Instructions for people in Ireland pointing Ka band antennas at Saorsat TV service on KA-SAT satellite at 9 deg east orbit position.
In the dynamic map, put your mouse cursor to your location and then double click or simply drag the map. The map image will move so that the chosen point is in the centre. The latitude and longitude of the dot at the centre of the map is then displayed below the map, together with your satellite dish pointing angles: azimuth, elevation and polarisation or skew angle. To improve accuracy, click on the plus sign at the top left side of the map. The scale changes so that you can home in accurately on your location. Repeat several times. Select Map or Satellite view options and see the satellite photo image of the ground or even a view of your own house as seen from space ! Alternatively input your town name, and country if necessary.
1. In the case of KA-SAT, the polarisation is circular, so rotational adjustment amount of the feed system is not required. This represents a major simplification for installation, compared with linear polarisation as used in Ku band. There are two different circular polarisations, right hand circular polarisation (RHCP) and left hand circular polarisation (LHCP). If you are using a Tooway (transmit-receive) satellite internet terminal and have the most recent outdoor TRIAs (model RT4000N-010 or later version) it has an electro-magnetic polarization switch that is designed to operate at least 500 times, so you don't need to change the polarisation manually. You will need a splitter in the receive cable with a DC block on the satellite TV receiver side. If you have a simple receive-only site with an Ka band (20 GHz) LNB you will need to chose the polarisation, either left hand or right hand circular.
2. Set the beam elevation angle (up/down) using the up/down scale on the bracket behind the dish. You may find that it helps to initially set the elevation a couple of degrees higher than calculated to allow for sagging of the dish until everything is tight.
3. For the azimuth angle (sideways) use a magnetic compass or the blue line relative to your house wall, roof edge or garden wall or some local landmark to find the approximate bearing and then swing the dish boldly sideways to find the satellite on the first swing. Then spend half an hour peaking up. Peaking up to the exact centre is really important to minimise outage time during rain.
You need either a Tooway LNB or a Satellite TV receive-only LNB: Circular dual polarisation, Ka band 19.7-20.2 GHz with local oscillator (LO) 21.20 GHz. L band frequencies in the cable are then 1500 - 1000 MHz inverted. Ideally the LNB should have low thermal noise and low phase noise.
On Saorsat you can watch or listen to TV and radio programs:
TV: RTÉ One, RTÉ Two HD, RTÉ News Now, RTÉjr and RTÉ One +.
Radio: RTÉ Radio 1, RTÉ Radio 1 Extra RTÉ 2FM, RTÉ Lyric, RTÉ RnaG, RTÉ Pulse, RTÉ 2XM, RTÉ Choice, RTÉ Gold and RTÉ Chill / Junior.
The beam is assumed to be circular and shown as 0.43 degrees in
diameter at the -3dB contour, as viewed leaving the satellite. Other contours
shown are -1, -2, -3, -4, -5 and -6 dB.
On the -6dB contour you need a dish 1.4 times larger diameter (twice the area), as at the - 3dB contour. There is steep slope in the shape of the beam at and beyond the -6 dB contour, so if the satellite wobbles slightly there will be big changes on level. Do not expect highly reliable service in the outer regions of the beam. Pease advise me of any errors or more accurate information if you know more.
If you put your mouse cursor on the beam type (1 to 4) a message will appear telling you the KA-SAT beam number and the associated terrestrial Gateway (GW1 to GW8).
Safety Warning: The results of this page may be in error, The beam centres and beam shapes and sizes are approximate. The latitude and longitude are not intended for the blind navigation of aircraft, ship or other vehicle purposes. Dish pointing angles may be wrong. Magnetic azimuth bearings are approximate. Use is entirely at your own risk. Apply common sense and don't believe every number that comes out of a computer system. Take care with Tooway satellite dish install and pointing not to injure others by dropping tools or hurting yourself by falling down.
This page is on the satsig.net web site and is strictly
Copyright Satellite Signals Limited (c) 2012 All rights reserved.
Page started 28 April 2012, amended 29 April 2012, amended 18 Dec 2012 V3+key, amended 1 Aug 2015.