How is this possible? The key point here is that the satellite visibility number is a CALCULATED value, not the result of a real time activity being performed by the receiver. A receiver containing a valid almanac, time, and position can CALCULATE which satellites SHOULD BE visible (above the horizon) and will report these as VISIBLE. If a newly activated receiver has determined it’s position but has yet to download an almanac, it will continue to report zero satellites visible until the almanac has been downloaded (approx. 15 minutes after the first satellite is acquired).