A method and system for generating and maintaining a database comprising a
location-sensitive timetable. At multiple locations, a device (e.g., an
integrated position and direction system) listens for broadcast signals
from broadcasting devices (e.g., Global Positioning System satellites).
For each location, the device records the time and date and the number of
satellites from which a signal is received. The device can also record the
identities of satellites that can and cannot be picked up. The information
recorded by the device can be used to automatically generate a timetable
showing the dates and times of day for each location that are and are not
satisfactory for doing data maintenance, based on the number of satellites
available for viewing. The recorded information can also be used to
automatically predict future dates and times for each location that will
or will not be satisfactory for data maintenance. Each visit to a location
accumulates additional information regarding when satellites will and will
not be available for viewing. In this manner, a timetable is automatically
generated and updated. The timetable can be automatically factored into
mission planning for data maintenance by creating a schedule for visiting
each location when satellite viewing will be satisfactory.