That's an older form of ranging. It's easier to do than pulse ranging, but you have to outshine ambient light at the color being used full time. The Swiss Ranger [1] is a good example of such a system. It's indoor only and short range. With a pulse system, you only have to outshine ambient light for a nanosecond, which is quite possible in sunlight.
I've been expecting good, cheap non-scanning laser distance imagers for a decade. In 2003, I went down to Advanced Scientific Concepts in Santa Barbara and saw the first prototype, as a collection of parts on an optical bench. Today ASC makes good units [2], but they cost about $100K. DoD and Space-X buy them. There's one on the Dragon spacecraft, for docking. That technology isn't inherently expensive, but requires custom semiconductors produced with non-standard processes such as InGaAs. Those cost too much in small volumes. There's been progress in coming up with designs that can be made in standard CMOS fabs.[3] When that hits production, laser rangefinders will cost like CMOS cameras.
I've been expecting good, cheap non-scanning laser distance imagers for a decade. In 2003, I went down to Advanced Scientific Concepts in Santa Barbara and saw the first prototype, as a collection of parts on an optical bench. Today ASC makes good units [2], but they cost about $100K. DoD and Space-X buy them. There's one on the Dragon spacecraft, for docking. That technology isn't inherently expensive, but requires custom semiconductors produced with non-standard processes such as InGaAs. Those cost too much in small volumes. There's been progress in coming up with designs that can be made in standard CMOS fabs.[3] When that hits production, laser rangefinders will cost like CMOS cameras.
[1] http://www.adept.net.au/cameras/Mesa/SR4000.shtml [2] http://www.advancedscientificconcepts.com/products/overview.... [3] https://books.google.com/books?id=Op6NCwAAQBAJ&lpg=PA64