SatPointer true north reference for dish compass calibration
A compass beside a satellite dish measures direction from magnetic north, while most satellite pointing calculations use true, or geodetic, north. If those references are treated as identical, the dish can sit several degrees away from the correct bearing. The mistake is easy to make in Australia because magnetic declination differs noticeably between Perth, Adelaide, Brisbane, Melbourne and Sydney.
SatPointer combines Google Maps, satellite orbital data and selected installation coordinates to calculate pointing directions for reception, uplink, downlink and mobile satellite use. For a dish compass calibration, its true azimuth supplies the stable north reference, which can be converted to a magnetic bearing for a handheld or phone compass and then checked against signal quality.
| Reference | What the reading means | How to use it for alignment |
|---|---|---|
| True or geodetic north | The geographic north axis; SatPointer’s azimuth basis | Convert it to a compass bearing before using a magnetic compass |
| Magnetic north | The direction toward which a compass needle points | Read the converted magnetic bearing directly |
| Relative heading | A device’s orientation without an absolute north reference | Reject it as the north reference |
Why true north matters
Satellite azimuth is the horizontal direction of the dish, expressed clockwise from true north. Elevation is the angle above the horizon, while skew or roll describes how the reflector must be rotated around the mast. Those three values together describe where a dish should face; changing the compass reference without changing the underlying true azimuth changes only the number shown on the compass.
True north is the north direction of the geographic ellipsoid used for Australian mapping, GDA2020. Magnetic north is where a compass needle points, and the angle between them is magnetic declination. Declination changes with location and slowly over time, so a bearing copied from another city or an old installation note may be wrong even when the compass itself is working perfectly.
Set the installation location
Enter the dish address in SatPointer and place the map pin on the actual mounting point, not the street centre. In a dense suburb such as Parramatta or Melbourne, a few hundred metres can change the coordinates enough to affect the calculation. Check the latitude and longitude against the Australian GDA2020 map reference, and repeat the entry when a rooftop mast is moved several metres.
Choose the satellite used by the service rather than relying on a familiar satellite name. The SatPointer satellite database includes orbital details, beam coverage and estimated dish-size information for supported links. In the Australian market, this matters for Foxtel and Optus reception, Starlink service, mining VSAT and satellite links used by transport operators.
Read the pointing data
After selecting the location and satellite, record the calculated true azimuth, elevation and skew before touching the mast. SatPointer’s orbital calculation gives the direction for the selected link type; an uplink and downlink through different satellites should be treated as separate pointing jobs. Keep the coordinate, satellite and link type with the work order.
For a service already named by a provider, cross-check the footprint in the available satellite listings before setting up a compact dish. Beam contours can place reception outside the intended service area, while the estimated dish size indicates whether a small indoor unit or a larger outdoor reflector is appropriate.
Mobile satellite terminals need particular care because the antenna can move on a truck or mining vehicle while slope and vibration complicate how its heading is read. SatPointer’s mobile-link calculation and the installation instructions should be used together; a handheld compass is not a substitute for a calibrated vehicle heading sensor or the terminal’s own pointing procedure.
Convert azimuth for a compass
Record the current magnetic declination for the installation coordinates. With east declination written as positive and west as negative, use magnetic bearing = true azimuth − declination. For example, if a Sydney site has about 11° east declination and the dish’s true azimuth is 180°, the compass should read about 169°. If the value is 270° and declination is 2° west, the magnetic reading is 272°.
Declination changes materially across Australia. Current values are roughly 11° east in Sydney and Melbourne, 10° east in Brisbane, 8° east in Adelaide, around 2° west in Perth, and several degrees east near Alice Springs. Use the live value for the exact site and installation date because an Internet example can become outdated.
If SatPointer already labels a result as a compass direction, use that converted value and check that you have not also applied declination by hand. If it displays only true azimuth, perform the conversion once, then write both numbers on the installation record so a later technician can audit the source.
Calibrate away from interference
Before following a bearing, calibrate the phone compass away from the vehicle and loose metal objects. Place it flat and use the phone’s calibration routine—often a figure-eight motion—to correct hard-iron and soft-iron errors, then compare it with a second compass. If the two needles disagree sharply, move away from steel and electrical equipment before adjusting the dish.
Australian installations often put antennas on Colorbond steel roofs, reinforced concrete slabs or near parked vehicles, shipping containers and mine equipment. These materials can shift a phone’s magnetic reading without changing true north. Check the compass at the mast, not only beside the receiver, and keep the phone at a consistent orientation during each adjustment.
Do not use the sun’s position or the direction of a satellite as a substitute for the geographic north reference. Geostationary satellites usually cross the northern sky in Australia, but their path says nothing about magnetic declination. Daylight saving in New South Wales, Victoria, South Australia and Tasmania changes the clock, not the magnetic declination.
Set up the dish safely
At the calculated magnetic bearing, turn the mast toward the compass heading and adjust elevation separately. Set skew or roll to the dish design specified by SatPointer or the reflector instructions, because an offset dish can show poor signal despite a correct azimuth. Tighten clamps only after the receiver’s signal meter confirms the selected satellite.
For professional reception, uplink or downlink work, check Australian regulatory requirements before commissioning. ACMA licensing and earth-station rules under the Telecommunications Act 1997 may apply to transmitting equipment and protected frequency use, while receive-only household dishes have different obligations. Mains wiring, grounding and any electrical alteration must meet AS/NZS 3000 and applicable state electrical-safety and wiring rules, so use a qualified electrician where required.
Do not treat an unofficial download as authoritative alignment data. A page such as this unofficial APK page may look convenient, but it should not replace SatPointer’s orbital calculations, a current declination source or verification against the actual signal.
Install, verify and share
After coarse alignment, fine-tune in small increments while watching signal strength and quality, and record the final true azimuth, magnetic bearing, elevation, skew and declination date. Recheck after a mast is serviced, the roof is altered or months pass, since a small physical shift can hide beside a north-reference error.
For an installer or satellite service business, the SatPointer web widget can put live pointing information on a website, blog or support forum. It lets visitors select a location and satellite without sending them through the main interface, making the same reference process available to customers.
Open SatPointer, enter the exact Australian installation address, select the satellite and link type, and record its true azimuth, elevation and skew. Add the current declination, convert to the magnetic bearing, then align the dish and verify the result against live signal quality. Save the completed values with the job record so the same north reference can be reproduced at the next service visit.