Comparison of 3 Absolute Gravimeters Based on Different Methods for the e-MASS Project. - Anne Louchet-Chauvet; Sébastien Merlet; Quentin Bodart; Arnaud Landragin; Franck Pereira Dos Santos; Henri Baumann; Giancarlo D'Agostino; Claudio Origlia (IEEE Trans. Instrum. Meas., 2011)