Sky noise measurements with a dual polarization active dipole antenna WORKSHOP January 14 and , subatech Nantes Didier CHARRIER Subatech, Nantes, France the CODALEMA collaboration SUBATECH, Nantes Observatoire de Paris-Meudon Observatoire de Nançay LAL, Orsay ESEO, Angers LPSC, Grenoble LPCE, Orleans LAOB, Besançon (FRANCE)

WORKSHOP January 14 and , subatech Nantes 2 Active dipole antenna used for CODALEMA Dipole antenna Total arm length = 1.21m Antenna height = 1m

WORKSHOP January 14 and , subatech Nantes 3 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

WORKSHOP January 14 and , subatech Nantes 4 Measurement setup -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 LNA, 36dB Dual polar active antenna under test 24-82MHZ filter 15m cable Spectrum Analyser FSH 12V battery

WORKSHOP January 14 and , subatech Nantes 5 North South and East West spectrum Accumulation of 17 sweep during one day LST

WORKSHOP January 14 and , subatech Nantes 6 Galactic noise variations for few bands ~2.3dB ~2.7dB ~2.5dB ~2.7dB

WORKSHOP January 14 and , subatech Nantes 7 Galactic noise variation for the 73/77MHz band -The measured galactic noise variation is about 2.5dB in both polarisations from 30MHZ to 80MHZ -This experiment should be performed with an automatic testbench to increase the statistics, and without passband filtering. ~2.5dB

WORKSHOP January 14 and , subatech Nantes 8 Measurement versus simulation Computed sky noise response with a NEC2 simulator and this sky temperature data