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Visitor II
April 1, 2021
Question

I am looking for a GNSS module that is able to get a fix indoors.

  • April 1, 2021
  • 4 replies
  • 1322 views

Are there any ST offerings that are capable in that scenario?

    This topic has been closed for replies.

    4 replies

    Graduate II
    April 1, 2021

    Signals are too weak to receive within most structures​

    ST Employee
    April 1, 2021

    Hi @EKowa.1​ ,

    I agree with Tesla, the indoor navigation with a GNSS module is a bit tricky for many reason.

    You could however check existing solution like the Teseo-LIV3F, if they can be suitable for your purpose.

    A better solution could be implementing dead reckoning algorithm with an IMU: the Teseo-VIC3DA is an automotive GNSS dead reckoning module with 6-axis IMU; this product is however in the pre-release phase now.

    You can browse Teseo product selector page for more info.

    -Eleon

    Explorer
    April 1, 2021

    I came across some modules claiming such capabilities, and got the expected result when trying one.

    There is no rigid definition of "indoors", and the associated signal attenuation.

    I suppose a glass or plastic foil greenhouse counts as "indoors", too.

    EKowa.1Author
    Visitor II
    April 1, 2021

    There must be some better than others, or some implementations better than others. I have a bicycle gps that happily gets a fix inside my house, while my older automotive gps gets nothing, not even at the windows. Both of these devices were made by the same manufacturer, but many years apart.

    My smart phone, made a couple of years ago also gets a fix inside, and my house has a steel frame, steel roof and is wrapped in metal foil sisalation. The gps signal must be seriously degraded. The phone signal certainly is. My old phone was quite useless inside.

    Graduate II
    April 1, 2021

    Well they've travelled 25,000 KM. In the normal GPS model the kinetic portion does the building penetration.

    Signals also tend to get masked in certain directions, and bounce off things, make accuracy problematic. So even with some high-gain antenna, amp and processing the overall performance is relatively lackluster.

    You need at least 32 dBHz CNo to demodulate navigation data on GPS.

    Cell phones often provide AGPS data so you can get below those thresholds, and also do their own localization.

    In-building people usually use other methods to determine rooms/floors, think emergency / fire fighter type applications. Either via beacons, WiFi AP, and radio heat-mapping.

    Dead-reckoning needs to come from where you already have location fix, and the quality drops/deteriorates the longer you're without. Cars have wheel-ticks, and constrained motion, people less so.