Mounting A Satellite Dish Or Rotor

Use decimal degrees or Degrees : Minutes : Seconds?
DMS:

Where is the receiving dish?
Entry method: Grid Reference: Place name: Choose match: Easting: Northing: UK Post Code:	Latitude: Longitude:

System Type?
Fixed or rotor: Satellite: Rotor: Crank:	Meridian Sat Longitude:

How to find azimuth?
Compass, etc: Sun Rise: Sun Set:	Magnetic Variance: Grid Variance: Sun Transit:

How to find dish elevation?
Manufacturers' Scales, etc: Dish Height: Top 2 LNB: Bot 2 LNB: Dish Width: Dish Height:	Dish Offset:
Arm Angle:	Template Angle:

Alignment Settings
TargetMeridian Sat:
Azimuth: GridMag Azim: Rotor Azim: Elevation: Skew:

Rotor & Dish:
Azimuth: GridMag Azim: Tilt: 90 - Tilt: Declination: Elevation: Skew:

Help

If some of the terms or techniques mentioned here are unfamiliar, you are advised particularly to read other pages in this series before use, most particularly the General Introduction - see also the navigator bars at the top and bottom of the page, and the list of useful links below.

If you are unsure of the format for inputting data, hovering the pointer over an input will bring up a short message describing the format expected. In general:

Latitudes, longitudes, grid and magnetic variances can be entered as decimal degrees or DD:MM:SS. In both cases, southern and western values can be entered as negative or by appending S or W, northern and eastern as positive or by appending N or E.
Other angles should be entered as decimal degrees.
Time values for the Sun can be entered as 24 hour HHMM or HH:MM, or as 12 hour HH:MM AM or PM. Seconds values will also be accepted and included, but most published calculations for the Sun are only given to the nearest minute, and greater accuracy than that should not be assumed.
All other data such as grid references and post codes should be entered in their normal format. Irish grid references should be flagged with a leading I.

UK Place Name look up covers UK mainland only. UK Post Code look up should find codes for the entire UK, but to reduce the chances of usage capping by Google, does so by searching the OpenSpace UK mainland database first, only trying Google on failure. Other post codes and places, for example Eire, can be looked up using the World Place Name option, but the database is very US-centric, so append an appropriate country name, for example ,Eire.

The correct non-standard skews for the Hot Bird and Astra satellites, respectively +3.5 & +7.5°, are given, accompanied by yellow warning text - hovering the pointer over the field will display an appropriate message, including the standard skew normally expected.

When you are satisfied with your settings, you can save them by pressing Submit and then bookmarking, marking as a favourite, the resulting URL, the parameters in which will recreate your original settings in the calculator. You may wish to do this once you have positioned a map exactly on your dish site as described below (though you will then have to wait for everything to reload).

Clicking on a map button fixes latitude and longitude as the method of designating the dish location, and creates a map with a marker and azimuth (direction) line for aligning it. Dragging the marker to a new location recentres the map(s) and updates the calculator. Likewise, where necessary, changes in the calculator will be reflected in the map(s). After creating a map, changing settings other than receiver latitude & longitude, or choosing a different satellite, is not recommended and may not be possible.

The Google map has four choices of base layer selectable by clicking the buttons in the top right hand corner. Satellite pictures take significantly longer to load, so it's quickest to use Map to get as close as possible to the intended final location and zoom level before switching to Satellite or Hybrid. If you plan to print the map, please read the Notes.

Satellite images are often subject to perspective distortion, to an extent significant in the context of aligning a satellite dish, thus making their results potentially less reliable than the initial impression given by their appealing simplicity. Work entirely from ground level - position the marker at the point on the ground beneath the proposed dish siting, and choose as aiming point a landmark the base of which is crossed by the line.

For UK mainland nations, there is also an option to create an OS map. OS's OpenSpace® on-line mapping covers UK mainland down to street level (other UK nations are covered by other agencies and are either only available via OS at low-scale or not at all). If, despite the coordinate vetting, you manage to create a map of somewhere not actually covered, the map may just show nothing, or stick on an area on the north east coast, in which case Ctrl-Click the map button to remove it, and just use the Google one. Coordinate conversion between Lat/Lon and E/N doesn't use OSTN02™, so coordinate readouts should only be considered accurate to around 5m.

Notes

Users attempting to use this page via an online language translation service may see messages that *.xml files could not be loaded, but once the messages have been cleared the page should still work normally, although using data hard-coded in the page, rather than that possibly more recent loaded dynamically. The reason for this is that security restrictions in browsers prevent loading XML data from sites other than the page host, and when a page is translated the translation engine rather than the original site becomes the host, therefore any XML data from the latter cannot be loaded.
Magnetic variance is computed by the 2010 World Magnetic Model, with estimated error less than 1° until 2015. Thereafter it will display in red, indicating the model's increasing unreliability over time, in which case you should attempt to get a more recent estimate for your location and enter it manually:
- NOAA's Geophysical Data Center - Geomagnetic Data
- British Geological Survey - World Magnetic Model Calculator
Browser compatibility notes (see also the next note about printing):
- ALL - Maps gobble up resources. If you create both types of map together without letting one complete before starting the other, or, after creating maps, many times change settings in the calculator or drag and zoom forcing continual redrawing, you may find that the Google map becomes blank, or there are jumbled tiles or holes in the OS map, or markers disappear from it, perhaps first from the print preview, then from the map proper. Such problems may resolve themselves given enough time, but now there is also an option to remove a broken map by Ctrl-Clicking the relevant button, so it can be then be clicked again to redraw from scratch. However, particularly as Google Maps do not document a destroy function, it is questionable whether all the resources used are reclaimed when a map is removed, and, especially if you want to print the maps, you may have to reload the page with your chosen final settings, most easily done by clicking Submit on them, before creating one map at a time, allowing each to load fully before creating the next.
- FF - Users of Firebug may experience freezing on (re)loading the page. Either disable Firebug, or halt the frozen page loading (click red cross icon) and then do a full reload (shift-click blue circular arrow). FF2 or earlier, please upgrade to FF3.
- IE8/9 - Despite this webpage being standards compliant, it only functions fully in Compatibility View, which the page sets on loading.
- Opera - Early releases of v10 hung loading this page - please upgrade, or otherwise copy opera:config#Extensions|EcmaScriptJIT into the address bar, press Return, uncheck that item, click Save, and restart Opera.
  
  Opera has a highly idiosyncratic way of handling forms on page reload, the consequence being that when you return to this page using the back button, the page may error, or just the form will be in the state you left it rather than that set by any parameters in the URL. To get round this, once the first reload has completed, reload the page again by pressing <F5> or clicking the Reload button.
Each map is designed to print on a single page of A4 or Letter with top and bottom margins of about 10 to 15mm. This site has better map printing support than many, but generally printing web content is too often neglected, not least by those who create browsers, and maps particularly so. In the past I've reported problems to Microsoft, Opera, Google, and OpenLayers, yet some of the following problems remained long outstanding, though recent testing has shown a marked improvement:
- ALL - Print the Google Satellite Base Layer rather than the Hybrid. The latter tends to look correct in Print Preview but not actually print properly. IE8+ & FF3+ may print it properly, but IE6/7 & Opera print only the map overlay, not the satellite imagery.
- FF3 - Printing individual map pages results in blank maps, you have to print the entire document to get the maps to print properly. Fixed in v3.5.1.
- IE - If you press Print Preview before the map has completely loaded, IE will show a blank preview until loading completes, which may take some time. Some versions of IE can be nudged into showing the Print Preview by altering the zoom.
- Chrome - Earlier versions may insert spurious blank pages.
- Safari - Earlier versions may not print the Google Map - please upgrade to the latest version.
- Opera - Map printing remains abysmal: marker icons may or may not print, vector lines don't print at all, control backgrounds are displaced.

Apologies for these inconveniences.

Useful links (no endorsement of external sites intended nor responsibility taken for their content):

Other pages in this series:
Pages explaining the mathematics behind this calculator:
UK Digital Satellite Television (aka Freesat):
- Freesat
- Freesat from Sky (WARNING: Some might consider this choice of name to be deliberately confusing)
- alt.satellite.tv.europe
General Television:
Other alignment calculator sites:

Many thanks to:

Bill Chadwick, http://wtp2.appspot.com, for the World Magnetic Model and UK Grid Variance scripts, and other help in the OpenSpace Forum;
Christopher Schmidt, crschmidt(at)metacarta.com, of OpenLayers for help with OpenLayers;
Google, OpenLayers, and OpenSpace, for the internet mapping technologies.

Updated	Description
04/10/2011	Added 'universal' option for offset calculation.
05/09/2011	Improved form option locking when maps are drawn. Refinements to site OpenLayers script.
21/07/2011	Updated satellites list.
12/01/2011	Updated satellites list.
27/10/2010	Fixed bug loading DMS values from URL.
11/10/2010	To reduce risk of Google usage capping, altered UK Post Code search to try OpenSpace first, then Google. Significant rewrite of asynchronous script loading. Cut down OpenLayers script and enabled compression for faster loading.
26/06/2010	Fixed bug in reading URL parameters when DMS set. Fixed to work using static data only with common translation engines.
13/06/2010	Added support for Chrome and Safari. Updated Notes appropriately, and to cover Opera 10 hang up.
28/04/2010	Greatly improved support for IE8 wrt map drawing and printing. Updated site scripts for better form handling and asynchronous data loading. Updated satellite data. Added this update record.
01/12/2009	Updated site script handling forms. Updated satellite data.
13/08/2009	Google Map converted to use Google API, rather than OpenLayers API. Upgraded Ordnance Survey map to use OpenLayers v2.8. Fixed problem with colours in <Select> elements in the forms in Opera and IE8. Improved marker dragging and update of calculator. Updated satellite data.
06/01/2009	First major useable version in its current form.

2 Dish & Rotor Alignment Settings Calculator (with internet mapping)

Help

Notes