GPS-enabled robots are being used in California's Sacramento-San Joaquin river system to monitor volume, quality, speed, & flow direction of fresh and salt water through the Sacramento Delta. Some members of this floating data collection network even have propellors for maneuvering, and all are sending tweets to @fsnandroid61. The river system being monitored supplies about two-thirds of California's fresh water. Read more or view a video about this innovative application of GNSS technology in this GPS World article.
Rothe & Associates, PLLC 