GLOBAL POSITIONING SYSTEM (GPS)
NMEA 0183 - NMEA is a standard protocol, use by GPS receivers to transmit data. NMEA output is EIA-422A but for most purposes you can consider it RS-232 compatible. Use 4800 bps, 8 data bits, no parity and one stop bit ( 8N1 ). NMEA 0183 sentences are all ASCII. Each sentence begins with a dollarsign ($) and ends with a carriage return linefeed (<CR><LF>). Data is comma delimited. All commas must be included as they act as markers. Some GPS do not send some of the fields. A checksum is optionally added (in a few cases it is manatory). Following the $ is the address field aaccc. aa is the device id. GP is used to identify GPS data. Transmission of the device ID is usually optional. ccc is the sentence formatter, otherwise known as the sentence name.
Applanix Integrated inertial/GPS products
NovAtel Inc. markets and supports a broad range of products which determine precise geographic locations using the Global Positioning System ("GPS"). NovAtel's advanced GPS technology provides accuracy to the sub-centimeter level while showing a high degree of integrity in dynamic environments.