ashtech Z-Xtreme Quick Start Manual

Ashtech Z-Xtreme
Static Field Data Collection – Receiver Operation
GPS survey work can be accomplished through the use of conventional static procedures. Static
surveying is accomplished by collecting GPS data at a minimum of two locations simultaneously,
one at a known control station (Base Station) and the other occupying either known or unknown
sites, (Rover Stations). Static surveying may be performed simultaneously with as many receivers
as are available and usually last for a predetermined amount of time, (Session).
Scheduling the static surveys during abundant satellite coverage and good geometry is very
important to ensure the best possible accuracy for short collection periods. Plan to track at least
six healthy satellites as conditions may arise where the required minimum of five satellites
tracked by both receivers may be hindered by obstructions.
Tracking time for static surveying will be at 15-second recording intervals using an elevation
mask angle of 10-degrees. Each control point and new station will be occupied at least twice to
provide redundancy and a method to perform data comparisons unless checks are determined
between known control and conventional occupation of the new stations performs these checks.
Data files will be generated in the receivers occupying each site. Typically they will be
designated:
*AAAASYR.xxx
Where: * = Type of Data File, ( B, E, S-Files).
AAAA = 4-character Alpha-Numeric Site ID; S = Session ID; YR = Last 2-digits of Year
.xxx = Julian Day ( Day of Year).
Equipment Setup at All Stations:
GPS Antenna:
Plumb tripod over existing control or new station utilizing fixed height pole or optical tribrach.
Attach antenna cable to the GPS antenna and place the GPS antenna on the fixed height pole or
tribrach assembly. Align the North arrow on the GPS antenna to North and re-check the plumb
and set-up over the station. Measure the Slant Height to TGP, (Top of Ground Plane), at the
top, inside notch, of the brass antenna plate.
When using the Ashtech Geodetic-IV, L1/L2 antenna (p/n 701975-01) and the fixed height pole,
the nominal HI = 2.000m. The mechanical offset between the ARP (Antenna Reference Point ) to
TGP (Top of Ground Plane) = 0.043m. Note the Mechanical Offset and Electrical Phase Center
Offset labels on the underside of the GPS Antenna.
Check with the Field Coordinator for the GPS project, the preferred "Height Entered in
Receiver" value method. In most cases, 2.000m would be the "Height Entered in Receiver"
value, along with noting the documented GPS Antenna: Manufacturer and Model information.
Ashtech Geodetic-IV, p/n 701975-01 (-GP); No Ground Plane.
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