GPS/MET data from 29 occultations and IGS ground data collected from 160 stations around the world to perform stochastic tomography of the ionosphere with a 4×20×20 global grid of voxels extending from 200 to 650 km above the mean surface of the Earth. A correlation functional approach that limits the spatial high frequency content of the images is used, and a Kalman filter is applie...

ionospheric slab thickness is defined as the ratio of tec to maximum electron density of the f-region (nmf2), proportional to the square of the f2-layer critical frequency (fof2). it is an important parameter in that it is linearly correlated with scale height of the ionosphere, which is related to electron density profile. it also reflects variation of the neutral temperature. therefore, ionos...

In relation to satellite applications like global navigation satellite systems (GNSS) and remote sensing, the electron density distribution of the ionosphere has significant influence on trans-ionospheric radio signal propagation. In this paper, we develop a novel ionospheric tomography approach providing the estimation of the electron density’s spatial covariance and based on a best linear unb...

The estimation of transmitter location based on radio frequency reception at a single site has long been a challenge. The standard technique for location estimation has typically used an active local vertical transmitter (ionosonde) to characterize the local ionosphere for propagation path modeling. A technique that is totally passive and yields a more comprehensive estimate of the propagation ...

We compare TEC measurements from the NASA Radar Altimeter and DORIS instrument on board TOPEX/POSEIDON with GPS TEC estimates , and evaluate diierent GPS data analysis strategies. We verify that global tomographic GPS analysis using a voxel grid is well suited for ionospheric calibration of altimeters. We show that a 1-day t of 20-second-averaged NRA ionospheric correction data versus GPS tomog...

This paper highlights the important role played by the EISCAT radar for verification in the development of tomographic techniques to produce images of ionospheric electron density. A brief review is given of some of the stages in the application of tomographic reconstruction techniques to the ionosphere. Results are presented to illustrate the effectiveness of the method in imaging ionospheric ...