A relative positioning system enabling a user to return to a starting position or some other point on the user's path. The system may include an array of accelerometers. The output from the accelerometers may be integrated to quantify movement of the array. The various movements of the array may be reconstructed to determine a net two or three dimensional translation. The current location of the array may be compared to a reference point to derive at trajectory directing the user to the reference point The trajectory may be continuously or periodically updated. Another application may include an accelerometer array secured at various positions on a ski to monitor distortion of the ski and the skier's movements. Reconstructing the skier's movements may be accomplished by integrating the accelerometer output and transforming the integrated output into a two or three dimensional path or location.