4.1 Target Number [Target_Number]

Each target must have a unique target number (base 10 from 1 to 999) and are usually assigned by the APT software. Target numbers must be positive, monotonically increasing integers. You should define a different target whenever a different target position or timing description is required. For example, separate targets should be defined if you plan to take spectra of several different surface features on a planet, or if you plan to observe the same feature with different timing constraints.