CSI Wireless Seres, Reference Manual

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Seres Reference Manual
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RTCM has various levels of detail, however the highest level is the message.
RTCM defines numerous messages that contain specific information. The
Seres antenna processes the C/A code and does not support more
advanced methods of differential positioning, such as real-time kinematic
(RTK) that uses different RTCM message types. Considering this fact, only
certain RTCM messages are important for use with the Seres:
•
Type 1 and Type 9 messages, both of which contain similar information.
These two messages contain pseudorange corrections and range rate
corrections to each GPS satellite.
•
The Type 2 message contains delta differential corrections that are used when
the remote receiver is using a different satellite navigation message than used
by the base station.
•
The Type 5 message contains GPS constellation health information used for
improving tracking performance of a GPS receiver
•
The Type 6 message contains null information, and is broadcast so that a
beacon receiver demodulating the data from the broadcast does not lose lock
when the beacon station has no new data to transmit.
Note - RTCM is a local area data standard. This means that when
positioning with correction input to the Seres from an external
source or outputting corrections from the Seres to another GPS
receiver, performance will degrade as a function of distance from
the base station. The additional degradation will depend on the
difference in observed orbit and ionospheric errors between the
reference station and the remote unit. A general rule of thumb
would be an additional 1 m error per 100 miles. This error is
often seen as a bias in positioning, resulting in a position offset.
The scatter or the receiver is likely to remain close to constant.
The RTCM SC-104 data output by the Seres is converted from the RTCM
SC-159 data broadcast by SBAS.
Appendix D - Resources contains the contact information should you wish
to purchase a copy of the RTCM SC-104 specification.