The solar diameter and oblateness measured by the solar disk sextant on the 1992 September 30 balloon flight

1994 ◽  
Vol 427 ◽  
pp. 1048 ◽  
Author(s):  
S. Sofia ◽  
W. Heaps ◽  
L. W. Twigg
Keyword(s):  
Solar Disk ◽  
Balloon Flight ◽  
Solar Diameter

Processing Method Effects on Solar Diameter Measurements: Use of Data Gathered by the Solar Disk Sextant

Solar Physics ◽  
2008 ◽  
Vol 247 (2) ◽  
pp. 225-248 ◽  
Author(s):  
D. Djafer ◽  
G. Thuillier ◽  
S. Sofia ◽  
A. Egidi
Keyword(s):  
Solar Disk ◽  
Processing Method ◽  
Solar Diameter ◽  
Use Of Data ◽  
Method Effects

OVERCOMING BLACK DROP EFFECT IN HIGH RESOLUTION ASTROMETRY: THE CASE OF SEA SUNSETS

2011 ◽  
Vol 20 (10) ◽  
pp. 2009-2012
Author(s):  
COSTANTINO SIGISMONDI
Keyword(s):  
High Resolution ◽  
Solar Disk ◽  
Contact Time ◽  
Diffraction Limit ◽  
Residual Error ◽  
Sea Surface ◽  
Analytical Function ◽  
The Sun ◽  
Solar Diameter ◽  
First Contact

Planetary transits on the Sun have been used to recover past values of the solar diameter. These results, as in 1832 Mercury transit, are different when different observers and instruments are considered, because of the black drop phenomenon. Sunsets above sea surface (near-zero almucantarat transit) show it clearly: the first contact between solar disk and the horizon is anticipated by luminous connections. The last instant of light is independent on detector's optics when the atmosphere is clear. The first contact time is obtained by fitting to data the analytical function of the intersection between Sun and sea horizon. This correction overcomes the black drop effect almost completely, the last residual error remains below the diffraction limit, as demonstrated by sunset timings.

High-Precision Measurements of the Solar Diameter and Oblateness by the Solar Disk Sextant (SDS) Experiment

Solar Physics ◽  
2006 ◽  
Vol 235 (1-2) ◽  
pp. 407-418 ◽  
Author(s):  
A. Egidi ◽  
B. Caccin ◽  
S. Sofia ◽  
W. Heaps ◽  
W. Hoegy ◽  
...  
Keyword(s):  
High Precision ◽  
Solar Disk ◽  
Precision Measurements ◽  
Solar Diameter

Preliminary results of a balloon flight of the solar disk sextant

1992 ◽  
Vol 389 ◽  
pp. 447 ◽  
Author(s):  
E. Maier ◽  
L. Twigg ◽  
S. Sofia
Keyword(s):  
Solar Disk ◽  
Balloon Flight ◽  
Preliminary Results

High Altitude Balloon Flight Test of the GRAD Experiment

1990 ◽  
Author(s):  
Robert J. Hicks ◽  
David H. Jenkins
Keyword(s):  
High Altitude ◽  
Flight Test ◽  
Balloon Flight

The Heights of Solar Radio Sources at 1424 MHz and 696 MHz

1969 ◽  
Vol 1 (5) ◽  
pp. 192-194 ◽  
Author(s):  
D. G. Cole ◽  
R. F. Mullaly
Keyword(s):  
Solar Activity ◽  
High Resolution ◽  
Solar Disk ◽  
Previous Investigation ◽  
Solar Radio ◽  
Radio Sources ◽  
Grating Interferometer ◽  
Maximum Solar Activity

The heights of solar radio sources at 1424 MHz and 696 MHz have been measured during the years 1965 and 1966. Solar activity at this time was near minimum. The number of radio sources appearing on the solar disk rarely exceeded three at any time and it thus was possible to resolve the majority of these with a high resolution grating interferometer. Many of the previous height measurements at these frequencies have been made near times of maximum solar activity and the confusion of sources within the beam has limited their accuracy. The number of sources studied here is quite considerably higher than in any previous investigation at these frequencies, and the period of observation has been continuous.

Variability of the solar diameter

1988 ◽  
Vol 8 (7) ◽  
pp. 119-128 ◽  
Author(s):  
Philippe Delache
Keyword(s):  
Solar Diameter

The spectra of near-vertical structures on the solar disk

Solar Physics ◽  
1972 ◽  
Vol 27 (1) ◽  
pp. 27-33 ◽  
Author(s):  
O. R. White
Keyword(s):  
Solar Disk
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