Positioning satellite · GPS

GPS BIIF-4

Live position of GPS BIIF-4, propagated with SGP4. A MEO satellite of GPS, catalogue number 39166, period about 718 minutes, inclination 54.46 degrees. To find out whether it is above a given place on the ground, use KUON SKY.

Where it is now

Seen from where you are

Elevation is the angle above the horizon. The closer to 90 degrees, the more nearly overhead it is, the shorter its path through the atmosphere, and the less likely a building or hill is to cut it off. To count with terrain shadow included, use KUON SKY.

Identity

System

GPS

PRN

27

Catalogue number

39166

International designator

2013-023A

Launch year

2013

Shape of the orbit

Orbit class

MEO (medium orbit, where most navigation satellites live)

Period

718 min

Lowest point

19,806 km

Highest point

20,559 km

Inclination

54.46 deg

Eccentricity

0.01417

Element set epoch

2026-08-20 00:01:49 UTC

About this system

Operated by the United States, with the first satellite launched in 1978. It is the longest-serving system in use.

The satellites sit at about 20,200 km, one orbit taking roughly 12 hours, on planes inclined 55 degrees.

Civil signals: L1 C/A, L2C, L5 and L1C.

About the numbers on this page

• Identity and orbit shape are computed from the orbital elements (OMM) published by CelesTrak. They describe the orbit at the element set epoch; the real orbit drifts slowly away from it.
• A satellite launched recently is still moving toward its assigned slot, so its values change from day to day.
• The live position is an SGP4 prediction. Whether the satellite is actually broadcasting a usable signal cannot be told from this calculation.
• The orbit class is decided mechanically from period and inclination, so it may not match the operator's own wording.

CelesTrak GP (OMM) · 2026-08-20

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