------------------------------------------------------------

Simple Text Output Format:

The simple text (ASCII) output contains time, position, and velocity data in
the fixed width fields (not delimited) defined in the following table:

    FIELD DESCRIPTION:      WIDTH:  NOTES:
    ----------------------- ------- ------------------------
    Sentence start          1       Always '@'
    ----------------------- ------- ------------------------
   /Year                    2       Last two digits of UTC year
  | ----------------------- ------- ------------------------
  | Month                   2       UTC month, "01".."12"
T | ----------------------- ------- ------------------------
i | Day                     2       UTC day of month, "01".."31"
m | ----------------------- ------- ------------------------
e | Hour                    2       UTC hour, "00".."23"
  | ----------------------- ------- ------------------------
  | Minute                  2       UTC minute, "00".."59"
  | ----------------------- ------- ------------------------
   \Second                  2       UTC second, "00".."59"
    ----------------------- ------- ------------------------
   /Latitude hemisphere     1       'N' or 'S'
  | ----------------------- ------- ------------------------
  | Latitude position       7       WGS84 ddmmmmm, with an implied
  |                                 decimal after the 4th digit
  | ----------------------- ------- ------------------------
  | Longitude hemishpere    1       'E' or 'W'
  | ----------------------- ------- ------------------------
  | Longitude position      8       WGS84 dddmmmmm with an implied
P |                                 decimal after the 5th digit
o | ----------------------- ------- ------------------------
s | Position status         1       'd' if current 2D differential GPS position
i |                                 'D' if current 3D differential GPS position
t |                                 'g' if current 2D GPS position
i |                                 'G' if current 3D GPS position
o |                                 'S' if simulated position
n |                                 '_' if invalid position
  | ----------------------- ------- ------------------------
  | Horizontal posn error   3       EPH in meters
  | ----------------------- ------- ------------------------
  | Altitude sign           1       '+' or '-'
  | ----------------------- ------- ------------------------
  | Altitude                5       Height above or below mean
   \                                sea level in meters
    ----------------------- ------- ------------------------
   /East/West velocity      1       'E' or 'W'
  |     direction
  | ----------------------- ------- ------------------------
  | East/West velocity      4       Meters per second in tenths,
  |     magnitude                   ("1234" = 123.4 m/s)
V | ----------------------- ------- ------------------------
e | North/South velocity    1       'N' or 'S'
l |     direction
o | ----------------------- ------- ------------------------
c | North/South velocity    4       Meters per second in tenths,
i |     magnitude                   ("1234" = 123.4 m/s)
t | ----------------------- ------- ------------------------
y | Vertical velocity       1       'U' (up) or 'D' (down)
  |     direction
  | ----------------------- ------- ------------------------
  | Vertical velocity       4       Meters per second in hundredths,
   \    magnitude                   ("1234" = 12.34 m/s)
    ----------------------- ------- ------------------------
    Sentence end            2       Carriage return, '0x0D', and
                                    line feed, '0x0A'
    ----------------------- ------- ------------------------

If a numeric value does not fill its entire field width, the field is padded
with leading '0's (eg. an altitude of 50 meters above MSL will be output as
"+00050").

Any or all of the data in the text sentence (except for the sentence start
and sentence end fields) may be replaced with underscores to indicate
invalid data.