The Geometer is very simple to use. The observer sights on the target using the red dot sight, and presses the button. When the button is pressed, geometer pitch, yaw, roll and computer time are recorded to a device-specific text file. The text file is automatically saved after every update to avoid data loss in case of computer malfunction.
The measured angles and measurement time, along with platform height and velocity, are then used to estimate the exact location of the target relative to the user at the time of the measurement.
The Geometer will typically be used in spatially constricted circumstances such as in the bubble window of a survey plane. This puts demands on the physical dimensions of the device. In addition the Geometer will be used from fast-moving platforms where the observer will only have a few seconds to record a sighting. It must therefore be very quick and easy to sight a target and record data. It will also be used in a wide range of lighting and glare conditions, putting demands on the type and configuration of the sight.