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Sky noise measurement s with a dual polarization active dipole antenna. Didier C HARRIER S ubatech, Nantes, France Didier.charrier@subatech.in2p3.fr the CODALEMA collaboration http://codal e ma.in2p3.fr SUBATECH, Nantes Observatoire de Paris-Meudon Observatoire de Nançay LAL, Orsay
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Sky noise measurements with a dual polarization active dipole antenna Didier CHARRIER Subatech, Nantes, France Didier.charrier@subatech.in2p3.fr the CODALEMA collaboration http://codalema.in2p3.fr SUBATECH, Nantes Observatoire de Paris-Meudon Observatoire de Nançay LAL, Orsay ESEO, Angers LPSC, Grenoble LPCE, OrleansLAOB, Besançon (FRANCE) WORKSHOP Radio@auger, January 14 and 15 2008, subatech Nantes
Active dipole antenna used for CODALEMA Dipole antenna Total arm length = 1.21m Antenna height = 1m didier.charrier@subatech.in2p3.fr WORKSHOP Radio@auger, January 14 and 15 2008, subatech Nantes
Crossed polarised active dipole antenna Same preamplifier as the CODALEMA antenna Dual polarization V-shape radiator made of electric wires Total arm length = 3.22m Antenna height = 1.40m didier.charrier@subatech.in2p3.fr WORKSHOP Radio@auger, January 14 and 15 2008, subatech Nantes
Measurement setup Spectrum Analyser FSH LNA, 36dB 15m cable 24-82MHZ filter LNA, 36dB 12V battery Dual polar active antenna under test -Measurement performed in a rural area at Vairé in Vendée (100km south of Nantes) -Dual polarization active antenna -Handheld spectrum analyzer R&S FSH -24/82MHz passband filter to avoid intermodulation created spectrum analyzer -12V battery to supply the active antenna didier.charrier@subatech.in2p3.fr WORKSHOP Radio@auger, January 14 and 15 2008, subatech Nantes
North South and East West spectrum Accumulation of 17 sweep during one day LST didier.charrier@subatech.in2p3.fr WORKSHOP Radio@auger, January 14 and 15 2008, subatech Nantes
Galactic noise variations for few bands ~2.7dB ~2.3dB ~2.7dB ~2.5dB didier.charrier@subatech.in2p3.fr WORKSHOP Radio@auger, January 14 and 15 2008, subatech Nantes
Galactic noise variation for the 73/77MHz band ~2.5dB -The measured galactic noise variation is about2.5dBin both polarisations from 30MHZ to 80MHZ -This experiment should be performed with an automatic testbench to increase the statistics, and without passband filtering. didier.charrier@subatech.in2p3.fr WORKSHOP Radio@auger, January 14 and 15 2008, subatech Nantes
Measurement versus simulation Computed sky noise response with a NEC2 simulator and this sky temperature data didier.charrier@subatech.in2p3.fr WORKSHOP Radio@auger, January 14 and 15 2008, subatech Nantes