The purpose of an electronic Compass and Vertical Angle Measurement (CVAM) sensor is to measure the attitude/orientation (i.e., azimuth, elevation, and cant; in terms of true North and local vertical) of the object to which it is attached. This measurement of orientation enables the addition of valuable functionality to the soldier system. Currently the Force XXI Land Warrior (FXXI LW) program is funding the development of a CVAM and its integration onto the Integrated Helmet Assembly Subassembly (IHAS) of the Land Warrior system. The primary intent of the FXXI LW effort is to produce a Head Orientation Sensor (HOS) that, when combined with data from a corresponding Weapon Orientation Sensor, enables a new function for the Land Warrior system known as Rapid Target Acquisition (RTA). The RTA functionality is only one of a set of soldier functions enabled by the CVAM. It is the objective of this paper to describe the CVAM/HOS and its various applications within the soldier systems. The introduction of the paper provides the history and background of the CVAM and its operation. The body of the paper is first focused on an overview of CVAM operation and the means by which it is to be integrated into various systems (to include helmets, advanced weapon sights, chemical sensing platforms, etc.). This will include the unique needs of the sensor such as calibration and parameter adjustment, and its key features that make it excel in its operational environment. The remainder of the paper focuses on the application of the CVAM to soldier systems; the benefits that CVAM offers to existing functions and the new functionality it enables. Various soldier functions and capabilities (new and pre-existing) are described. The paper concludes with a description of the status of the effort. This includes the developmental status of the CVAM/HOS, the validation of its design, and its integration into the IHAS and other weapon and sensing platforms.