ashtech ZY-12 Information Supplement page 37

To set a parameter, push the [e] key and use the arrow keys to move to the
desired parameter. Press the numbered keys, typing zero where necessary.
When a field is full, the cursor automatically jumps to the next one. Press [e] to
save the values and return to Screen 4.
Table 3.8 describes the screen parameters.
Parameter
POS MODE Lets you specify whether to compute altitude or hold it fixed. The field can
contain a value ranging from 0 through 3. To be used for position
computation, a satellite must be higher than the ELV MASK specified on
this subscreen.
• 0 specifies that at least 4 satellites be tracked before the receiver
• 1 specifies that three satellites are locked, the receiver holds altitude
• 2 specifies when the altitude is always held fixed regardless of the
• 3 specifies when 3 satellites are locked, the receiver holds altitude
Remember that when the receiver is first turned on, the altitude is zero. If
position mode is set to a value of 1, 2, or 3, enter a value for altitude in
the POS field of Screen 4.
ALT MODE Lets you specify which altitude to use in an altitude fixed position solution.
This field can contain 0 or 1 value.
• 0 uses last entered altitude or last altitude computed if it was computed
• 1 uses only the altitude entered on Screen 4.
ELV MASK Allows you to set the minimum elevation angle below which no satellite
data are used to compute a position.
FIX UTM Enables or disables the fixing of the UTM zone. This command is used
when you are near a UTM boundary, the receiver is outputting position in
UTM coordinates, and you do not want coordinates to shift from one zone
to another when the boundary is crossed. Must be used in conjunction
with FIX ZONE described below.
PDOP MASK Lets you define the positional dilution-of-precision parameter. The
receiver does not compute position when PDOP exceeds the specified
value. The default is 40.
Screen Descriptions
Table 3.8. Position Fix Parameters
computes position. Altitude is never held fixed (default). The following
settings for POS MODE require a minimum of three satellites to
compute position.
fixed. When more than three are locked, the receiver computes
altitude.
number of satellites tracked.
fixed. When more than 3 are locked and HDOP is less than the
specified HDOP MASK, it computes altitude. When more than 3 are
locked and HDOP is equal to or greater than the specified HDOP
MASK, the receiver holds altitude fixed.
with VDOP less than the specified VDOP MASK, depending on which
altitude is the most recent.
Description
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