| Description: For some observations, geometric parameters are given as instantaneous values at a specific time. Another set of instantaneous parameters are the parameters which give the minimum and maximum values in the product. In some cases, these range values are all calculated for the same time. If the label includes single valued geometric parameters or min/max range parameters determined for a specific time, geometry_reference_time_utc gives the time for which these values were calculated and must be given in the label. For some instruments, particularly those with relatively large exposure durations, (e.g., push broom cameras, many imaging spectrometers), many geometric quantities are given as ranges. If those range parameters are associated with the beginning and end of the observation (start_parameter/stop_parameter), geometry_start_time_utc/stop_time must be given. Comments within the label should be used to ensure the parameter vs. time association is unambiguous. |