Geocaching Glossary of Terms.

Cache:

Pronounced "cash" - In geocaching it is a hidden container filled with a log book and pencil/pen, and possibly prizes. Caches were often used by explorers, miners, etc. to hide foodstuffs and other items for emergency purposes. People still hide caches of supplies today for similar reasons.

Geocaching comes from the terms "geo" and "cache" to explain the sport. Some caches have cash in them, but there is no pun intended.

Datum:

A datum is something used as a basis for calculating and measuring. In the case of GPS, datums are different calculations for determining longitude and latitude for a given location.

Currently, Geocaching uses the WGS84 datum for all caches. Many maps still use NAD27, which can cause confusion if your GPS unit is set to NAD27. Always check your GPS to ensure that WGS84 is the datum before entering a cache coordinate into your unit.

GPS:

GPS stands for Global Positioning System. It is a system of satellites that work with a GPS receiver to determine your location on the planet.

Geocaching uses GPS to help hide and seek caches on the planet.

Hitchhiker:

A hitchhiker is an item that is placed in a cache, and has instructions to travel to other caches. Sometimes they have logbooks attached so you can log their travels. A Travel Bug is an example of a hitchhiker.

Letterbox(ing):

Letterboxing is similar to Geocaching, but you use a series of clues to find a container. Once you find the container (or letterbox), you take a carved stamp from the box and stamp your personal logbook. You then take your carved stamp and stamp the letterbox's log book. See Letterboxing North America for more info.

NAD27:

Stands for North American Datum 1927. The precursor to WGS84. Many maps still use the NAD27 datum, so always check before using a GPS unit with a map.

Spoiler:

A spoiler is information that can give details away and ruin the experience of something. For example, telling someone the end of a movie before they see it. In geocaching, a spoiler gives away details of a cache location and can ruin the experience of the hunt.

Travel Bug:

A Travel Bug is a hitchiker.

UBBCode™:

UBBCode™ tags allow you to add formatting (bold, italics) and other information (emails, URLs) to your messages without learning HTML !

Virtual (cache):

Adapted from "Virtual Reality," virtual means "nothing there." So a virtual cache means there is no cache container. It's the location that is the cache itself. Nothing is normally traded, except photos and experiences.

WAAS:

WAAS stands for Wide Area Augmentation System.

Waypoint:

Waypoints are named coordinates representing points on the surface of the Earth.

Geocaching uses a suggested waypoint for a cache, created automatically when a cache has been created. Because most GPS units have restricted names to 6 characters or less, we generate a waypoint name based on the ID of the cache. It is optional, but makes it easier to locate a cache on the geocaching web site.

WGS84:

The most current geodetic datum used for GPS is the World Geodetic System of 1984 (WGS84). The significance of WGS84 comes about because GPS receivers rely on WGS84.

Geocaching uses the WGS84 datum by default. We also use the format HDDD MM.MM, which is a standard for GPS receivers (like the eTrex).

HDD means Hemisphere and degrees. MM.MM are minutes in decimal format.

It is critical that the format is correct, otherwise cachers will be unable to find your cache !

General Satellite Navigation Abbreviations.

A-S Anti-spoofing
C/A-code coarse/acquisition-code
CEP circular error probable
DGPS differential GPS
DOP dilution of precision
ECEF Earth-centered-Earth-fixed
FOM figure of merit
Galileo European Global Navigation Satellite System under development
GDOP geometric dilution of precision
GLONASS Global Navigation satellite system
GMT Greenwich Mean Time
GPS Global Positioning System
HDOP horizontal dilution of precision
HOW hand over word
INS Inertial Navigation System
L1 GPS primary frequency, 1575.42 MHz
L2 GPS secondary frequency, 1227.6 MHz
MSL mean sea level
MTBF mean time between failure
NMEA National Marine Electronics Association
P-code precise code
PDOP position dilution of precision
PPM parts per million
PPS Precise Positioning Service
PRN pseudo random noise
RF radio frequency
RINEX Receiver Independent Exchange Format
RMS root mean square
RSS root sum square
RTCA Radio Technical Commission for Aeronautics
RTCM Ratio Technical Commission for Maritime Services
RTK Real-Time Kinematic
SA Selective Availability
SEP spherical error probable
SPS Standard Positioning Service
TAI International Atomic Time
TDOP time dilution of precision
TTFF time to first fix
UT Universal Time
UTC Universal Time Coordinated
VDOP vertical dilution of precision
WGS84 World Geodetic System 1984
1 PPS 1 pulse per second

Links to other interesting Geocaching areas on the Internet:

Outdoors resources - directory of Outdoors related websites.