GPS Satellite Constellation Nominal Orbit Parameters

05/27/96

Peter H. Dana

Department of Geography, University of Texas at Austin

Send mail to: pdana@mail.utexas.edu

GPS Constellation Nominal Orbit Parameters for Twenty Four Satellites

Four Satellites in each of Six Orbital Planes


Orbit Reference Values (with respect to an epoch of 1 July 1990 00:00:00)

Source: NATO. 1991. NATO Standardization Agreement Navstar Global Positioning System: System Characteristics. 1 February 1991.

ID: Argument of Latitude: Geographic Longitude of Ascending Node: Right Ascension of Ascending Node:

A1 280.7 358.6, 178.6 317.0

A2 310.3 13.4, 193.4 317.0

A3 60.0 248.2, 68.3 317.0

A4 173.4 304.9, 125.0 317.0

B1 339.7 88.1, 268.1 17.0

B2 81.9 319.2, 139.2 17.0

B3 115.0 335.7, 155.8 17.0

B4 213.9 25.2, 205.2 17.0

C1 16.0 346.2, 166.3 77.0

C2 138.7 47.6, 227.6 77.0

C3 244.9 100.7, 280.7 77.0

C4 273.5 115.0, 295.0 77.0

D1 42.1 59.3, 239.3 137.0

D2 70.7 73.6, 253.6 137.0

D3 176.8 126.6, 306.7 137.0

D4 299.6 188.0, 8.0 137.0

E1 101.7 149.1, 329.1 197.0

E2 200.5 198.5, 18.5 197.0

E3 233.7 215.1, 35.1 197.0

E4 335.9 266.2, 86.2 197.0

F1 142.2 229.3, 49.4 257.0

F2 255.6 286.0, 106.0 257.0

F3 5.3 160.9, 340.9 257.0

F4 34.5 175.6, 355.7 257.0

Epoch of 01 July 1990, 0 hours, 0 minutes, 0 seconds.

The argument of latitude is the geodetic latitude of the satellite at the epoch. In this diagram the latitude is expressed as an angle between zero and 360 degrees, starting at the equator and going around the earth through both poles, returning to the equator at 360 degrees.

The geographic longitude of the ascending node is the geodetic longitude where the satellite is at the reference epoch. Since the longitude of each satellite is given independently of latitude, it is given for both sides of the earth (i.e. longitude and longitude + 180 degrees).

The right ascension of the ascending node is the geodetic longitude at which each orbit plane intersects the equator at the epoch.

Nominal Orbit Tolerances

Parameter: Value: Offset: Accuracy: Accuracy(10 year life):

Eccentricity 0 0 less than 0.020 less than 0.020

Inclination 55 deg. 0 +/-0 1 +/- 3

Argument of perigee 0 deg. 0 +/- 180 +/- 180

Longitude of ascending node see table /- 5 deg. +/- 2 +/- 2

Right Ascension of ascending node table +/- 5 deg. +/- 2 +/- 4

Period 717.9882 min

Nodal regression rate -0.04187 deg./day