GPS World

Tag: Raspberry Pi

  • Inexpensive sensor created to monitor Rhine river levels

    Inexpensive sensor created to monitor Rhine river levels

    A team of researchers has developed a low-cost sensor that can detect the changes in river height to provide wide-area flood warnings.

    The Raspberry Pi Reflector (RPR) was designed by a team of scientists from the University of Bonn, the Federal University of Rio Grande do Sul, and the University of Colorado.

    The solar-powered RPR is much less expensive (about US$150) than scientific-grade or geodetic GNSS instruments — the cost of which is “a limiting factor for their prompt and more widespread deployment as a dedicated environmental sensor,” the team writes in their paper.

    The Raspberry Pi Reflector (RPR) prototype includes a low-cost and low-maintenance single-frequency GPS module (an Adafruit GPS FeatherWing receiver) and an unspecified GPS antenna connected to an inexpensive Raspberry Pi microcomputer. One such unit has been successfully operating since March 2020 in Wesel, Germany, next to the Rhine river.

    Photo:
    The RPR hardware array: (a) Raspberry Pi 4 Model B (b) Adafruit Feather Adalogger microcontroller (c) Adafruit GPS FeatherWing receiver (d) GPS external antenna (e) Configuration of RPR prototype setup. (Image: Karegar, et al)

    The unit on the Rhine provides sub-daily and daily water levels retrieved using spectral analysis of reflection data, or GNSS-reflectometry. The river level measurements from the RPR are compared with a co-located river gauge.

    By changing the orientation of the antenna from upright to sideways facing the river, which was done in August 2021, the root-mean-square error (RMSE) was lowered to from 7.6 cm to 3 cm (sub-daily) and 6 cm to 1.5 cm (daily), the team said.

    “While satellite radar altimetry techniques have been utilized to monitor water levels with global coverage, their measurements are associated with moderate uncertainties and temporal resolution,” the team states. “Therefore, such low-cost and high-precision instruments can be paired with satellite data for calibrating, validating and modeling purposes.”

    Information about the RPR is available on GitHub.

  • Septentrio open-source software and hardware aimed at autonomous applications

    Septentrio open-source software and hardware aimed at autonomous applications

    Septentrio, a leader in high-precision GNSS positioning solutions, is offering two open-source resources for its GPS/GNSS module receivers.

    • The first, ROSaic, is a Robot Operating System (ROS) driver for the mosaic-X5 module as well as other Septentrio GNSS receivers.
    • The second project, mosaicHAT, is an open source hardware reference design combining mosaic-X5 with a Raspberry Pi single-board computer.

    Both projects facilitate integration of centimeter-level reliable positioning into robotic and other machine automation applications.

    Photo: Septentrio
    Photo: Septentrio

    ROSaic driver operates on ROS, a widely used programming environment within the industry as well as academics, commonly used for integrating robot technology and developing advanced robotics and autonomous systems. ROS allows data from numerous sensors to be combined allowing high levels of autonomy.

    The mosaicHAT project facilitates accurate and reliable GNSS positioning for robotics and automation on a hardware level. Numerous engineers today use Raspberry Pi for prototyping and initial integrations. The mosaicHAT board is an easy way for integrators to get started with Septentrio’s mosaic-X5 GNSS module.

    By plugging mosaicHAT into a compatible Raspberry Pi, users have access to high-accuracy positioning with a high update rate, ideal for machine navigation and control, the company said. The small 56×65 mm board exposes basic interfaces such as USB, serial and general-purpose communication pins. The reference design, footprint and documentation are available for easy board printing or further customization.

    “We are excited about both the ROSaic driver and the mosaicHAT being part of the GitHub community and we highly appreciate the initial authors work as well as the future contributors,” said Gustavo Lopez, market access manager at Septentrio. “Both projects are available as open source, thus empowering the community to easily fit autonomous or robotic systems with highly accurate and reliable GNSS positioning technology.”

    The ROSaic driver is available on the ROS wiki page and on the Septentrio GitHub repository while the mosaicHAT can be found here.

    ROS is a trademark of Open Robotics. Raspberry Pi is a trademark of the Raspberry Pi organization.