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    <p>You get position by integrating the linear acceleration twice but <strong>the error is horrible. It is useless in practice.</strong></p> <p>Here is <a href="http://www.youtube.com/watch?v=C7JQ7Rpwn2k" rel="noreferrer">an explanation why (Google Tech Talk)</a> at <a href="http://youtu.be/C7JQ7Rpwn2k?t=23m21s" rel="noreferrer">23:20</a>. I highly recommend this video.</p> <p>It is not the accelerometer noise that causes the problem but the <a href="http://www.cl.cam.ac.uk//techreports/UCAM-CL-TR-696.pdf" rel="noreferrer">gyro white noise</a>, see subsection 6.2.3 Propagation of Errors. (By the way, you will need the gyroscopes too.)</p> <p>As for indoor positioning, I have found these useful: </p> <p><a href="https://www.researchgate.net/publication/224605820_RSSI-Based_Indoor_Localization_and_Tracking_Using_Sigma-Point_Kalman_Smoothers" rel="noreferrer">RSSI-Based Indoor Localization and Tracking Using Sigma-Point Kalman Smoothers</a></p> <p><a href="http://www.intersense.com/uploads/documents/Pedestrian_Tracking_with_Shoe-Mounted_Inertial_Sensors.pdf" rel="noreferrer">Pedestrian Tracking with Shoe-Mounted Inertial Sensors</a></p> <p><a href="http://www.analog.com/static/imported-files/application_notes/47076299220991AN_900.pdf" rel="noreferrer">Enhancing the Performance of Pedometers Using a Single Accelerometer</a></p> <p>I have no idea how these methods would perform in real-life applications or how to turn them into a nice Android app.</p> <p>A similar question is <a href="https://stackoverflow.com/questions/6645126/distance-moved-by-accelerometer/6648664#6648664">this</a>.</p> <p><strong>UPDATE:</strong></p> <p>Apparently there is a newer version than the above Oliver J. Woodman, "An introduction to inertial navigation", his PhD thesis:</p> <p><a href="http://www.cl.cam.ac.uk/research/dtg/www/people/ojw28" rel="noreferrer">Pedestrian Localisation for Indoor Environments</a></p>
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    1. POAndroid accelerometer accuracy (Inertial navigation)
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    1. POAndroid accelerometer accuracy (Inertial navigation)
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    1. COWell, good luck! :)
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    2. COI realise this is a long time ago, but I've got a follow-up question. The camera in Android JB has a 'panorama' feature, which lets you take a panoramic picture by moving the phone, either rotating it *or* moving it linearly along one axis. To do this it has to track the position of the phone relatively accurately - at least better than the 20cm/s error mentioned in the video this answer links. How does it do it? Does it have some way of improving the quality of inertial tracking? Or does it use clever image processing to do it using only the camera?
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    3. CO@Tom I believe the latter, the phone concatenates together the pictures purely by image processing algorithms. What makes you think that the phone has to track its position to produce a panorama picture? It was possible to do it with ordinary cameras back in the 90's and clearly, we did not have accelerometers in the cameras back then :) Of course, the pictures were concatenated on an ordinary PCs. But you don't need the position for this, image processing algorithms are sufficient. Hope this helps.
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