var antennas = 'antennas [ :{"id":"66175", "nom_com":"PARIS-8E-ARRONDISSEMENT", "nom_dept":"PARIS", "nom_reg":"ILE-DE-FRANCE", "generation":"2G", "emr_lb_systeme":"GSM 900", "coordonnes":["48.8663888889","2.32305555556"], "coord":"48° 51′ 59"N 2° 19′ 23"E"},{"id":"66176", "nom_com":"PARIS-8E-ARRONDISSEMENT", "nom_dept":"PARIS", "nom_reg":"ILE-DE-FRANCE", "generation":"4G", "emr_lb_systeme":"LTE 800", "coordonnes":["48.8663888889","2.32305555556"], "coord":"48° 51′ 59"N 2° 19′ 23"E"}]';

var antennas = 'antennas [ :{"id":"66175", "nom_com":"PARIS-8E-ARRONDISSEMENT", "nom_dept":"PARIS", "nom_reg":"ILE-DE-FRANCE", "generation":"2G", "emr_lb_systeme":"GSM 900", "coordonnes":["48.8663888889","2.32305555556"], "coord":"48° 51′ 59"N 2° 19′ 23"E"},{"id":"66176", "nom_com":"PARIS-8E-ARRONDISSEMENT", "nom_dept":"PARIS", "nom_reg":"ILE-DE-FRANCE", "generation":"4G", "emr_lb_systeme":"LTE 800", "coordonnes":["48.8663888889","2.32305555556"], "coord":"48° 51′ 59"N 2° 19′ 23"E"}]';
var antennasMap = JSON.parse(antennas);

for (var key in antennasMap) {
    console.log(key);
}