Corrected Calculation of Star Trails Caused by Differential Atmospheric Refraction

2006 ◽  
Author(s):  
Eric Harvey Richardson
Keyword(s):  
Atmospheric Refraction

On an Inaccuracy (having its greatest value about 1″) in the usual method of computing the Moon's Parallax.

1857 ◽  
Vol 3 ◽  
pp. 292-293
Author(s):  
Edward Sang
Keyword(s):  
Usual Method ◽  
Zenith Distance ◽  
The Moon ◽  
Atmospheric Refraction ◽  
Usual Operation

When, as in the usual operation, the moon's observed zenith distance is corrected for the effects of atmospheric refraction, the zenith distance so obtained is that of the rectilineal part of the ray of light between the planet and the upper surface of the air; and on applying that correction, as at the Observatory, we do not obtain the direction of the moon as it would have been seen if there had been no atmosphere, but that of a line drawn parallel to the first part of the ray, and therefore passing below the moon.

scholarly journals Movement of the Ward Hunt Ice Shelf, Ellesmere Island, N.W.T., Canada

1971 ◽  
Vol 10 (59) ◽  
pp. 211-225 ◽  
Author(s):  
E. Dorrer
Keyword(s):  
Power Flow ◽  
Field Work ◽  
Ellesmere Island ◽  
Ice Shelf ◽  
Surface Layers ◽  
Atmospheric Refraction ◽  
Near Surface ◽  
Angle Measurements ◽  
Ice Velocity ◽  
Ice Forces

AbstractThe movement at a marginal location on the Ward Hunt Ice Shelf, northern Ellesmere Island, was determined by repeated survey measurements with theodolite and geodimeter. The purpose and duration of the field work, and reduction of the observational data are described, and the resulting mean ice velocity of 0.53 m year-1is discussed. Strain-rates of a 1 km by 1 km deformation figure are determined. The parametersnandBof Glen’s power flow law are determined by using the equations given by Nye and Weertman. The results are compared with experimental data. Computed ice stresses show that the “ridge-and-trough" structure on the ice shelf surface is not originated by internal ice forces. The elevations of all survey markers have been determined from vertical-angle measurements, and the peculiarities of atmospheric refraction in near-surface layers are discussed.

scholarly journals Effects of Atmospheric Refraction on an Airborne Weather Radar Detection and Correction Method

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Lei Wang ◽  
Ming Wei ◽  
Tao Yang ◽  
Ping Liu
Keyword(s):  
Weather Radar ◽  
Weather Conditions ◽  
Refraction Index ◽  
Correction Method ◽  
Propagation Path ◽  
Radar Detection ◽  
Atmospheric Refraction ◽  
Radar Beam ◽  
Fitting Method ◽  
Flight Parameters

This study investigates the effect of atmospheric refraction, affected by temperature, atmospheric pressure, and humidity, on airborne weather radar beam paths. Using three types of typical atmospheric background sounding data, we established a simulation model for an actual transmission path and a fitted correction path of an airborne weather radar beam during airplane take-offs and landings based on initial flight parameters and X-band airborne phased-array weather radar parameters. Errors in an ideal electromagnetic beam propagation path are much greater than those of a fitted path when atmospheric refraction is not considered. The rates of change in the atmospheric refraction index differ with weather conditions and the radar detection angles differ during airplane take-off and landing. Therefore, the airborne radar detection path must be revised in real time according to the specific sounding data and flight parameters. However, an error analysis indicates that a direct linear-fitting method produces significant errors in a negatively refractive atmosphere; a piecewise-fitting method can be adopted to revise the paths according to the actual atmospheric structure. This study provides researchers and practitioners in the aeronautics and astronautics field with updated information regarding the effect of atmospheric refraction on airborne weather radar detection and correction methods.

scholarly journals Differential measurement of atmospheric refraction using a telescope with double fields of view

2015 ◽  
Vol 15 (10) ◽  
pp. 1742-1750 ◽  
Author(s):  
Yong Yu ◽  
Jian-Jun Cao ◽  
Zheng-Hong Tang ◽  
Hao Luo ◽  
Ming Zhao
Keyword(s):  
Atmospheric Refraction ◽  
Differential Measurement

scholarly journals ATMOSPHERIC REFRACTION

2014 ◽  
pp. 116-144
Author(s):  
Robert Stawell Ball
Keyword(s):  
Atmospheric Refraction
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