A new adventure in GNSS

Hi,

I am afraid nothing has happened on my GNSS blog for too long now, so I guess I should give some really big news this time ;)
Well, I would love to write about my latest GNSS creation... but I am not allowed :(
I hope this will not happen in the future... in fact, I am now working on a project called One Talent GNSS: a small business to provide GNSS consultancy and "gadgets".

So, this blog will from now on tell more about products and achievements of this new e-Creature, which I hope to grow fast to the size of my passion and enthusiasm!
Check it out regularly, we'll do our best not to disappoint you :)

Michele

Open source Software Defined Radio GPS receiver

Hello,

Just a quick update to the people who are involved on gps-sdr.
Here is a version that (as far as I am aware) compiles on Ubuntu Lucid (32 and 64 bits).
And if you don't have any of NSL's GNSS data grabber, here is file captured with Primo which should give you a position in Nottingham :)

Cheers,
Michele


P.S. Please note that I am not a maintainer of gps-sdr, so please do not ask me for support on how to install the software or other trivial receiver stuff. Also, I don't take any responsibility for the modifications I have done. In practice, take the code you need from it.. and that's about it!

Ladies and gentlemen, our "Wave"

Hi,


This is a special post for me, there is just so much work behind it that I feel literally relieved :)

Figure 1: Wave GNSS front-end.

Luis and me went through a quantity of problems, but eventually this week we can claim that Wave works reliably and performs well.

So here it is, our vision of an industrial direct bandpass sampling, multi-constellation, multi-frequency receiver.

Figure 2: Wave digital board rev1.1 with LVDS, USB, and GigETH connectors exposed.

Figure 3: Wave RF board rev1.1 with dual band filters and variable gain amplifiers

I will not explain the theory behind it, just post a file captured with a Novatel GPS-704X antenna at NSL. With your favourite acquisition algorithm, you may find in there all the currently available satellite navigation signals. And if you know what we are talking about, you know you just need one parameter: f_S = 5.4e8.

By the way, we will be done soon with porting gps-sdr. Wave has already passed the overnight stress test with it on a 64-bit Ubuntu distribution.

Figure 4: gps-sdr processing GPS L1 as digitised and conditioned by Wave. Take a look at the spectrum of the signal on the left (we have a strong external interference at 1.369 MHz, we don't know who's responsible YET). And of course Luis' empty tea mug on the right, filled with champagne later that afternoon :)

We hope readers will find this tool as intriguing as we do. We like to think that we made one step towards the ultimate real-time all-frequencies, all constellations software receiver. Any takers of our challenge?

To be continued,

Luis and Michele

Snapshot post-processing with PRIMO

Hi,

Today I'd like to show what Ben, Luis, and me have been doing in our spare time and sometimes sacrifying our precious weekend hours.

Internal codename RETROFIX, it's a service running on one of our servers and processing small snapshots of data collected with PRIMO. At the moment uses about 200ms of signal and it's therefore limited in sensitivity. But surely it proofs the concept that with a coarse time tag and 128kBytes of digitized RF signal you can calculate the position and the time of a user.

FIG 1: http://www.retrofix.info

If you have a PRIMO dongle just contact me and I'll send you the website address, the configuration files, and the application to grab a compatible signal: I'd love to have some feedback.

Come back soon for updates,
Mic