A processing system for an input device includes a sensor module coupled to first sensor electrodes and second sensor electrodes. The sensor module includes sensor circuitry and is configured to acquire mutual capacitive measurements between the first sensor electrodes and the second sensor electrodes, and acquire absolute capacitive measurements of the first sensor electrodes and the second sensor electrodes. The processing system further includes a determination module configured to determine a projection from the mutual capacitive measurements and a profile from the absolute capacitive measurements, and determine a low ground mass correction factor based on a good ground value, the projection, and the profile.