Observability

An object is observable when three geometric conditions hold, then detected when its signal-to-noise ratio reaches 5.

From the ground

Condition	Default	Verdict when it fails
The station is dark enough: Sun below the limit	−12°	Station in daylight
The satellite is above the minimum elevation (apparent, refraction included)	10°	Below the minimum elevation
The satellite is sunlit	—	In the Earth’s shadow

From orbit

When the observer is a satellite, the daylight and elevation rules are replaced:

Condition	Default	Verdict when it fails
The line of sight does not cross the Earth and its atmosphere (100 km), and clears the limb by a minimum angle	5°	Hidden by the Earth / too close to the limb
The line of sight is far enough from the Sun	40°	Sun too close to the line of sight
The target is sunlit	—	In the Earth’s shadow

Both sets of limits are in the Sensor tab.

Detection

When the geometry allows it, the verdict becomes Observable if the SNR is at least 5, otherwise Below the sensor limit. A saturated badge appears when the brightest pixel exceeds the full well of the detector. See Sky and SNR.

Next window

When the object cannot be observed, a banner explains why and searches the next observable window over 48 hours, with a button to go there. In orbit mode, the Geometry tab also lists the observable passes of the next 48 hours.