Ground station components

Messagede F6DZP » Mar 11 Juin 2013 13:41

Ground station components

Comments – References - Sources



1. Parabolic dish with AZ-EL pointing
The dish shall be mounted for azimuth and elevation pointing and moved by precision motors. with a total system pointing accuracy of 2° or less (including motor precision, antenna alignment, and pointing control software).

The elevation movement shall cover 180 degrees (flip mode capability).
The azimuth movement shall cover 360 degrees or more.
A possible alternative to the flip mode for the elevation movement is the capability of azimuth movement up to 540 degrees to allow for reception of ISS passes over north.
Azimuth angular speed greater than 5°/sec allows for reception of ISS passes up to 90° elevation. Less angular speed will allow reception of passes with lower elevation.
The AZ-EL motors for the main European ground stations are made by Prosistel (http://www.prosistel.it ).
The driver is WISP DDE by CX6DD (http://www.mederoscnc.com/CX6DD/wispdde/wispdde.htm) modified by AMSAT Italia in order to interface Prosistel rotors in the Azimuth extended-range mode. This modified version of WISP DDE also allows automatic sweeping of the antenna around the Sun direction, in order both to check correct Az/El alignment and to measure G/T of receiving system.


2. Tracking software
A number of shareware, freeware, cardware and commercial tracking softwares are available on the web.
Selection of the software shall take care of the capability to drive the AZ-EL motors, flip mode included.
The tracking software used for the on-going tests is Orbitron (http://www.stoff.pl/).


3. LHCP dish feed
ARISS antennas on Columbus are right circularly polarised. Hence, for single reflector antennas, the feed shall be left hand circularly polarised, since each dish reflection reverses the polarisation.
The dish feed can be a patch type or a helix type, positioned in the focus of the parabola.
The dish feed used for ARISS-Europe ground stations is a product of
RF HamDesign ( http://www.rfhamdesign.com )
Type LH-13XL 2.1 - 2.7GHz Connector N-Female 50 ohm

4. LNB
ARISS-Europe ground stations are equipped with an LNB downconverter produced by Kuhne Electronic. The LNB is designed for mast mounting near the parabola.
Two options are suitable :

Option 1 :
KU LNC 25 TM ( centered 2450 MHz)
Frequency range : 2350 – 2550 MHz
IF : 1433.5 – 1633.5 MHz
Amplification : 40 dB
http://www.kuhne-electronic.de/en/produ ... 25-tm.html

Option 2 :
KU LNC 23 TM (centered 2385 MHz) – specific DATV
Frequency range: 2320 – 2450 MHz
IF : 1404 – 1534 MHz
Amplification : 40 dB
http://www.kuhne-electronic.de/en/produ ... 23-tm.html

The KU LNC 23 TM has a notch filter on 1.3 GHz for duplex operation : 1.3 GHz (transmit) and 2.3 GHz (receive). This could be useful from the perspective of a planned cross band voice transponder on Columbus.


5. DVB-S satellite receiver
A suitable DVB-S satellite receiver PCI tuner card is produced by Techno Trend
http://www.technotrend.eu/2920/TT-budget__S2-1600.html

The Techno Trend card fits in a PCI computer slot and supports HD TV (MPEG2 and MPEG4/ H.264) :
• Computer OS : Windows XP, Vista, Windows 7, Windows 8
• CPU for SDTV: at least 800 MHz
• CPU for HDTV: at least P4 3,4 GHz or comparable AMD Athlon (Dual Core recommended) - not needed for Ham TV
• 512MB main storage (1024MB recommended) at least 1GB free hard disc storage
• Graphics card with at least 64MB and DirectX 9 support
• Sound card with DirectX 9 support
Besides the TT-budget S2-1600 card, TechnoTrend produces the TT-S2-3200 card, also suitable.
In addition to the PCI card ground station solution described, it is understood that some specific DVB-S “set top” boxes are able to operate correctly at the symbol rates that will be used by the Ham TV system.


6. Measurement and Display software
Jean Pierre Courjaud F6DZP has developed a free software utility providing radio amateurs and DVB technicians a tool that allows Digital ATV (DVB-S) to be measured precisely. Please see :
page.php?p=tutioune-en

This software comes in two versions :
Tutioune V2.0 for use with the TT S2-3200 card
viewtopic.php?f=60&t=205

Tutioune 1600 V0.1 for use with the TT S2-1600 card
viewtopic.php?f=60&t=214
With the above mentioned setup, Ham Video from Columbus can be received, decoded and visioned on a computer screen. Audio is also available.

7. Noise Power Measurement for antenna alignment
As suggested by Piero Tognolatti I0KPT and with his collaboration, Jean Pierre F6DZP developed a special software for Noise Power Measurement.
With this software, a TT-S2-3200 or a TT-S2-1600 PCI card can be used for Dish alignment by measuring the Sun noise on S-band.
viewtopic.php?f=67&t=212

8. Streaming video on the Internet
For H264 encoding and streaming video on the Internet, several software solutions exist:
• Adobe Flash Media Live Encoder (FMLE) – free – Win XP, Win7, Win8
• FFsplit – free – Win7, Win8
• Open Broadcaster (OBS) – free – Win7n Win8
• Xsplit – only basic functions are free – Win XP, Win7, Win8
Under Windows XP, the best solution is FMLE.
For H264 encoding and streaming, a good Dual Core or a Quad Core CPU is needed.
Sending the video stream, produced by the DVB-S receiving software, to the Internet encoder/streamer software (FMLE, OBS…) needs additional software such as Vcam.
The general ground station setup is shown in the two appended charts :
• Solution 1 : based on a DVB-S PCI card
• Solution 2 : based on Set Top Box with Ethernet output
F6DZP
 
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Re: Ground station components

Messagede F6DZP » Ven 6 Sep 2013 14:13

TT S2-1600 works on a PC with a PCI slot or a PCIexpress slot using a Startech PEX1PCI1 adaptor.
tested with Tutioune or NPM.

Jean Pierre F6DZP
F6DZP
 
Messages: 615
Inscription: 24 Déc 2010

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