Datum Select Subscreen - ashtech ZY-12 Information Supplement

After issuing the 990 command, the falling edge of the pulse is synchronized with
GPS time. After issuing the 991 command, the rising edge is synchronized with
GPS time.

Datum Select Subscreen

This option lets you specify the datum of the receiver calculated pseudo-range
option, or input the parameters for a user-defined datum. (The default is WGS-
84.) The datum selected in this screen is only used to compute the position
displayed in screen 2. The position stored in memory is always computed using
datum WGS-84.
The first datum subscreen is reached by selecting DATUM on Screen 4 (Figure
3.16).
Figure 3.16. Datum Select Subscreen
To select a datum, use the arrow keys to highlight the desired datum and press
the[e] key; this captures your selection and exits to Screen 4. You can check your
selection by returning to Screen 2; the selected datum appears in the upper left.
If the datum you want does not appear on this subscreen, highlight MORE and
press the [e] key. When ARF-M is highlighted, press the left arrow to jump the
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Screen Descriptions