iG5 User Manual
62
Obstructions to the North not important in North
America
Note: OPUS will process observations down to
10
° elevation so you should set your receiver to start
tracking a few degrees below 10°, or just allow it to track
all the way to the horizon (0 degrees Elevation Mask.)
Attributes of a great GPS location for collection OPUS ready
occupations:
•
No overhead power lines
•
No trees: leaves on or leaves off
•
No power poles (wood or metal)
•
No radar or radio paths that cross over the top of
the receiver
•
No chain link fences nearby
•
Locations under busy landing paths are undesirable
•
No large ‘GPS reflective’ surfaces
(metal roofs)
nearby: avoid multipath
•
Receiver facing correct direction: usually MMI
(Man-Machine-Interface AKA the push buttons),
antenna connector or North fiduciary pointing to
the North.
•
Receiver mounted very securely on well braced,
fixed-height tripod
