Capacitive sensor for detecting, locating the presence of, assessing the floor area of and/or tracking the activity of a person and/or of an object, said sensor including: - a first layer comprising at least one first electrode (E 1i, i∈[1,N]) running in a first direction; - a second layer comprising at least one second electrode (E 2j, j∈[1,M]) running in a second direction; wherein the first direction is different from the second direction, and wherein the first layer is electrically insulated from the second layer, said sensor further including: - an electronic driver module configured: • to independently apply a voltage to each of the electrodes (E 1i, E 2j), including at least one zero voltage to at least one of said electrodes (E 1i, E 2j); and • to measure the electric charges that have built up on each electrode (E 1i, E 2j), characterized in that said sensor further includes: - a computer processing module configured to analyse the spatial distribution of the variations in the charges measured for each of said electrodes (E 1i, E 2j) by determining: • information that is dependent on the coupling to ground of a first measurement electrode from among the at least one first electrode (E 1i) if the voltage applied to the first measurement electrode is nonzero, said first measurement electrode being within the first layer; and, according to the determined information that is dependent on the coupling to ground, by determining: • information that is independent of the coupling to ground of a second electrode from among the at least one second electrode (E 2j) if the voltage applied to the second measurement electrode is zero and the voltage applied to the first measurement electrode is nonzero, said second measurement electrode being within the second layer, so as to detect, to locate the presence of, to assess the floor area of and/or to track the activity of a person and/or of an object. - a first layer comprising at least one first electrode (E 1i, i∈[1,N]) running in a first direction; - a second layer comprising at least one second electrode (E 2j, j∈[1,M]) running in a second direction; - an electronic driver module configured: • to independently apply a voltage to each of the electrodes (E 1i, E 2j), including at least one zero voltage to at least one of said electrodes (E 1i, E 2j); and • to measure the electric charges that have built up on each electrode (E 1i, E 2j), characterized in that said sensor further includes: • to independently apply a voltage to each of the electrodes (E 1i, E 2j), including at least one zero voltage to at least one of said electrodes (E 1i, E 2j); and • to measure the electric charges that have built up on each electrode (E 1i, E 2j), characterized in that said sensor further includes: - a computer processing module configured to analyse the spatial distribution of the variations in the charges measured for each of said electrodes (E 1i, E 2j) by determining: • information that is dependent on the coupling to ground of a first measurement electrode from among the at least one first electrode (E 1i) if the voltage applied to the first measurement electrode is nonzero, said first measurement electrode being within the first layer; and, according to the determined information that is dependent on the coupling to ground, by determining: • information that is independent of the coupling to ground of a second electrode from among the at least one second electrode (E 2j) if the voltage applied to the second measurement electrode is zero and the voltage applied to the first measurement electrode is nonzero, said second measurement electrode being within the second layer, • information that is dependent on the coupling to ground of a first measurement electrode from among the at least one first electrode (E 1i) if the voltage applied to the first measurement electrode is nonzero, said first measurement electrode being within the first layer; • information that is independent of the coupling to ground of a second electrode from among the at least one second electrode (E 2j) if the voltage applied to the second measurement electrode is zero and the voltage applied to the first measurement electrode is nonzero, said second measurement electrode being within the second layer,