my experiments with an arbitrary GPS module offering a PPS discipline
showed that it is easily archievable to create a local clock (ntpd
based) with a clock precision of 1 microsecond even with cheap low-power
soc computers: I was using a Raspberry Pi.
The most interesting finding was the clock d
In case of a multilateration attempt, please consider this presentation:
https://www.youtube.com/watch?v=Km4TU17b05s
vy73
markus
dl8rds
Am Donnerstag, den 17.08.2017, 01:52 +1000 schrieb
vk4...@tech-software.net:
> Are you trying to do MultiLateration using software defined radio ?
>
>
> -
10 ms timing certainty is actually pretty hard to achieve across USB2!
But: as far as I can see, it'd be rather easy to say, tune both sticks
to DVB-T, cross-correlate to find the relative offset, tune to the
frequency of interest and work from there. That is, if the delay spread
in the cellular ch
In my experience "rf inserting" 1pps into early receiver (sampler) stages,
maybe "coding" timing with 1pps && 10Hz, all derived from gps reference.
This "affect" the signal under analysis but that can be do only
periodically... for multilateration ;-)
Victor
Il 16 ago 2017 19:45, ha scritto:
>
No.
On Thu, 2017-08-17 at 01:52 +1000, vk4...@tech-software.net wrote:
> Are you trying to do MultiLateration using software defined radio ?
>
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Say we need +-10ms accuracy in timestamps. Precision Time Protocol in LAN
should sync PC's clocks with enough accuracy.
And then using USRP-like methods - set current/start time - get first sample in
known time? Of course USB will add
undetermined delays but no external GPS required.
On Wed, 20
I have some watching to do
Can I watch them in parallel !
Sent from my iPhone
> On 17 Aug 2017, at 2:03 am, Markus Heller wrote:
>
> Dear list,
>
> please note that we have uploaded the recordings of all the talks of
> the Software Defined Radio Academy 2017 into our Youtube channel:
>
> ht
I have time-synchronized RTLSDRs using a known, pseudo-random, sequence
injected into the RX inputs using directional couplers. These all had
a common clock so they wouldn't drift apart.
On 2017-08-16 11:57, Derek Kozel wrote:
> It should be pointed out that the hardware based timestamping is
Dear list,
please note that we have uploaded the recordings of all the talks of
the Software Defined Radio Academy 2017 into our Youtube channel:
http://youtube.sdra.io (=forwarder to our channel)
I have just created a playlist of this year's event. The presentations
will follow soon on our webs
It should be pointed out that the hardware based timestamping is only
needed if you need time alignment better than a half second or so. With USB
transfers, various buffers, NTP based alignment of the host computer's
time, and some extra code on the host side you could do a coarse time
alignment, p
Are you trying to do MultiLateration using software defined radio ?
-Original Message-
From: Sylvain Munaut [mailto:246...@gmail.com]
Sent: Thursday, 17 August 2017 1:20 AM
To: b.shube...@sirinsoftware.com
Cc: vk4...@tech-software.net; GNURadio Discussion List
Subject: Re: [Discuss-gnu
On Wed, Aug 16, 2017 at 5:11 PM, wrote:
> What type of hardware? I thought from hardware point of view only precise
> clock is required and all the other things in
> firmware. I've naively thought i could modify hackrf firmware to get this
> feature.
Mostly a FPGA and a PPS input from a GPS re
What type of hardware? I thought from hardware point of view only precise clock
is required and all the other things in
firmware. I've naively thought i could modify hackrf firmware to get this
feature.
On Wed, 2017-08-16 at 17:04 +0200, Sylvain Munaut wrote:
> The USRP have dedicated hardware t
$30 vs $300 $3000
-Original Message-
From: Sylvain Munaut [mailto:246...@gmail.com]
Sent: Thursday, 17 August 2017 1:04 AM
To: b.shube...@sirinsoftware.com
Cc: vk4...@tech-software.net; GNURadio Discussion List
Subject: Re: [Discuss-gnuradio] Time syncing between SDRs on different compu
The USRP have dedicated hardware to support that kind of stuff, the
rtl-sdr and hackrf do not.
That's the kind of advanced features that are cut to reduce the price ...
Cheers,
Sylvain
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In two words - receive signal in two points in space and process them
accordingly to timestamps.
On Wed, 2017-08-16 at 23:40 +1000, vk4...@tech-software.net wrote:
> RTL-SDR has no time - it's a dumb A/D with a XTAL
>
> Same with Hack RF
>
> What ru trying to do
>
> A
>
> -Original Messag
RTL-SDR has no time - it's a dumb A/D with a XTAL
Same with Hack RF
What ru trying to do
A
-Original Message-
From: Discuss-gnuradio
[mailto:discuss-gnuradio-bounces+vk4tec=tech-software@gnu.org] On Behalf
Of b.shube...@sirinsoftware.com
Sent: Wednesday, 16 August 2017 11:22 PM
To:
Hi,
Reading through archive I've found a thread describing how to sync time between
two USRPs on different computers using
set_time_now and set_start_time methods. Unfortunately I have only RTL-SDR now
(and will have HackRF in a few weeks). As
far as I can see there are no such methods in RTL-SD
Thats awesome lots of examples
Sent from my iPhone
> On 16 Aug 2017, at 9:13 pm, Marcus Müller wrote:
>
> Hi Andrew,
>
> the latter. Makes more sense – if the project is a dependency of a flow
> graph, or the flowgraph is the reason the module exists in the first
> place, makes no sense to ha
Hi Andrew,
the latter. Makes more sense – if the project is a dependency of a flow
graph, or the flowgraph is the reason the module exists in the first
place, makes no sense to have it centralized elsewhere; if the flowgraph
is sufficiently complex, it very often happens that you'd end up wanting
Hello
Is there a global repository of .grc files ?
Or do we just rely on examples that come with each project ?
Andrew
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Hi Cinaed,
On 08/16/2017 04:14 AM, Cinaed Simson wrote:
I would replace the 2 serial rational resamplers with one, namely,
(8/1)*(40/614400)=(8/1)*400/614.4) = 5.208/1
or
15.625/3
That is, interpolate by 15.625 decimate by 3.
By which you mean "interpolate by 15625 and
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