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Commands Summary

90

 MiLLennium GPSCard Software Version 4.50 Command Descriptions Manual Rev 1

This command has a two-fold function:

(1)

to set the maximum age of differential data that will be accepted when operating as a remote station.  Dif-
ferential data received that is older than the specified time will be ignored.  When entering 

DGPS

 delay,

you can ignore the ephemeris delay field.

(2)

to set the ephemeris delay when operating as a reference station.  The ephemeris delay sets a time value
by which the reference station will continue to use the old ephemeris data.  A delay of 120 to 300 seconds
will typically ensure that the remote stations have collected updated ephemeris.  After the delay period is
passed, the reference station will begin using new ephemeris data.  To enter an ephemeris delay value,
you must first enter a numeric placeholder in the 

DGPS

 delay field (e.g., 2).  When operating as a reference

station, 

DGPS

 delay will be ignored.

dgpstimeout 15

dgpstimeout 2,300

NOTE 1: The 

RTCA

 Standard for 

SCAT

-

I

 stipulates that the maximum age of differential correction messages

cannot be greater than 22 seconds.  Therefore, for 

RTCA

 logs, the recommended 

DGPS

 delay setting is 22. 

NOTE 2: The 

RTCA

 Standard also stipulates that a reference station shall wait five minutes after receiving a new

ephemeris before transmitting differential corrections.  This time interval ensures that the remote
stations will have received the new ephemeris, and will compute differential positioning based upon the
same ephemeris.  Therefore, for 

RTCA

 logs, the recommended ephemeris delay is 300 seconds.

DGPSTIMEOUT  dgps delay

ephem delay

DGPSTIMEOUT

Command

dgps delay

min.

2

max.

1000

Maximum age in seconds

60

ephem delay

min.

0

max.

600

Minimum time delay in seconds

120