The Aero Thread..

[Analoguesat]

Slightly OT

Has anyone tried ShipPlotter? ShipPlotter

Im too far from the coast to try that one - any ship trying to come up the River Tweed will be in serious trouble up here - its only a few feet deep

 

[smoggy07]

Yes, been running it since the very first release in December 2004.

Is it any good coverage wise? I've got the ShipFinder app on my phone and can plot them coming in and out of Teesport when I pick them up on VHF talking to Tees VTS

Im too far from the coast to try that one - any ship trying to come up the River Tweed will be in serious trouble up here - its only a few feet deep

 

[aceb]

Is it any good coverage wise? I've got the ShipFinder app on my phone and can plot them coming in and out of Teesport when I pick them up on VHF talking to Tees VTS

That depends on how far from the coast you are, how high, what equipment you use blah blah. But, from here overlooking the Channel with a 2x5/8 colinear 60 miles is typical range when conditions are flat. During tropo that can push out as far as the north coast of Spain and southern Ireland.

This grab is typical summer time range during good weather.

 

[spacedish]

Bit OT , but I decided to try my 90cm Greg on C Band AERO , but fell at the first fence. We had a power cut last week and the mains surge that followed fried my LT8700 which I used as a remote positioner :O(
This is the third LT I have lost to mains surges following power cuts.

Anyone using the Titanium SC1 as a positioner ? Won't be able to use it remotely but it seems like the only alternative.

 

[Llew]

Bit OT , but I decided to try my 90cm Greg on C Band AERO , but fell at the first fence. We had a power cut last week and the mains surge that followed fried my LT8700 which I used as a remote positioner :O(
This is the third LT I have lost to mains surges following power cuts.

Anyone using the Titanium SC1 as a positioner ? Won't be able to use it remotely but it seems like the only alternative.

You can usually pick up an RX/Positioner on fleabay. For instance, this AD3000IP now -

http://www.ebay.co.uk/itm/301934304703?rmvSB=true

 

[spacedish]

Thanks Llew that looks promising.....especially if it uses the same positioning system as the 8700
I have had three LTs off ebay in the past , but they are now hard to get hold of.

Stupid thing is , after the power went off I unplugged just about every appliance in the house to avoid the surge....but forgot the LT in the garage .That'll teach me !

 

[John]

Bit OT , but I decided to try my 90cm Greg on C Band AERO , but fell at the first fence. We had a power cut last week and the mains surge that followed fried my LT8700 which I used as a remote positioner :O(
This is the third LT I have lost to mains surges following power cuts.

Anyone using the Titanium SC1 as a positioner ? Won't be able to use it remotely but it seems like the only alternative.

Shame about the 8700 John, they were well ahead of their time on the positioner software. Still use one here to drive a 1.2 CM dish for Ku.
Re: the TiT ASC1 ..... also have one of those for use on my 1.8 CM, it's well built but know where near as versatile and very prone to software crashing and pulse mis-counts which totally screws up your sat positions. I managed to get mine to be reasonably stable by doing the recommended additions of caps & ferrite rings etc on the control cables and earthing requirements to the dish mount / coax's etc. The pc channel editor is useful but it can be a bit of a pain to re-sync your sat positions if it has a wobbly. I'm using a Moteck for the 1.8 CM at the moment, the ASC1 is on the side line until i make my mind up which one to settle on.

 

[spacedish]

Thanks John
I had read about the probs with the SC1 and your comments seem to have confirmed my doubts.
As Llew suggests I'll trawl ebay for one of the golden oldies :O)

 

[Vipersan]

So ...at the moment I have the loop output split through a pssive filter ....one output going to SDRplay ....the other output to Airspy ..
I do have 2 different versions of SDR# running as one O/s is 64bit ...the other 32bit ..plus later versions of SDr# dont support SDRplay ..
That said I have the bandwidth set the same on each version ...and 2 versions of Jaero ..
Again one is 64bit the other 32bit...
Apart from that they receive the same Cband data ..
The reason for going to this much trouble ?
Well ..since I got Airspy ...I have had difficulties decoding the data ,,,
So I wanted to see if one receiver is more sensitive that the other ..
Well..
From my observations ..SDRplay IS indeed either a little more sensitive ....
Both receivers get more than I would like of bad R/T packets ..
but oddly Airspy totally misses packets that SDRplay picks up ...
So when the data is borderline ..SDRplay has the edge ..
This could be due to the SDRplays built in LNA ...
Does Airspy have one ?
Certainly there is a tickbox for one but is this an addon ?
19:32 flight SN359

both recivers picked this up ..
..but moments later the SDRplay logged another flight that the Airspy missed ?

I belive this is down to the SNR ..
Noted that the noise flo0r of the Airspy is naturally at 40db
Wheras the noise floor of the SDRplay is at 30db
Visibly the signals 'stand out' much more clearly on the waterfall when using the SDRplay.
It will be interesting I suppose to compare to an RTL dongle.
..anyone else have similar findings ..?
please discuss..
This is such a knife edge type system with so many variables in play ...that we need to be armed with all informations when choosing equipment when considering a permanent station.
Finally..
Such a shame the Inmarsats are in inclined orbits as all 3 in my visible arc are at least possible for part(s) of the day ..weather permitting ...on a 1 mtre dish.
rgds
VS

 

[s-band]

A few thoughts:

This could be due to the SDRplays built in LNA ...
Does Airspy have one ?

It's internal to the R820T front end

I belive this is down to the SNR ..

Yes, but, the max SNR achievable is set by the dish and LNB. The gain of the LNB is so high that as long as you are seeing at least 10dB noise from it when you switch it on and off you will not gain anything by adding more gain in your IF (the SDRs)
The SNR will also be affected by the back end bandwidth but that is set in JAERO.

Visibly the signals 'stand out' much more clearly on the waterfall when using the SDRplay.

Are the FFT parameters the same? They need to be if you are doing a comparison.

If a signal is close to threshold, it could be randomly decoded by one and not the other because of the nature of noise etc. If both are on the same PC, there could be timing issues due to processing, especially if running Airspy at 10Ms/s

 

[scopus]

Thanks Llew that looks promising.....especially if it uses the same positioning system as the 8700
I have had three LTs off ebay in the past , but they are now hard to get hold of.

Stupid thing is , after the power went off I unplugged just about every appliance in the house to avoid the surge....but forgot the LT in the garage .That'll teach me !

I have an old Strong analogue receiver up the loft, with positioner you can have with pleasure, built like a brick s##t house and weighs a ton if that is of any use....

 

[Llew]

Shame about the 8700 John, they were well ahead of their time on the positioner software. Still use one here to drive a 1.2 CM dish for Ku.

After my first positioner, a standalone Pace job, I had an SR8700 for a number of years before a succession of AD3000's (corrupt eeproms in two of them - a known problem with this box).
What I liked about the 8700 was the auto peaking for best position on a satellite. Sadly analogue only, could do with an AGC line from a positioner for a similar facility on digital signals.

 

[s-band]

Virtual Radar Server - Preview Edition Updated for JAERO etc
The author has just posted this Extended timeout for Inmarsat data (JAERO) - Virtual Radar Server Forums Make sure you use this download: http://www.virtualradarserver.co.uk/Preview.aspx
He has added separate time-outs for JAERO. I think that the normal "remove from tracking" still needs to be set long if you want to join mode-S with JAREO tracks outbound from the mode-S coverage.

 

[s-band]

15W coverage
Whilst testing the new version of VRS (works well for me), for the first time I saw traffic south of the equator. I have seen an occasional plane but earlier this PM I was seeing a lot in the South Atlantic and one off the coast of Chile. At the time, I was getting Eb/No of 11-15dB compared to my normal 5-12dB. I wondered if RX footprint is biased to the north or if Inmarsat switch traffic around the satellites or did I just time it well by looking when the sat was in the sweet spot? What coverage to others get?

 

[Vipersan]

15W coverage
Whilst testing the new version of VRS (works well for me), for the first time I saw traffic south of the equator. I have seen an occasional plane but earlier this PM I was seeing a lot in the South Atlantic and one off the coast of Chile. At the time, I was getting Eb/No of 11-15dB compared to my normal 5-12dB. I wondered if RX footprint is biased to the north or if Inmarsat switch traffic around the satellites or did I just time it well by looking when the sat was in the sweet spot? What coverage to others get?

Generally the traffic I get from 15W is atlantic traffic ...but surprise surprise this morning I saw a plane at the extreme East of the PP map ..
ie ..heading East from the Asian landmass ..
I sadly didn't have time to grab a screenshot ...but certainly it surprised me ..
??
Deadly quiet for me currently at 15W ..
I have changed nothing ..so have to assume we are well past the 'sweet spot ' atm ..

Having said that ..I'm getting data again ..but no 'plots' as yet ...having corrected for T channel drrrriiiffft...
Just got jaero response from BAW6NC (AW6NC) 56.9 long -19.8 lat ...at 19:08 ... but just appeared on the map..
rgds
VS

 

[scopus]

Been playing with the 1.2 Greg for C band and Immarsat at 15W, works really well, really pleased with the results..

 

[s-band]

Having said that ..I'm getting data again ..but no 'plots' as yet ...having corrected for T channel drrrriiiffft...

I think you may have drifted - I was getting about 40 in N Atlantic at the time of the last message.
I get about 4kHz drift sunny day to cool night which is just about OK. However, the LNBF is in a plastic bottle "greenhouse" which is probably not a good idea! I think the lite version of the Tit is more stable because it doesn't have the heat sink to warm it up. Both have a TCXO.

 

[Vipersan]

Well ..fwiw I have cut the relevant bits for my 1.546.082 patch antenna ..and part assembled it ..
sadly I need a few M1.6 nuts to finish the job ..
(on order) ...this Patch I hope will be tested by removing the C band lnb position at 15W on carl ..and crudely mounted in its place when completed...
Testing times I think..
lol
..and yes it is taped to the front of my telescope atm ..
lol

 

[Vipersan]

Well ..I've downloaded the latest X64 version from the link above ..but after trying for well over an hour ...I just can't make VRS work with Jaeros output ..
I'm either missing something very obvious ..or I'm just too stoopid.
I figured it was as simple as adding a second 'receiver' with port setting 127.0.0.1 /30003
Enabling ads ouput in jaero port 30003 ...

Sadly no ...it is more complex than that.
Also since I added a second receiver ..and poked around in VRS settings ..I can no longer plot 'local' planes mode-s
I can fix that by reverting I guess..but that still leaves me mystified regarding adding both Mode-S and acars/jaero on a combined feed ..
Any chance of some screen grabs of various important page settings ...or just a walkthrough description of the changes needed..
I know SB has sorted this ...
but it is not obvious to me..
rgds
VS

 

[spacedish]

Nice work Chris !!!!

Been playing with the 1.2 Greg for C band and Immarsat at 15W, works really well, really pleased with the results..View attachment 93019 View attachment 93020 View attachment 93021