Yaesu FT5Dr Advance Manual page 27

"Positioning" refers to calculation of your current position from the satellite orbit
information and radio propagation time. At least 3 satellites need to be acquired for
successful positioning. If positioning fails, move away from buildings as far as possible
and stand in an area with open sky.
• About errors
The measurement environment may result in positioning errors of several hundred
meters. Under favorable conditions, positioning can be performed successfully using
only three satellites. However, under the following poor conditions, the positioning
accuracy can decrease or positioning can fail.
• Between tall buildings
• Narrow paths between buildings
• Indoors or near large buildings
• Under elevated roads or high voltage power lines
• Between trees such as in forests or woods
• Inside a tunnel or underground
• Through heat reflective glass
• Areas with strong magnetic fields
• When not in use for a long time
When using the GPS functions for the first time after purchase, or when it has been
unused in a while, a few minutes may be required to acquire the satellites. Also, if the
GPS function has been turned OFF for several hours, a few minutes may be required
to search for satellites.
About Positioning by GPS
27