Sun Outage Calculator

Sun Outage · Calculator for GEO links

Sun Outage

Twice a year the sun passes directly behind every geostationary satellite. For a few minutes per day its noise swamps the receive antenna. This calculator tells you exactly when – for your hub and every remote site.

—satellite position
—days affected
—longest outage

Satellite & season

Year, season and the satellite's orbit position. A hub preset fills the typical NYNEX teleport values.

Link

Season

Fills satellite, band and hub antenna.

°

Degrees. East positive, west negative.

How a sun outage happens

Drag to rotate

Earth, geostationary orbit and look direction are to scale.

Locations

Click the map to place the selected antenna. Drag to pan, scroll to zoom.

Antennas

Antenna size and position for the hub and one remote site. Leave a set empty to skip it. Look angles update as you type.

Hub antenna

Used in the calendar file.

m
Look angles

—

°

North positive, south negative.

°

East positive, west negative.

Remote site antenna

Used in the calendar file.

m
Look angles

—

°

North positive, south negative.

°

East positive, west negative.

Site list

Paste a list of remote sites – one per line – or load a CSV file. All sites are calculated for the link above. Export as CSV or calendar.

List

Format per line: Name; latitude; longitude; antenna size …

m

How it is calculated

Everything runs in your browser. No server, no API key, no cookies. The model is calibrated on the previous NYNEX calculator.

Geometry

For every minute of the season window the apparent position of the sun (Meeus algorithm, accuracy better than 0.01°) is compared with the look angles to the geostationary satellite. The seconds at which the angular distance drops below the outage threshold are refined to one second.

Threshold

The outage angle grows with the antenna beamwidth (≈ λ/D) plus the apparent radius of the sun. The model is calibrated on the previous NYNEX calculator, so results are consistent with earlier years. Small antennas see longer, wider outages; large antennas short, sharp ones.

Limits

Outage times are given in UTC and in your browser's local time. Actual service impact depends on link margin, modulation and the sun's activity – treat the windows as the period in which degradation is possible. Lower band edge is used as worst case.