ashtech Z-FX, Operation And Reference Manual

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Introduction 3
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Functional Description
The receiver is activated when power is applied to the power connector (or internal
battery has been inserted for the Z-Surveyor only), and the power push-button is
pushed to ON. After self test, the receiver initializes its 12 channels and begins
searching for all space vehicles (SV) within the field of view of the antenna.
The receiver can track all Block I and Block II GPS SVs. All 32 PRN numbers as
specified in Navstar GPS Space Segment/Navigation User Interfaces, ICD-GPS-200,
Revision B are coded inside the product. As the receiver acquires (locks onto) each
SV, it notes the time and then collects the ephemeris data about the orbit of that SV,
and almanac data about the orbits of all the SVs in the constellation.
The receiver features 12-parallel channel/12-SV all-in-view operation; each of up to
12 visible SVs can be assigned to a channel and then continuously tracked. Each SV
broadcasts almanac and ephemeris information every 30 seconds, and the unit
automatically records this information in its non-volatile memory.
The unit has an L1/L2-band radio frequency (RF) port and four RS-232 serial input/
output (I/O) ports. Ports A, B, C, and D are capable of two-way communication with
external equipment with Port D capable of RTCM operation when using the optional
internal radio link.
The RF circuitry receives satellite data from a GPS antenna and LNA via a coaxial
cable, and can 5V to the antenna/LNA by means of that cable. No separate
antenna power cable is required. Typical power consumption is approximately 7.5
watts even when powering an LNA.
The receiver incorporates a green-colored LED which lights indicating power status
by flashing. A flashing red light indicates sleep mode. A second green-colored LED
below the first one indicates operation of the optional internal spread spectrum radio
by flashing.
The receiver collects Coarse Acquisition (C/A) code-phase (pseudo-range) and full
wavelength carrier phase measurement on L1 frequency (1575 MHz), Precise (P)
code phase (pseudo-range) and full wavelength carrier phase on L1 and L2 frequency
(1227 MHz). All data can be stored on the internal PCMCIA card. The receiver
permits uninterrupted use even when Anti-Spoofing (AS) is turned on. When AS is
on, the receiver automatically activates Ashtech’s patented Z-tracking mode that
mitigates the effects of AS. The performance when AS is on is the same as when AS
is off.
Memory Options
The amount of data the Z-Surveyor can retain depends upon the PCMCIA card
installed and the recording interval. You can verify the amount of memory by going
to the Memory Status (MEM:***%) menu under the S
YS
I
NFO
menu through the
front panel of the receiver. You can also verify the amount of memory by sending