Hi Dirk: On Sat, 2019-01-12 at 18:40 +0000, Dirk Gorissen wrote: > Better late than never, but massive thanks to Andy, Marcus and the > GnuRadio community: > > https://dirkgorissen.com/2019/01/06/wheres-pinoh-tracking-orangutans- > with-drones-and-gnu-radio/
You're welcome. It was our pleasure to help. I was wondering when the report would come out. I had periodically checked your Twitter for the few months following March 2018, but never saw anything. I'm sure the data analysis is fascinating, even though the collection was degraded by the sub-optimal antenna. I've been in a similar situation: collect data with sub-optimal system, get tantalizing bits of good data along with lots of noisy data, fix system and wait for opportunity to collect more data. Waiting for the time window to get more data with the fixed system is frustrating. :P In your report you mention: 1. "Some implants seemed to transmit much longer and stronger than the 10ms pulse they should be transmitting." That lengthened pulse will widen your time domain correlation "peaks". The stronger pulse will muck with your thresholds, if the thresholds aren't adaptive. Or maybe you're using a CFAR detector? (As I write this, I'm musing how similar this is to RADAR or IFF: pulse compression followed by a CFAR filter/detector.) 2. "The pulse would also be mirrored in the spectrum at times [...]" An impairment common to almost all SDR hardware is I/Q imbalance (along with DC offset). I/Q imbalance will result in the spectrum having a weaker image of the signal spectrum reflected about 0 Hz. If the SDR manufacturer hasn't calibrated most of the imbalance away for you using harware chip functions, you have to get rid of I/Q imbalance and DC offset using software. Some more reading on the topic, if it matters to you: https://www.analog.com/media/en/technical-documentation/application-notes/AN-1039.pdf https://www.faculty.ece.vt.edu/swe/argus/iqbal.pdf https://cgit.osmocom.org/gr-iqbal/ Also, unless "Alan Walls" speaks up, I think you typo'ed my name at the end of your write-up. :) Anyway, great work. Being the Principal Investigator and doing all the hardware, software, analysis, and field data collection legwork is a big job for one person. Regards, Andy _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio