Accurate Indoor Localization with Zero Start-up Cost


This invention has commercial application for industries that require easily deployable tracking or localizing technology for use in complex indoor environments. For example, accurate indoor localization on handheld devices can help companies more readily track tagged and untagged assets in warehouses or department stores.

Problems Addressed

Existing approaches for indoor localization require either deployment of new infrastructure or extensive fingerprinting of a surrounding environment to learn spatial distribution of signal strength. Synthetic Aperture Radar (SAR), a technique that collects signal snapshots along a trajectory through transmission of successive radio wave pulses, seems to offer a way for mobile devices to mimic an antenna array and perform indoor localization. However, SAR in its existing form is unsuitable for mobile devices due to the controlled speed and trajectory required for accuracy. The inventors demonstrate a novel formulation of SAR that enables mobile devices to accurately perform RF localization and object geotagging in complex indoor settings.  


This patented technology enables handheld devices to serve as indoor geo-location systems without requiring special infrastructure or environmental fingerprinting. To achieve this, the invention relies on a new formulation of SAR that allows mobile devices to emulate large antenna arrays and that achieves significantly improved accuracy in indoor RF (radio frequency) localization. This formulation of SAR is translation resistant, which means users can twist their mobile device along unknown paths to perform SAR using today's off-the-shelf Wi-Fi cards and motion sensors.

In addition to localizing RF devices, this patented invention combines RF localization with stereo-vision algorithms to localize common objects with no RF source attached to them. This approach for object geotagging using a device's existing camera has important implications for wide-scale adoption of accurate indoor localization techniques using commercially available mobile devices.


  • Ability to perform Synthetic Aperture Radar (SAR) on handheld devices
  • Works on handheld mobile devices already in the pockets of people