A global navigation satellite system (GNSS) based control system is provided for positioning a working component relative to a work surface, such as an agricultural spray boom over a crop field. Inertial measurement unit (IMU) sensors, such as accelerometers and gyroscopes, are mounted on the working component and provide positioning signals to a control processor. A method of positioning a working component relative to a work surface using GNSS-based positioning signals is also disclosed. Further disclosed is a work order management system and method, which can be configured for controlling the operation of multiple vehicles, such as agricultural sprayers each equipped with GNSS-based spray boom height control subsystems. The sprayers can be remotely located from each other on multiple crop fields, and can utilize GNSS-based, field-specific terrain models for controlling their spraying operations.
