A sensor system, method, and computer program product for determining physical characteristics of individual plants within a row located in an agricultural environment is provided. Embodiments of the present invention include, but are not limited to, a sensor assembly including a plurality of emitters and a corresponding plurality of receivers disposed substantially opposite one another such that the receivers may receive a plurality of signals emitted by said emitters to generate a binary profile image of each plant within a row of plants positioned along a row axis. Embodiments of the present invention also include supplementary sensors for determining other plant characteristics including leaf pattern and plant location along the row axis. The method and computer program product embodiments of the present invention may also differentiate selected plants of interest from invasive or weed species using the outputs of the sensor device of the present invention.