Sfsatlist1b (binary), Table 196: sfsatlist1b binary message data – NavCom Sapphire Rev.J User Manual

Page 368

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Sapphire Technical Reference Manual Rev. J

368

2.108

SFSATLIST1B (Binary)

SF-3050

Sapphire

SF-3040

This record describes the StarFire satellite constellation, to support a GUI display that shows
the StarFire satellites by ID, look angle, longitude, and mode. This message provides the data
described in the following table, for the standard StarFire satellites, and for any
user-defined satellite that might be defined.

The table will include one Satellite Block for each satellite in the constellation, with
any user-defined satellite as the last entry.

The body of the message is listed in Table 196 with a description of the size of each file.

Table 196: SFSATLIST1B Binary Message Data

Data Item (1 + N * 12)

Data Type

Count of StarFire satellites

U08

Holding for the first StarFire satellite block

StarFire Satellite Block (12 bytes)

Data Type

Satellite ID (320 to 680)

U16

Longitude (-180 to +180 degrees)

R64

Look Angle from present position (~0 to 90 degrees)

U08

Mode (bit-field; see below)

U08

Notes:

1. The count of StarFire satellites will include from zero to sixteen authorized standard

satellites, plus potentially one more user-defined satellite. If the user has selected an
alternate satellite, that status will show up in the Mode field.

2. The satellite ID is the standard name for StarFire satellites, computed as the result of the

value 500 plus the longitude, for example 98 West Longitude becomes 500 + -98 = 402

3. The longitude is minus for West and plus for East

4. The look angle is the calculated elevation from the perspective of a viewer on the ground

at the present calculated position, looking “up” at the satellite. Note that negative look
angles provide no useful information, since the satellite is below the horizon.

5. The mode provides the bits of information defined here:

a. 0x01: Authorized as part of NET 1

b. 0x02: Authorized as part of NET 2

c. 0x04: Potentially unhealthy satellite

d. 0x10: Alternate, meaning this is the selected alternate satellite, one in the StarFire

constellation, or a user-defined satellite.

e. 0x20: User-Defined.

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