C-Nav 2050, User Manual

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2050 User Guide
Global Positioning System
Selective availability ( S/A code) was disabled on 2
nd
May 2000 at 04:05 UTC . The United
States government has stated that present GPS users do so at their own risk. The US
Government may at any time end or change operation of these satellites without warning.
The U.S. Department of Commerce Limits
Requirements state that all exportable
GPS products contain performance limitations so that
they cannot be used to threaten the security of the United States.
Access to satellite measurements and navigation results will be limited from display and
recordable output when predetermined values of velocity and
altitude are exceeded. These
threshold values are far in excess of the normal and expected operational parameters of the
2050
GPS Sensor.
COCOM Limits
The U.S. Department of Commerce requires that all exportable GPS products contain
performance limitations so that they cannot be used in a manner that could threaten the
security of the United States. The following limitations are implemented on the C-Nav[2050]
GPS Receiver.
Immediate access to satellite measurements and navigation results is disabled when the
receiver’s velocity is computed to be greater than 1000 knots (515 meters per second), or its
altitude is computed to be above 18,000 meters. The receiver continuously resets until the
COCOM situation is cleared.
Use of this Document
This User Guide is intended to be used by someone familiar with the concepts of GPS and
satellite surveying equipment.
Note indicates additional information to make better use of the product
a
Indicates a caution, care, and/or safety situation
Warning indicates potentially harmful situations
iv