Pixel-based event detection for tracking, hostile fire indication, glint suppression, and other applications

• Main Authors: Harris, Micky R, Boemler, Christian M, Beuville, Eric J, Costa, Juliette S, Massie, Mark A
• Format: Patent
• Language: English
• Published: 17.11.2020
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; CALCULATING; COLORIMETRY; COMPUTING; COUNTING; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; HANDLING RECORD CARRIERS; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASUREMENT OF NUCLEAR OR X-RADIATION; MEASURING; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; PRESENTATION OF DATA; RADIATION PYROMETRY; RADIO DIRECTION-FINDING; RADIO NAVIGATION; RECOGNITION OF DATA; RECORD CARRIERS; TESTING

A method includes repeatedly charging and discharging a capacitor, where the capacitor is charged based on illumination received at a pixel. The method also includes comparing a voltage stored on the capacitor with a reference voltage using a comparator. The method further includes incrementing or decrementing a first counter value of a first counter each time a comparator output indicates that the capacitor voltage has reached the reference voltage during a first period of time. The method also includes incrementing or decrementing a second counter value of a second counter each time the comparator output indicates that the capacitor voltage has reached the reference voltage during multiple smaller second periods of time within the first period of time. In addition, the method includes resetting the second counter for each second period of time and generating a pixel event indicator in response to the second counter value obtaining a value indicative of a bright intensity event.