Re: [time-nuts] GNSS beam forming

2018-08-31 Thread Gregory Maxwell
On Fri, Aug 31, 2018 at 5:16 PM jimlux wrote: > AJ is a slightly different problem than straight up beamforming > > You need N+1 receivers to suppress N point source jammers - it's more of > an adaptive canceller than a beamformer. One nice property of AJ though is that the nulls it forms can be

Re: [time-nuts] GNSS beam forming

2018-08-31 Thread jimlux
On 8/31/18 9:38 AM, Gregory Maxwell wrote: On Fri, Aug 31, 2018 at 2:56 PM Attila Kinali wrote: "Just DSP work" is a tad bit more than you think. You are dealing with sevaral 1Msps of data, even for a simple L1 C/A receiver. If you are going multi-band-multi-GNSS you are usually in the 50MHz BW

Re: [time-nuts] GNSS beam forming (was: NIST)

2018-08-31 Thread Gregory Maxwell
On Fri, Aug 31, 2018 at 2:56 PM Attila Kinali wrote: > "Just DSP work" is a tad bit more than you think. You are dealing > with sevaral 1Msps of data, even for a simple L1 C/A receiver. > If you are going multi-band-multi-GNSS you are usually in the 50MHz BW > at L1 and 80MHz BW at L2/L5 range, wh

Re: [time-nuts] GNSS beam forming (was: NIST)

2018-08-31 Thread Scott McGrath
I/We track down things that jam weather radars. Mostly WiFi access points misconfigured. Which share many of the characteristics of GPS jammers 1 - small low powered 2 - one can ruin a pilots entire day 3 - distributed 4 - can literally be anywhere Stuff like this is why FCC blocked anyone

[time-nuts] GNSS beam forming (was: NIST)

2018-08-31 Thread Attila Kinali
On Thu, 30 Aug 2018 23:05:48 + Gregory Maxwell wrote: > Seeing some open source software implementing beam-forming was one of > the things I hoped to see result from the open hardware multi-band > GNSS receivers like the GNSS firehose project ( > http://pmonta.com/blog/2017/05/05/gnss-fireho