RPC application in muography and specific developments

Abstract: Muography is an imaging technique for large and dense structures as volcanoes or nuclear reactors using atmospheric muons. We applied this technique to the observation of the Puy de D^ome, a volcano 2 km wide close to Clermont-Ferrand, France. The detection is performed with a 1m$\times$1m$\times$1.80m telescope made of 4 layers of single gap glass-RPCs operated in avalanche mode. The 1 cm$^2$ pad readout uses the Hardroc2 ASICs. The three data taking campaigns over the last three years showed that a RPC detector can be operated in-situ with good performances. Further developments to decrease the gas and power consumption and to improve the position and timing resolution of the detector are ongoing.