| 摘要 |
<p>A fast median filter (22) is disclosed for filtering high frequency noise from signals, such as, signals (10, 14) from a radio altimeter. The filter (22) continuously provides the median of a predetermined number of points of the signal, which are received in an array, by successively comparing (60) each data point in the array with each other data point in the array. A counter is either incremented (62) or decremented (64) depending on the result of each comparison. If the counter reaches a predetermined value at the end of the sequence of comparisons, the median is determined. A pointer (30) keeps track of the oldest data point in the array (42). After the median is determined, a new data point is received into the array and written over the oldest data point (34). The median of the array is determined each time the array is updated with a new data point (32). When the pointer reaches the last position in the array, the pointer is reset to the first position and is subsequently incremented in the same manner (40).</p> |
