Hi All, Related to my query re real flight playback, I thought I should start at the beginning. I found this mention here on the Avsim Flightgear forum re playback.
http://forums.avsim.net/dcboard.php?az=show_mesg&forum=198&topic_id=62&mesg_id=62&page= I am already outputting NMEA data for use by Atlas. Can I record this to disk somehow ? and if so could someone point me in the direction of information on how to replay NMEA data in Flightgear. I'm also assuming that there is currently no way of inputing pitch, roll & yaw data while playing back NMEA data ? if so would this be easy to implement ? I found this paper on the web regarding generating accurate pitch, roll, yaw, altitude, position & velocity data. http://www.cmt-gmbh.de/crossbow_gpsdmu_german_gyrotech_paper.doc I think the end product derived from the above was this: http://www.xbow.com/Products/productsdetails.aspx?sid=104 There are other papers out there from people such as creators of robot football teams all tackling similar issues. I spent the weekend digging around on the web and made some calls on Monday and it appears the component cost could be as low as �300 - �400 to make a flight logger. One particular solid state gyro is mentioned as cheap but good by everyone from amateur rocket clubs to R/C helicopter builders. However if you read the above document the real deal breaker re making a homemade flight logger is not the component cost, but the processing of the signal from the gyros into accurate attitude / position data. Someone more than at home with extended kalman filter formulae amongst other things needs to write an algorithm to process the turn rate & gps data into accurate attitude / position data. From what the paper says substantial testing would be required. This actually is rocket science ! and is way above my head ( at least 60 miles above my head ) I did think that at least with a flight logger rather than a real time device you could record raw turn rate / gps data in flight and do all the processing on your PC when you got home, not that that diminishes the complexity of maths that would need doing. >From what I've observed on this list it would be no surprise if some of the readers do understand the principles of Kalman filters. Maybe some of the information is already being shared by amateur rocketry, R/C helicopter enthusiasts etc ? It will take a while, but I am building a simple GPS logger at the moment. If anyone is interested in taking part in getting the gyro part to work I could have it built here and post it out to others for testing. Mat _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
