Range is the distance from one object to another. In fire control, it is generally assumed a given range is that between the gun and the target. Subtle yet significant distinctions sometimes require more specific terminology or a careful reading of the context:
- Clock Range (also sometimes called "plot range" or "current range", etc) expresses the range between observer and the object in question
- Gun Range, that range suitable for setting on a Gun Sight, may differ from plot range for a number of reasons.
- A rangefinder can provide an estimate of the current range to an object
- A gun sight can be set to a given range and align the sighting telescope to the proper angle for firing
- Almost any other calculating fire control instrument reflects a consideration of a range in its function
Units of Measurement
The Royal Navy and US Navy expressed range in yards. Although some instruments may treat range continuously, it is often communicated in quanta of 25 yards, and spotting corrections for range are usually quantized to 100 yard intervals.
The German Navy expressed range in hectometres (a hectometre is 100 metres).