“G” is for Ground Zero or “GZ”
Who? Anyone who is a Geocacher, interested in becoming one, or even a muggle friend or family member
What? Weekly RGV Geocaching Breakfast Meet & Greet *NOTE* purchase of food items is always optional however, fun and fellowship is a given.
Where? Country Omelette, 3420 N. 10th St., McAllen, TX 78501
When? Thursday, December 29, 2022 at 9:00 a.m. – 10:30 a.m.
Why? Share stories, tips & tricks of the game, assist with solving mystery/puzzle caches and share/trade trackables.
This season each event is part of an alpha series of titles highlighting a term used in Geocaching.
Today’s event is very near and dear to all Geocachers. It’s Ground Zero or "GZ"
Ground Zero (GZ)
The point where your GPS device shows that you have reached the geocache location. At ground zero, you are zero feet (or zero meters) away from your destination.
Your GPS unit’s GZ may be different than the Cache owner’s GZ and your buddy's smartphone GZ…
Why is this???
First, the government’s accuracy commitments do not apply to GPS devices, but rather to the signals transmitted in space. For example, the government commits to broadcasting the GPS signal in space with a daily global average user range error (URE) of ≤2.0 m (6.6 ft.), with 95% probability, across all healthy satellites in constellation slots.
Secondly, GPS satellites broadcast their signals in space with a certain accuracy, but what you receive depends on additional factors, including satellite geometry, signal blockage, atmospheric conditions, and receiver design features/quality.
For example, GPS-enabled smartphones are typically accurate to within a 4.9 m (16 ft.) radius under open sky. However, their accuracy worsens near buildings, bridges, and trees, weather conditions AND battery life.
Have you ever been Geocaching and your GPS kept changing your distance from GZ while you were standing perfectly still? Yep, that's URE and something's interferring with your reception.
GPS/Satellite Accuracy info and image are from: GPS.gov