An intravascular system comprising: a catheter (102; 202; 502; 802; 1002) including a proximal end, a distal end, a sensor (108; 208; 808) located at the distal end, and a cable (268; 968; 1068) extending from the proximal end of the catheter to the distal end of the catheter and operatively connected to the sensor (108; 208; 808) at the distal end, the sensor configured to provide an intravascular signal representative of one or more intravascular properties of a patient; at least one friction wheel (970, 972; 1070, 1072) operatively engaging the cable (268; 968; 1068) of the catheter (102; 202; 502; 802; 1002) such that distal and proximal motion of the cable causes rotation of the at least one friction wheel; a position sensor (822; 922; 1022) including a reference element (824; 924; 1024) and a moveable element comprising a plurality of detectable elements, wherein each of the plurality of detectable elements have different magnetic properties, such as magnetization strength or direction, and are spaced apart in certain ways and/or arranged in certain orders such that these elements are distinguishable from one another by an output of the reference element, the position sensor configured to generate a position signal based on the output of the reference element, the plurality of detectable elements (927; 1027) configured to move relative to the reference element in response to rotation of the at least one friction wheel (970, 972; 1070, 1072); and an intravascular processing engine in communication with the sensor (108; 208; 808) of the catheter (102; 202; 502; 802; 1002) and the position sensor (822; 922; 1022) and configured to receive the intravascular signal from the sensor of the catheter and the position signal from the position sensor. a catheter (102; 202; 502; 802; 1002) including a proximal end, a distal end, a sensor (108; 208; 808) located at the distal end, and a cable (268; 968; 1068) extending from the proximal end of the catheter to the distal end of the catheter and operatively connected to the sensor (108; 208; 808) at the distal end, the sensor configured to provide an intravascular signal representative of one or more intravascular properties of a patient; at least one friction wheel (970, 972; 1070, 1072) operatively engaging the cable (268; 968; 1068) of the catheter (102; 202; 502; 802; 1002) such that distal and proximal motion of the cable causes rotation of the at least one friction wheel; a position sensor (822; 922; 1022) including a reference element (824; 924; 1024) and a moveable element comprising a plurality of detectable elements, wherein each of the plurality of detectable elements have different magnetic properties, such as magnetization strength or direction, and are spaced apart in certain ways and/or arranged in certain orders such that these elements are distinguishable from one another by an output of the reference element, the position sensor configured to generate a position signal based on the output of the reference element, the plurality of detectable elements (927; 1027) configured to move relative to the reference element in response to rotation of the at least one friction wheel (970, 972; 1070, 1072); and an intravascular processing engine in communication with the sensor (108; 208; 808) of the catheter (102; 202; 502; 802; 1002) and the position sensor (822; 922; 1022) and configured to receive the intravascular signal from the sensor of the catheter and the position signal from the position sensor.