Abstract: An alignment device for measuring orientation of a drill rig having a chuck is disclosed. The device can comprise a tubular housing having a cylindrical outer surface and defining an inner bore. The tubular housing can be configured to be receivable into the chuck of the drill rig. A gyroscopic orientation sensor can be disposed within the tubular housing. The gyroscopic orientation sensor can be configured to provide a signal indicative of an orientation of the alignment device. A wireless transmitter can be in communication with the gyroscopic orientation sensor. The wireless transmitter can be configured to transmit a wireless output indicative of the orientation of the alignment device.

Abstract: A control unit can comprise a housing and circuitry disposed within the housing. The circuitry can comprise a communications module, a memory, and a processor in communication with the memory and the communications module. A power source can be disposed within the housing. An input port that is configured to mate with a complementary output of a sensor unit that is external to the housing. The input port can be in communication with the circuitry. The input port can be configured to interface with the sensor unit.

Abstract: Disclosed herein, in one aspect, is a system for determining depth within a borehole. The system can comprise a downhole device comprising at least one inertial sensor, at least one processor, and a memory in communication with the at least one processor. The memory can comprise instructions thereon that, when executed, cause the processor to: receive data from the at least one inertial sensor and store the data from the at least one inertial sensor in the memory with respective correlated time values. The system can further comprise a drill rig comprising at least one depth measurement device. The at least one depth measurement device can comprises a drill string position sensor that is configured to produce a measurement indicative of a length of a portion of a drill string removed from a borehole or a wireline sensor that is configured to determine a length of deployed wireline cable.