Example Data Table
These examples use sample declination values. Replace them with your current local value for final compass work.
| Example |
Latitude |
Longitude |
Satellite Longitude |
True Azimuth |
Elevation |
Skew |
Magnetic Heading |
| Lahore sample |
31.5204° |
74.3587° |
83.0° |
163.79° |
52.10° |
13.77° |
162.79° SSE |
| London sample |
51.5072° |
-0.1276° |
28.2° |
145.44° |
25.37° |
20.67° |
145.44° SE |
| New York sample |
40.7128° |
-74.0060° |
-101.0° |
217.99° |
35.40° |
-27.81° |
230.99° SW |
Formula Used
The calculator assumes a geostationary satellite above the equator. Site latitude is
φ. Longitude difference is Δλ = satellite longitude - site longitude.
Elevation is calculated as
atan((cosφ × cosΔλ - Re/Rs) / sqrt(1 - (cosφ × cosΔλ)²)).
Here Re is Earth radius, and Rs is geostationary orbital radius.
True azimuth is calculated with
atan2(sinΔλ, -sinφ × cosΔλ), then normalized to 0–360 degrees.
Magnetic heading is true azimuth - magnetic declination.
Feed skew uses atan2(sinΔλ, tanφ). Slant range uses the law of cosines.
Free space path loss uses 92.45 + 20log10(distance km) + 20log10(frequency GHz).
Why Look Angles Matter
A satellite dish does not aim at the sky by guesswork. It follows a narrow geometric line. Small heading errors can remove signal margin. Rain, cable loss, and nearby trees make that margin even more important. This calculator turns a site location and a satellite longitude into practical field angles. The azimuth shows the true compass direction. The elevation shows how high the beam rises. The skew value helps rotate the feed for correct polarization.
Better Planning Before Installation
Installers often lose time when a wall, roof edge, tree, or pole blocks the dish path. The obstruction fields give a fast clearance check. Enter the distance to the object and its height. The tool compares that height with the beam line from the dish center. A positive clearance means the beam passes above the object. A negative value means the path is blocked. The result is an estimate, yet it is useful before drilling mounts or running cable.
Heading And Alignment Notes
True azimuth is measured from geographic north. A handheld compass points to magnetic north. Local magnetic declination can shift the reading by several degrees. East declination is entered as positive. West declination is entered as negative. The calculator then gives a magnetic heading for compass work. Use that value as a starting point. Then peak the signal with a meter or receiver quality screen.
Advanced Use
The slant range estimates the distance from your dish to the geostationary satellite. The frequency field estimates free space path loss. This value helps compare bands and link budgets. Offset dish tilt is also estimated. Many small dishes use an offset reflector, so the face does not point exactly where the beam points. Always check the dish scale and manufacturer instructions. Use solid mounts. Tighten bolts gradually. Recheck level after each adjustment. Record final values with the download buttons. Good notes help future service visits and repeated installations.
Safety Checks
Before climbing, confirm safe access and weather. Keep the mast plumb on both axes. A tilted mast changes every reading. Mark the starting heading with tape. Move the dish slowly. Wait for receiver quality to update between turns.
FAQs
What is satellite dish azimuth?
Azimuth is the left or right direction of the dish. It is measured in degrees from north. This calculator shows true azimuth and compass-adjusted magnetic heading.
What is elevation angle?
Elevation is the upward angle above the horizon. A low elevation needs a clearer path. Buildings, trees, and roof edges can block the beam.
What does LNB skew mean?
LNB skew is the feed rotation angle. It helps match satellite polarization. Receiver or dish markings may use the opposite sign, so confirm your equipment convention.
Should I use true or magnetic heading?
Use true azimuth for maps and satellite charts. Use magnetic heading when aiming with a compass. Enter local magnetic declination to convert between them.
Why is my satellite below the horizon?
A geostationary satellite may not be visible from every place. If elevation is zero or negative, the satellite is beyond the local horizon.
What is obstruction clearance?
Clearance estimates how far the beam passes above an object. Positive clearance is better. Negative clearance means the entered obstacle blocks the estimated path.
What is slant range?
Slant range is the straight-line distance from your dish to the satellite. It is used for delay estimates and free space path loss calculations.
Is this enough for final alignment?
This calculator gives strong starting values. Final alignment should be peaked using a signal meter, receiver quality reading, and the dish maker’s instructions.