Technology is provided for assessing a risk of the decline of the tracking data of a main body based on one moving target of tracking. One tracking data measurement for being limited by moving target first measures the main body in the first main body of a position of one or more body segments of incremental time in a period of time based on sensing. The response of first main body is characterized based on the tracking data of the first main body. It is limited by a main body of one second tracking data of moving target measurement based on the second main body of sensing, measures a position of one or more body segments of each increment on the period. One Risk testing of the decline of second of main body is based on the first main body of the second main body and the response of response.
