Indoor navigation

GPS outdoors only works well when there is a clear open space to the sky. Is it possible then to get help with indoor navigation? Well perhaps eventually there will be, using the carrier pigeon method.

Story by: Morten Tollefsen - 17.07.2012

There is still much work that needs to be done to provide pedestrians with a good navigational aid outdoors. MediaLT is looking into this in the project "Improved GPS for the visually impaired." In this project we also consider the various support technologies that improve accuracy and thus provide more appropriate instructions. Indoor navigation is not the main topic of this project, but it is certainly necessary for visually impaired to be able to find their way around in unfamiliar places without help. Many routes include railway stations, indoor subways, locations of shops in a shopping centre, etc.

In this article you will find out a little about what is happening with indoor navigation.

New chips

New chips are constantly evolving with enhanced positioning techniques. One of the latest is Broadcom (BCM4752). This chip supports satellite systems, GPS, GLONASS and QZSS. This will ensure more accurate navigation outdoors. Positioning using WLAN is widespread, and BCM4752 also supports the up and coming 802.11ac technology. Data from accelerometer, gyroscope, magnetometer and altimeter are utilized to calculate the positioning where satellites are unavailable.

Indoor mapping services

You may have heard that Google maps also include indoor maps? As far as I know they are only available for large stores and shopping centers. Although I have no experience of how accurate they are (they are not available in Norway), I assume the accuracy is not good enough to find your way around as a severely visually impaired. Business photos (a Google service) may be of help for some, as a preparation beforehand. Business photos is not currently available in Norway, and of course it is not really intended as a navigational aid.

NTNU (Norwegian University of Science and Technology) has outdoor GPS navigation combined with WLAN indoor navigation. It's called Campus Guide, and the precision indoors is at best 5-10 m (rather like the precision you get with GPS outside). This is possible because NTNU has many wireless routers (ca. 1800). I have downloaded this app on the iPhone, but it does not seem possible to use it for navigation for the blind.

Carrier Pigeons are smart

People have used carrier pigeons for thousands of years. It was also a carrier pigeon that brought the olive branch to Noah in the ark. I do not think we know for sure how pigeons navigate so accurately over large distances, but the magnetic field is probably important.

Researchers at the University of Oulu (in Finland) have started the company IndoorAtlas. The amount of steel in a building changes the earth's magnetic field making it possible to calculate points down to an accuracy of 0.1 to 2 metres. Buildings must be "mapped" before the system will work, and changes to the building will necessitate new surveys. IndoorAtlas has released tools for mapping and programming. Many smart phones have the sensor that is needed to use the technology, so now we just have to hope that many are surveying their buildings! I doubt that this is suitable for all environments (for example train stations), but to me it does sound really exciting.

News archive