||"Pitch rate" is the rate of rotation about an axis that is perpendicular to both the local vertical axis and the nominal forward motion direction of the platform. Pitch rate might not include changes to the "at rest" rotation of the platform with respect to the axis of rotation, which may change over time. The standard name platform_pitch_rate should be chosen only if the sign convention of the data is unknown. For cases where the sign convention of the pitch rate is known, a standard name of platform_pitch_rate_fore_down or platform_pitch_rate_fore_up should be chosen, as appropriate. A "platform" is a structure or vehicle that serves as a base for mounting sensors. Platforms include, but are not limited to, satellites, aeroplanes, ships, buoys, instruments, ground stations, and masts.