Some words about terminology.
I made a comment about how MEMS might help power onboard GPS. My comment comes from an engineer's view of the overall system. For me "GPS" is narrowly interpreted as the US satellite system, and this excludes MEMS or high-end sensors as well as other satellite navigation systems such as GLONASS, Galileo or the Chinese navigation system.
Since the Russians decided to improve and properly maintain their GLONASS satellites, these systems have been recently incorporated with existing GPS receives to form what are now called GNSS receivers. This incorporation of different satellite systems gives rise to a more generic "Global Navigation Satellite System."
These GNSS technologies do not include maps or databases of addresses and phone numbers. The handheld or in-dash systems available in the consumer markets are more properly termed "navigation units" or "sat-nav units," but it is unavoidable that some will continue to call these "GPS units" or simply "GPS," as in "I had to use my GPS to get here."
Several years ago I saw a video indicating that Broadcom were planning on integrating GPS and MEMS sensors, and this idea ultimately led me to invest in InvenSense earlier this year. Broadcom already have a GPS-GLONASS product in Samsung's Galaxy S4, and some would prefer to call this a GNSS receiver, but for a press release, I think this was called a GPS product to avoid confusing the reader.
Broadcom's senior program manager, Steve Malkos, who described an innovative sensor fusion algorithm for determining location information for vehicles by combining the outputs from GPS with the dead-reckoning capabilities of accelerometer, gyroscope, magnetometer, and altimeter.
The citation above is from brokenSt0nes' link. This type of integration can be considered a "integrated navigation system" or a hybrid system, or something along those lines. However, from a narrow definition, these systems have moved well beyond simple GPS.
Another article:
blog.broadcom.com
How Broadcom’s HULA Helps GPS Work Better in Crowded Cities
snip
These sensors, which engineers call Micro-Electro-Mechanical Systems (MEMS), have been a hot topic of late. Last week, Malkos spoke at a conference devoted to exploring MEMS-based innovations and a blog post in the EETimes quoted him as saying, “Broadcom has been working on HULA since 2006. Now it provides superior accuracy even in the canyons of cities where buildings are often in the way of GPS signals.”
Although the conference discussion gets pretty techie, Malkos described how MEMS sensors on the smartphone – including accelerometers, gyroscopes, magnetometers and altimeters – can help compensate for blocked GPS signals or stray magnetic fields, resulting in more accurate location information.
All of the inputs from these sensors are synthesized using Broadcom’s Positioning Engine (HULA). This engine cuts the positioning errors back to a more acceptable two-to-five meters and greatly reduces “position jumps” in the GPS as users move around a city. |
