G-858BP Backpack Mag
Operators Manual
GPS Operation
The G-858BP is supplied with an integrated NovAtel Smart Antenna WAAS/EGNOS or Novatel
Smart V1 enabled GPS. This system operates well in most areas of the world although WAAS is not
available in all areas (see below). The Smart Antenna or Smart V1 and the G-858BP logging console are
preprogrammed at the factory for proper operation. No further interaction with the console interface is
required although the Smart V1 does require that the owner contact Omnistar for subscription to the
Differential Correction Serivce. See section 10 in this manual for more instructions. In the odd event that
the Smart Antenna or Smart V1 loses preprogramming, we provide a programming cable and instructions
on how to reprogram the GPS in Section 10 of this manual.
The G-858BP uses a metronome beat to help the survey operator keep a steady pace. Should the
quality of the GPS fix change, the tone of the Metronome will change to indicate poor GPS data. We will
be upgrading this manual in the near future with additional information on this feature.
What is WAAS? Basically, it is a system of satellites and ground stations that provide GPS signal
corrections, giving better position accuracy than standard GPS. On average the position accuracy is
increased up to factor of five times. A WAAS-capable receiver can give a position accuracy of better than
three meters 95 percent of the time. There are no service fees to use the WAAS service.
Currently, WAAS satellite coverage is only available in North America. There are no ground
reference stations in South America, so even though GPS users there can receive WAAS, the signal has not
been corrected and thus would not improve the accuracy of their unit. For some users in the U.S., the
position of the satellites over the equator makes it difficult to receive the signals when trees or mountains
obstruct the view of the horizon. WAAS signal reception is ideal for open land and marine applications.
WAAS provides extended coverage both inland and offshore compared to the land-based DGPS
(differential GPS) system. Another benefit of WAAS is that it does not require additional receiving
equipment, while DGPS does.
Other governments are developing similar satellite-based differential systems. In Asia, it's the
Japanese Multi-Functional Satellite Augmentation System (MSAS), while Europe has the Euro
Geostationary Navigation Overlay Service (EGNOS). Eventually, GPS users around the world will have
access to precise position data using these and other compatible systems.
The Smart V1 has a real-time differential correction service capability which can be accessed from
www.omnistar.com. This give approximately 0.5m accuracy over most of the world although very high and
very low latitudes are not covered. See more at Omnistar and in section 10 of this manual.
Self Test
Selecting SELF TEST from the Main Menu will display the following menu:
DIAGNOSTIC MENU
KEYPAD
SOUND
DISPLAY
REAL TIME CLOCK
MEMORY
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