Accurate indoor localization with zero start-up cost

Swarun Kumar, Stephanie Gil, Dina Katabi, Daniela Rus

Research output: Chapter in Book/Report/Conference proceedingConference contribution

284 Scopus citations


Recent years have seen the advent of new RF-localization systems that demonstrate tens of centimeters of accuracy. However, such systems require either deployment of new infrastructure, or extensive fingerprinting of the environment through training or crowdsourcing, impeding their wide-scale adoption.

We present Ubicarse, an accurate indoor localization system for commodity mobile devices, with no specialized infrastructure or fingerprinting. Ubicarse enables handheld devices to emulate large antenna arrays using a new formulation of Synthetic Aperture Radar (SAR). Past work on SAR requires measuring mechanically controlled device movement with millimeter precision, far beyond what commercial accelerometers can provide. In contrast, Ubicarse's core contribution is the ability to perform SAR on handheld devices twisted by their users along unknown paths. Ubicarse is not limited to localizing RF devices; it combines RF localization with stereo-vision algorithms to localize common objects with no RF source attached to them. We implement Ubicarse on a HP SplitX2 tablet and empirically demonstrate a median error of 39 cm in 3-D device localization and 17 cm in object geotagging in complex indoor settings.

Original languageEnglish (US)
Title of host publicationMobiCom 2014 - Proceedings of the 20th Annual
PublisherAssociation for Computing Machinery
Number of pages12
ISBN (Electronic)9781450327831
StatePublished - Sep 7 2014
Externally publishedYes
Event20th ACM Annual International Conference on Mobile Computing and Networking, MobiCom 2014 - Maui, United States
Duration: Sep 7 2014Sep 11 2014

Publication series

NameProceedings of the Annual International Conference on Mobile Computing and Networking, MOBICOM


Other20th ACM Annual International Conference on Mobile Computing and Networking, MobiCom 2014
Country/TerritoryUnited States


  • Localization
  • PHY
  • SAR
  • Wi-Fi
  • Wireless

ASJC Scopus subject areas

  • Software
  • Hardware and Architecture
  • Computer Networks and Communications


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