The Nancay Decametric Array is a Beautiful Instrument, in nearly daily use since the late 1970s.
It has 144 conical spirals (conical helices, Tee Pees), split into two side by side arrays for right and left circular polarizations. The geometrical area is about 8000 meter^2.
The 72 antennas (for each polarization) are grouped in 8 sets of 9. The phase of each 9 antenna group is adjusted in steps of 45 degrees by selecting 6 out of the 8 spirals in each antenna. The time delay of the output for each of the 8 sets is also adjusted from time to time, as needed by the pointing.
The abbreviations del and ph indicate the times of delay and phase changes.
Many thanks to the Taxpayers of France, and the Nancay Decametric Array Team at the Nancay Radio Astronomy Station of Paris Observatory.
130321 Non-Io-A below
130324 Io-A below
130307 non-Io-A below , pure right circular polarization
It has 144 conical spirals (conical helices, Tee Pees), split into two side by side arrays for right and left circular polarizations. The geometrical area is about 8000 meter^2.
The 72 antennas (for each polarization) are grouped in 8 sets of 9. The phase of each 9 antenna group is adjusted in steps of 45 degrees by selecting 6 out of the 8 spirals in each antenna. The time delay of the output for each of the 8 sets is also adjusted from time to time, as needed by the pointing.
The abbreviations del and ph indicate the times of delay and phase changes.
Many thanks to the Taxpayers of France, and the Nancay Decametric Array Team at the Nancay Radio Astronomy Station of Paris Observatory.
130321 Non-Io-A below
130324 Io-A below130307 non-Io-A below , pure right circular polarization