[1] Radio occultation remote sensing of the Earth’s atmosphere by use of GPS encounters problems in the moist lower troposphere (planetary boundary layer). The negative errors in retrieved refractivity (bias) may not be explained by the horizontal inhomogeneity in refractivity. In part, these errors can be attributed to the use of signal tracking algorithms inappropriate for the complicated str...

Introduction: Since the late 1980s, stellar occultations have provided snapshots of the Pluto system and specifically of Pluto’s atmospheric evolution. The lower atmosphere, below roughly half-light level in an occultation light curve, has changed distinctly over time (e.g. [1, 2]). Theorized explanations for the lower atmospheric structure include a steep thermal gradient and/or extinction, th...

Occultation and microlensing are different limits of the same phenomena of one body passing in front of another body. We derive a general exact analytic expression which describes both microlensing and occultation in the case of spherical bodies with a source of uniform brightness and a non-relativistic foreground body. We also compute numerically the case of a source with quadratic limb-darken...

[1] The Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC)/Formosa Satellite 3 (FORMOSAT-3) is a six-satellite radio occultation mission that was launched in mid-April, 2006. The close proximity of the COSMIC satellites provides a unique opportunity to estimate the precision of the radio occultation remote sensing technique from closely collocated occultations (<10 k...

GPS-to-low-earth-orbiting (LEO) radio occultation (RO) geometries are designed for vertical-plane measurements. Reconstruction of atmospheric and ionospheric pro…les is facilitated by the planar geometry. Interpreting scintillation that develops over the extended propagation path is more challenging. The point of closest approach is a natural reference for reporting scintillation on occultation...

During the past decade, researchers have been working to develop methods for the assimilation of Global Positioning System (GPS) radio occultation data into numerical weather prediction (NWP) models. Until recently, two strategies have received the most attention: 1) assimilation of the retrieved bending angle profiles, and 2) assimilation of the retrieved refractivity profiles. The assimilatio...

We have observed a stellar occultation of GSC5249-01240 by Saturn's north polar region on November 20, 1995 from NASA's Infrared Telescope Facility (IRTF). This is the first recorded occultation by the polar region of a giant planet. The occulted region extends 88 km in vertical height and 660 km in horizontal length, over a region from 82.5 to 85 degrees in planetocentric latitude and from 20 ...

A radio holographic approach, developed by Pavelyev (1998), Hocke et al. (1999), Igarashi et al. (2000), is applied to observation of wave phenomena in the upper atmosphere using Global Positioning System "Microlab-l" satellite (GPS/MET) radio occultation data. In the current state the radio holography approach uses the radar focused synthetic aperture principle to obtain high spatial resolutio...

On 1995 August 21, Saturn’s moon Titan occulted the 13th magnitude star GSC5254-00997. The predawn event was observed at 2.3 μm with the NASA 3.0-m Infrared Telescope Facility. We measured the average atmospheric scale height between latitudes 50◦S and 67◦S by fitting isothermal models to the immersion portion of the occultation lightcurve. Within the altitude range of 300 to 500 km, we find an...

An Earth orbiting detector sensitive to gamma ray photons will see step-like occultation features in its counting rate when a gamma ray point source crosses the Earth's limb. This is due to the change in atmospheric attenuation of the gamma rays along the line of sight. In an uncollimated detector, these occultation features can be used to locate and monitor astrophysical sources provided their...