Moon, sun and celestial object tracking for EME. A web version of
GJTRACKER
by Lance Collister, W7GJ — find common moon windows between two stations,
with degradation, sky temperature and polarization offset.
Everything is computed in your browser. All times are UTC.
📖 User guide
Date range Section A
Stations Section B
Display
Callsign / Lookup
Locator
Latitude
Longitude
Degrees
Deg
Min
Sec
Dir
Deg
Min
Sec
Dir
Above
Below
With both stations displayed, only the times when both can see the
object are listed — that is the common window. Enter a negative
Above value if your horizon drops away.
Object & operation Section C
0 to 360 shows every azimuth.
Settings Section D
0 = no filter
0 = continuous
Tracking output Planning
Real time tracking Updated every second
--:--:--
Object above the horizonBelow the horizonDashed line = line of sight · the Earth turns as the sub-lunar meridian moves
Activity windowA Asian — first 2 h after moonrise in EuropeE European — from then until moonrise in JapanN North American — the rest
Moon phaseNM new moonFM full moonBoth raise the noise the sun contributes; neither prevents contacts.
Coloursobject above the horizonbelow itDegradation: green ≤2 dB, yellow ≤4, orange ≤6, red worse.
Station directoryEnter a callsign or a locator to begin.
CreditsA web reimplementation of GJTRACKER by Lance Collister,
W7GJ,
whose original program has served EME operators since 1973. Positions follow
Meeus, Astronomical Algorithms, with topocentric parallax correction;
sky temperature is an approximation — see the
guide.