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POPython, numpy, scipy: How to exclude a location error from GPS coordinates? (averaging lon, lat)
 

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  1. POPython, numpy, scipy: How to exclude a location error from GPS coordinates? (averaging lon, lat)
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    <p>I use Python: </p> <p>I have 2 arrays of GPS points - lon and lat (more than 500 000 points).</p> <p>I have 1 array of date-time.</p> <pre><code>lon = numpy.array(lon) lat = numpy.array(lat) dt = numpy.array(dt) </code></pre> <p>I have a location error (GPS sensor error). For example 15 meters.</p> <pre><code>GPS_sensor_error = 0.015 </code></pre> <p><strong>I need to exclude a GPS_sensor_error from coordinates</strong> that there were no asterisks on a track. </p> <p><img src="https://i.stack.imgur.com/HZYXQ.gif" alt="enter image description here"></p> <p>(I don't draw a point with identical coordinates)</p> <p><img src="https://i.stack.imgur.com/moWKI.gif" alt="enter image description here"></p> <p><strong>How I am able to do it?</strong></p> <p>Now:</p> <ol> <li><p>I calculate distance between points. </p></li> <li><p>I find the minimum distance, if it less GPS_sensor_error, then I average lon, lat. </p></li> <li><p>repeat 1.</p></li> <li><p>repeat 2.</p></li> <li><p>repeat until all distances won't be more GPS_sensor_error</p></li> </ol> <p><strong>Update:</strong></p> <pre><code> lon = numpy.array() lat = numpy.array() flag = True while flag: lon1 = lon[:-1] lon2 = lon[1:] lat1 = lat[:-1] lat2 = lat[1:] '''distance''' x = (lon2 - lon1) y = (lat2 - lat1) d = numpy.sqrt(x * x + y * y) min = numpy.min(d) if min &lt; GPS_sensor_error: j = numpy.where(d == min)[0][0] lon[j] = (lon[j] + lon[j + 1]) / 2 lat[j] = (lat[j] + lat[j + 1]) / 2 lon = numpy.delete(lon, j + 1) lat = numpy.delete(lat, j + 1) else: flag = False </code></pre> <p>Bypass on all points works at a pure python very long... <strong>Prompt please, how to implement it using scipy, numpy?</strong></p> <p><br>Thanks</p> <p><strong>P.s. probably already there is a GPS filter in scipy, numpy?</strong></p>
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    1. COI think I understand in principle what you want to achieve, however, details are unclear from your question. Could you give a simple example (3 or 4 points), that shows what you mean by distance, what means `average lon,lat` exactly in this context?
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    2. COWhy don't you include your slow Python code? The way in which you want to conduct the averaging is not very clear from your deescription.
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    3. COI added the slow Python code to the description.
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