GPS logs on APM

Guys, I'm flying a blimp indoors and connected APM2.0 to the receiver via Y cables to log radio inputs and sensor outputs. When I look at the log files in dataflash I can see that during the flight all GPS related data are zero since there is no GPS indoors as expected. However 'GPS time' value is zero for some time then it starts to increase. If there is no GPS how can this happen? First I assumed maybe it only can see one satellite so it can get the time but not the remaining parameters, however when I look at 'GPS sats' parameter which logs the number of locked satellites on log file, it is always zero.  Also I have another concern regarding waypoint navigation. Without GPS can I assign waypoints on a custom made map? 

2012-12-24 21-23 2.log

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  • You can use a precise (+-2cm) Indoor "GPS":

    Here is a couple of demos:

  • Hi!

    While connecting the MTK GPS directly to pc (FTDI Adapter) and watching MiniGPS i observed the same: No Fix No lat No lon but a timestamp counting. Maybe it is some signal of one Sat - i don't know but it is normal and no use for navigation of any kind. For indoor navigation you will have to establish your own "kind of- GPS- thing" with special senders etc... Or use and integrate advanced sensor set (Sonar/IR/Radar/Flowsensor/ Optical recognition) in combination. I think this subject to current research.


    Kraut Rob

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Shivchand Jaysaval liked Shivchand Jaysaval's profile
Aug 25