A body-worn tracking device (BWTD) comprising: a global navigation satellite system (GNSS) device; at least one motion sensor; at least one processor; and at least one memory device comprising instructions that, when executed by the at least one processor, cause the at least one processor to: responsive to determining that a current location of the BWTD cannot be determined using the GNSS device, determine, based on data generated by the at least one motion sensor, a net distance between the last known location of the BWTD and the current location of the BWTD; determine, based on the net distance, whether the BWTD is within a bounded area that includes the last known location; and responsive to determining that BWTD is not within the bounded area, output an indication that the BWTD is not within the bounded area; wherein the at least one motion sensor comprises: an accelerometer; and a gyroscope; wherein the instructions that cause at least one processor to determine the net distance cause the at least one processor to determine the net distance based on data generated by the accelerometer and data generated by the gyroscope, wherein the instructions that cause the at least one processor to determine the net distance cause the at least one processor to: detect, based on the data generated by the accelerometer, a plurality of steps; determine an estimated distance traveled during each step of the plurality of steps; determine, based on the data generated by the gyroscope, a direction of travel of each step of the plurality of steps; determine, based on the estimated distance traveled during each step and the direction of travel of each step, the net distance between the last known location of the BWTD and the current location of the BWTD; wherein the BWTD further comprises a magnetometer, and wherein the at least one processor is further configured to: calibrate, based on data generated by the magnetometer, the gyroscope. a global navigation satellite system (GNSS) device; at least one motion sensor; at least one processor; and at least one memory device comprising instructions that, when executed by the at least one processor, cause the at least one processor to: responsive to determining that a current location of the BWTD cannot be determined using the GNSS device, determine, based on data generated by the at least one motion sensor, a net distance between the last known location of the BWTD and the current location of the BWTD; determine, based on the net distance, whether the BWTD is within a bounded area that includes the last known location; and responsive to determining that BWTD is not within the bounded area, responsive to determining that a current location of the BWTD cannot be determined using the GNSS device, determine, based on data generated by the at least one motion sensor, a net distance between the last known location of the BWTD and the current location of the BWTD; determine, based on the net distance, whether the BWTD is within a bounded area that includes the last known location; and responsive to determining that BWTD is not within the bounded area, output an indication that the BWTD is not within the bounded area; an accelerometer; and a gyroscope; wherein the instructions that cause at least one processor to determine the net distance cause the at least one processor to determine the net distance based on data generated by the accelerometer and data generated by the gyroscope, wherein the instructions that cause the at least one processor to determine the net distance cause the at least one processor to: detect, based on the data generated by the accelerometer, a plurality of steps; determine an estimated distance traveled during each step of the plurality of steps; detect, based on the data generated by the accelerometer, a plurality of steps; determine an estimated distance traveled during each step of the plurality of steps; determine, based on the data generated by the gyroscope, a direction of travel of each step of the plurality of steps; determine, based on the estimated distance traveled during each step and the direction of travel of each step, the net distance between the last known location of the BWTD and the current location of the BWTD; wherein the BWTD further comprises a magnetometer, and wherein the at least one processor is further configured to: calibrate, based on data generated by the magnetometer, the gyroscope.