Indoor tracking with low training and hardware costs

For indoor tracking in environments where the tags being tracked must transmit radio pings, inexpensive off-the-shelf hardware makes it practical to have approximately one or more receivers per room. Having receivers at known locations occasionally transmitting their own pings provides timely information about the path loss environment that can replace expensive training data. This works best if we are primarily interested in knowing rooms rather than exact coordinates. Tag location estimates are based on various least-squares models, with variables for tag position, ping power, and signal strength directionality. Measurement data and the resulting position estimates are combined to reduce uncertainties. Confidence scores crucial to this process are based on experience with least squares scores for the first and second most likely rooms.