A new operation mode for depth-focused high-sensitivity ToF range finding

TL;DR

This paper presents PC-ToF, a novel depth sensing method that enhances local depth resolution around specific depths using pulsed correlation techniques, suitable for low-power applications.

Contribution

Introduction of pulsed correlation ToF (PC-ToF), a new mode that improves local depth resolution around a target depth with low power and modulation frequency.

Findings

Achieves 2mm depth resolution at 10MHz modulation

Operates effectively with as low as 1mW optical power

Provides localized high sensitivity for scene feature acquisition

Abstract

We introduce pulsed correlation time-of-flight (PC-ToF) sensing, a new operation mode for correlation time-of-flight range sensors that combines a sub-nanosecond laser pulse source with a rectangular demodulation at the sensor side. In contrast to previous work, our proposed measurement scheme attempts not to optimize depth accuracy over the full measurement: With PC-ToF we trade the global sensitivity of a standard C-ToF setup for measurements with strongly localized high sensitivity -- we greatly enhance the depth resolution for the acquisition of scene features around a desired depth of interest. Using real-world experiments, we show that our technique is capable of achieving depth resolutions down to 2mm using a modulation frequency as low as 10MHz and an optical power as low as 1mW. This makes PC-ToF especially viable for low-power applications.