alignnorth -- positions the specified antenna to align it using a compass.

SYNOPSIS

alignnorth unit {magnetic/true}

DESCRIPTION

alignnorth positions the specified antenna so that the edge of the antenna dish is pointing in a true north-south line or magnetic north-south line.  The alignnorth command can be issued prior to checking the antenna's alignment.  After the antenna is positioned, the user must check the alignment with a compass.  Any correction to the antenna's position that has been made using the align or autoalign commands will be subtracted from 90.0 degrees azimuth (pointing east).  The correction for magnetic declination will then be added based on the parameters of the command.

PARAMETERS

unit

Specifies the telemetry chain whose antenna is to be positioned.  Telemetry chains are numbered 1,2,3. If no unit is supplied, the default is chain 1.  The chain number must be specified if the option magnetic or true are used.

magnetic

Specifies that the antenna dish will be positioned pointing to magnetic north.  This is the easiest position for aligning the antenna when the compass does not have a magnetic declination correction.

true

Specifies that the antenna dish will be positioned pointing to true north.  This is the default state if no alignment type is supplied.

EXAMPLES

[1]% alignnorth

Positions the antenna associated with chain 1 to point to 90 degrees azimuth, 0 degrees elevation, true north.

[2]% alignnorth 4 true

Positions the antenna associated with chain 4 to point to 90 degrees azimuth, 0 degrees elevation, true north.

[3]% alignnorth 1 magnetic

Positions the antenna associated with chain 1 to point to 90 degrees azimuth with magnetic correction, 0 degrees elevation (magnetic north).

FILES

magnetic_model

SEE ALSO

stowship, autoalign, align, antenna alignment, nmea_monitor

NOTES

alignnorth is not used in conjunction with any other function.  It positions the antenna only.  It cannot be used while the antenna is tracking a satellite or running any other command that controls the antenna.  This command is used by polar satellite tracking antennas only.  Older versions of this command did not have the magnetic option; all positions were with respect to true north.

Last Updated: $Date: 2002/02/08 21:16:31 $