The entry on the second line control how frequently page4 confirms its operation by writing the current data time to the screen. Units are in seconds. In the example, messages appear on the screen after each five minutes of data. Next, the interval between observations is given. This controls how much data are used.
Units are in seconds.
For example, data may be recorded and edited using a 30 second interval, but process with page4 using a 120 second interval. The shorter interval would be have advantages for data editing, but be unnecessary for a satisfactory final solutions. Line four is the minimum observation elevation cutoff mask. Units are degrees. A gap in the data implies a discontinuity or cycle slip.