tremors834
Adventurer
Anyone here carry a map and compass with them in addition to a GPS while Overlanding, Exploring, Hiking or Camping? I started using a GPS back in the late 90's when "selective availability" was still turned on. There used to be a concensus that one should not use a GPS if one can not use a map and compass. If your relying on your GPS and it stops working, at least you have a map and compass to get you where your going.
Any old timers here ever rely on a map and compass for overlanding before GPS was ever availible?
Following copy and pasted from the GPS Wiki explaining SA-
GPS includes a (currently disabled) feature called Selective Availability (SA) that adds intentional, time varying errors of up to 100 meters (328 ft) to the publicly available navigation signals. This was intended to deny an enemy the use of civilian GPS receivers for precision weapon guidance.
Before it was turned off on May 1, 2000, typical SA errors were about 50 m (164 ft) horizontally and about 100 m (328 ft) vertically.[62] Because SA affects every GPS receiver in a given area almost equally, a fixed station with an accurately known position can measure the SA error values and transmit them to the local GPS receivers so they may correct their position fixes. This is called Differential GPS or DGPS. DGPS also corrects for several other important sources of GPS errors, particularly ionospheric delay, so it continues to be widely used even though SA has been turned off. The ineffectiveness of SA in the face of widely available DGPS was a common argument for turning off SA, and this was finally done by order of President Clinton in 2000.
Any old timers here ever rely on a map and compass for overlanding before GPS was ever availible?
Following copy and pasted from the GPS Wiki explaining SA-
GPS includes a (currently disabled) feature called Selective Availability (SA) that adds intentional, time varying errors of up to 100 meters (328 ft) to the publicly available navigation signals. This was intended to deny an enemy the use of civilian GPS receivers for precision weapon guidance.
Before it was turned off on May 1, 2000, typical SA errors were about 50 m (164 ft) horizontally and about 100 m (328 ft) vertically.[62] Because SA affects every GPS receiver in a given area almost equally, a fixed station with an accurately known position can measure the SA error values and transmit them to the local GPS receivers so they may correct their position fixes. This is called Differential GPS or DGPS. DGPS also corrects for several other important sources of GPS errors, particularly ionospheric delay, so it continues to be widely used even though SA has been turned off. The ineffectiveness of SA in the face of widely available DGPS was a common argument for turning off SA, and this was finally done by order of President Clinton in 2000.
