Skip to content

Satellite Tracking

FBSAT59 computes real-time satellite positions and pass predictions with Skyfield. This page describes the tracking views; setting your location is in Setup — Step 1.

The tracking views

The centre of the window is a set of tabs. Four of them show the selected satellite:

Tab What it shows
Dashboard A local map zoomed onto the selected satellite's footprint (updated every second) beside a compact radar, with a one-line readout: elevation, azimuth, range, downlink/uplink, mode
World Map The whole world with every tracked satellite as a coloured dot, plus your QTH. The selected satellite's ground track is drawn as a yellow line when View → Show Ground Track is on
Radar A full sky view (azimuth around the rim, elevation as rings from horizon to zenith) with the satellite's position and its AOS→LOS arc
Pass Chart Elevation vs. time for the selected satellite's upcoming passes; a red vertical line marks now

Group Pass Chart appears after a Group pass search and shows the same elevation-vs-time view for a whole group.

Selecting a satellite in the left-hand list drives all of these at once.

Dot and text colours

In the satellite list and on the maps, colour indicates operational status, not visibility:

Colour Meaning
Green (bold) AMSAT: operational
Yellow AMSAT: partially operational
Red AMSAT: non-operational
Orange SatNOGS reports it alive; no AMSAT data
Purple (italic) Provisional object (NORAD ≥ 90000) still awaiting a TLE — position not shown yet
Grey Status unknown
Blue Celestial body (Moon); bold when above the horizon

The full legend is under Help → Satellite/Transmitter Colors.

Pass predictions

Upcoming passes are in the Upcoming Passes panel at the bottom of the window, which has two tabs:

  • Target — passes for the currently selected satellite
  • Group — passes for every satellite in the current list filter

Set the From / To range (or use the quick-range dropdown: +6h, +24h, +3d, +7d, +30d), then click Search. The Group tab also has a Min El: control (default 5°). Export CSV saves the results.

Each row shows AOS, TCA, LOS, maximum elevation, duration and a quality rating:

Quality Max elevation
Excellent ≥ 60°
Good ≥ 30°
Fair ≥ 10°
Low < 10°

TLE (orbital element) data

Positions are computed from TLE sets. FBSAT59 keeps them fresh automatically.

Sources

  • CelesTrak — six group feeds, each on its own refresh interval:
Group Interval
Space Stations 1 h
Amateur Satellites 2 h
CubeSat 4 h
Weather Satellites 6 h
Earth Observation 12 h
Science Satellites 12 h

Enable or disable groups in File → General Settings → TLE Sources.

  • SatNOGS — per-satellite lookup, used on demand and for provisional objects.

There is no Space-Track integration. AMSAT is used for operational status, not orbital elements.

Updating and checking

  • Satellite → Update TLE forces an immediate refresh of the enabled sources.
  • Satellite → Add Manual TLE… lets you paste a set by hand.
  • Right-click a satellite → Satellite Info… shows that satellite's TLE epoch, quality score, source and group.
  • Help → Clear TLE Sync History… makes the next fetch re-download everything.

The satellite list

The left panel is a filter dropdown, a search box and the list itself.

  • Filter dropdown — All Satellites, your ★ <custom group> entries, then the fixed categories: Amateur, CubeSat, Weather, Earth Observation, Science, Space Stations, Operational (AMSAT), Celestial Bodies, Hidden.
  • Search box — type part of a name to filter live.
  • Right-click a satellite — ★ Favorite Groups, Hide / Unhide, Satellite Info…, Open in SatNOGS, Deselect Satellite.

The database is populated and kept current from the CelesTrak groups above, so its size depends on which groups you have enabled.

Favorite groups

  1. File → General Settings → Custom Groups — Add Group (creates Favorite N; double-click to rename).
  2. Right-click a satellite → ★ Favorite Groups → pick the group.
  3. Choose that ★ <group> entry in the filter dropdown to show only its members. Removing a group unassigns its satellites.

Transmitters

Frequencies come from SatNOGS. For the selected satellite they appear in the Transmitter dropdown on the Radio Control tab; picking one sets the downlink/uplink and mode. Add, edit or remove local entries from the Satellite menu (Add / Edit / Delete Transmitter…); a manual entry overrides the SatNOGS one. Refresh the database with Satellite → Fetch Transmitter Database.

Doppler correction

When a transponder is selected on the Radio Control tab, FBSAT59 recomputes the Doppler shift every second and retunes the connected rig so the received frequency stays constant. Turning Lock on (Ctrl+L, or the L button) hands downlink tuning to you so you can work anywhere inside a linear transponder's passband, with the uplink kept paired; turning it off resumes automatic correction. Details: Radio Control — Lock.

Next steps