Difference between revisions of "Es'hail-2 Ground Station"

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== RF System ==
 
== RF System ==
  
"[Block Diagram Here]"
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[[File:GHY RF System Block V1.jpg|800px]]
  
 
=== Dish ===
 
=== Dish ===
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== Computer System ==
 
== Computer System ==
  
[[File:GHY RF System Block V1.jpg|800px]]
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"<block diagram here>"
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=== Hardware ===
 
=== Hardware ===
  

Revision as of 15:54, 16 February 2019

The BATC & AMSAT-UK QO-100 (Es'hail-2) WebSDR & Spectrum Monitor are located at the iconic Goonhilly Earth Station in Cornwall (IO70JB).

The Narrowband WebSDR can be accessed at https://eshail.batc.org.uk/nb/, the Wideband Spectrum Monitor at https://eshail.batc.org.uk/wb/

GH view.JPG GH room.JPG GHY2 Desk.jpg

The equipment is housed in a room dedicated to amateur radio infrastructure in the original control building for the now defunct GHY2 90 ft dish antennae, built in 1969.

As well as the Es'hail-2 (now known as Qatar Oscar 100) WebSDR and spectrum monitor, the station houses an AMSAT-UK Funcube ground station and an HF Kiwi WebSDR with GPS TDOA.

RF System

GHY RF System Block V1.jpg

Dish

The original dish installed in August 2018 was a consumer model and suffered damage in strong winds during October 2018.

This was replaced in January 2019 with a heavy duty Hirschmann 1.3m offset dish.

GHY200 Dish.JPG GH Dish.JPG

RF Front End

A modified Octagon quad LNB is mounted on the dish and locked to the 25 MHz output from a Leo Bodnar GPSDO.

See https://wiki.batc.org.uk/Es%27hail-2_LNBs_and_Antennaes for more details on the locking modifications

The 25 MHz reference is fed to the LNB through a dedicated coax run, and 2 further coax runs are used to feed separate horizontal & vertical feeds back to the equipment room.

Receivers

2 separate AirSpy USB SDR Receivers, locked to a 10MHz output from the LeoBodnar GPSDO, are used for the WebSDR and Spectrum monitor.

MainTray2.jpg


RearPanel2.jpg

GPS reference

The GPS reference is a Leo Bodnar unit, running firmware version 1.12, programmed to produced 10 MHz (for the Airspys) and 25 MHz for the LNB. The settings for the reference to produce these 2 frequencies were not straightforward (as the 2 outputs on the Leo Bodnar unit need to be linked) but are here for reference:

Computer System

"<block diagram here>"

Hardware

The WebSDR & Spectrum Monitor both run off a single machine with the following hardware specification:

  • Intel i7-2600 CPU
  • 16GB DDR3 RAM
  • Intel DQ67SW Motherboard
  • 500GB Samsung 850 EVO SSD

Software

  • Ubuntu Server 18.04
  • Nginx Web Server & Reverse Proxy
  • WebSDR by PA3FWM (homepage)
  • FFT Spectrum Server (source coming soon)

Networking

Goonhilly Earth Station has 2x diverse redundant 10Gb links into JANET PoPs. They have been kind enough to give us a dedicated IP address and access to >300Mb/s of up & down bandwidth for use by the station.

A pfsense firewall running on a PC Engines APU2D4 board is used as the station router & firewall.

A high-bandwidth Leo Bodnar NTP Server also provides NTP service to the station & the worldwide NTP Pool.