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NTRIP is a generic, stateless protocol based on the Hypertext Transfer Protocol HTTP/1.1 and is enhanced for GNSS data streams. [1] The specification is standardized by the Radio Technical Commission for Maritime Services (RTCM). [2]
All satellites broadcast at the same two frequencies, 1.57542 GHz (L1 signal) and 1.2276 GHz (L2 signal). The satellite network uses a CDMA spread-spectrum technique [167]: 607 where the low-bitrate message data is encoded with a high-rate pseudo-random (PRN) sequence that is different for each satellite. The receiver must be aware of the PRN ...
GNSS systems that provide enhanced accuracy and integrity monitoring usable for civil navigation are classified as follows: [5] GNSS-1 is the first generation system and is the combination of existing satellite navigation systems (GPS and GLONASS), with Satellite Based Augmentation Systems (SBAS) or Ground Based Augmentation Systems (GBAS). [5]
A software GNSS receiver is a Global Navigation Satellite System (GNSS) receiver that has been designed and implemented using software-defined radio.. A GNSS receiver, in general, is an electronic device that receives and digitally processes the signals from a navigation satellite constellation in order to provide position, velocity and time (of the receiver).
Assisted GNSS (A-GNSS) is a GNSS augmentation system that often significantly improves the startup performance—i.e., time-to-first-fix (TTFF)—of a global navigation satellite system (GNSS). A-GNSS works by providing the necessary data to the device via a radio network instead of the slow satellite link, essentially "warming up" the receiver ...
The data link layer is concerned with local delivery of frames between nodes on the same level of the network. Data-link frames, as these protocol data units are called, do not cross the boundaries of a local area network. Inter-network routing and global addressing are higher-layer functions, allowing data-link protocols to focus on local ...
Precise positioning is increasingly used in the fields including robotics, autonomous navigation, agriculture, construction, and mining. [2]The major weaknesses of PPP, compared with conventional consumer GNSS methods, are that it takes more processing power, it requires an outside ephemeris correction stream, and it takes some time (up to tens of minutes) to converge to full accuracy.
The US Nationwide Differential GPS System (NDGPS) was an augmentation system for users on U.S. land and waterways. It was replaced by [dubious – discuss] NASA's Global Differential GPS (GDGPS) system, which supports a wide range of GNSS networks beyond GPS. The same GDGPS system underlies WAAS and A-GNSS implementation in the US. [11]