GPS Reviews Online
How to read GPS reviews
Online GPS reviews are meant to be a helpful tool to the bewildered consumer. All too often however, they are so full of complex terms and elaborate jargon that they only in confuse the situation further. The list below features some of the baffling terms that often appear in GPS reviews, as well as a short explanation on each.
- Acquisition: The process when a GPS receiver acquires and locks onto satellite signals.
- Anywhere fix: A fix made by a unit that has not received any data relating to approximate time or coordinates. Technically a 'false' fix.
- Bandwidth: The term used to describe a collection of frequencies that make up a band. Bandwidth is expressed in hertz which is the scientific measure for cycles per second. GPS units operate on two bandwidths - one has been set aside for commercial use, while the other is reserved for military operations.
- Channel: In relation to GPS receivers, a channel refers to the hardware, software and bandwidth used to lock on to the transmissions emitted by a single GPS satellite. Manufacturers try to make their products sound advanced by claiming that they have 12 channels, but in reality most GPS receivers have 12 channels.
- Differential GPS: An advanced method that was developed to reduce errors in position fixes by GPS receivers. Differential GPS makes use of carefully analyzed data from a well positioned station.
- EGNOS: The European Geostationary Navigation Overlay Service. A form of technology that is able to test the accuracy of GPS satellite emissions and relay error information to GPS receivers.
- ETA: estimated time of arrival.
- ETE: estimated time en route: The time it will take to reach a specific destination at a particular constant speed as calculated by a GPS system.
- Fix: The process whereby a GPS receiver is able to determine its own position on earth through the manipulation of distance and positional information that it receives from a set of GPS satellites.
- GPS time: The time frame to which GPS signals refer.
- Initialization: A GPS receiver initializes the first time it locks onto satellite transmissions.
- Integrity: The ability of a receiver to alert users when not to use a positional and navigational system. A GPS receiver needs to lock on to transmissions from four or more satellites in order to provide integrity.
- MOB: The man overboard facility that is feature in certain marine GPS monitors.
- PNF: Personal Navigator Files. Files stored in a GPS system that keep a record of personal traveling routes for future reference.
- Ranging code: A scheme of signals used to make distance calculations.
- Route: A collection of Waypoints that are stored in a GPS system and used for navigational purposes.
- Topographical map: a map that includes both horizontal distance (height above sea level) and vertical information (distance between two points). These kinds of maps are typically used on hiking and camping trips.
- Track: Recorded routes stored in a GPS memory.
- Two-dimensional mode: A GPS receiver that operates by locking onto only three satellites. This type of receiver can only supply a user with longitudinal and latitudinal positional information.
- Three-dimensional mode: A GPS receiver operating off four or more satellites. This type of receiver can supply longitudinal, latitudinal and altitudinal positional information.
- WAAS: An abbreviation often used in GPS reviews but hardly ever explained. WAAS refers to a Wide Area Augmentation System. This system is used in more advanced GPS receivers to enhance the accuracy of positional readings and make GPS available over a wider area.
- Waypoint: A position determined by longitudinal and latitudinal readings that can be stored in a GPS receiver and used to determine routes during navigation. Certain GPS monitors are able to store more waypoints than others.