APPENDIX B
Elevation Mask
Refers to the angle below which a satellite is considered unusable. It is used to prevent
the receiver from searching for satellites which are obscured by buildings or mountains.
Ephemeris
A set of parameters that describe the satellite orbit very accurately. It is used by the
receiver to compute the position of the satellite. This information is broadcast by the
satellites.
- F -
FRQ
Frequency.
- G -
GDOP
GDOP refers to the Geometric Dilution of Precision. It describes how much of an
uncertainty in range affects the uncertainty in position. The GDOP depends on where the
satellites are relative to the user.
A large GDOP means that a small error in range will translate into a large error in
position. GDOP has two components:
PDOP (Position Dilution of Precision).
TDOP (Time Dilution of Precision).
Geoid
Refers to the actual physical shape of the earth which is hard to describe mathematically
due to the irregularities of the local surface and the land-sea variations.
GMT
Greenwich Mean Time.
GMT Offset/Local Time Offset
An example of the difference between local time and GMT time is:
EST (Eastern Standard Time) minus GMT time is five hours.
B-4
ET6xxx ExacTime GPS TC & FG (Rev C)
Symmetricom Inc
Содержание ET6000
Страница 63: ...CHAPTER THREE This Page Intentionally Left Blank 3 28 ET6xxx ExacTime GPS TC FG Rev C Symmetricom Inc ...
Страница 105: ...CHAPTER FIVE This Page Intentionally Left Blank 5 14 ET6xxx ExacTime GPS TC FG Rev C Symmetricom Inc ...
Страница 121: ...APPENDIX B This Page Intentionally Left Blank B 12 ET6xxx ExacTime GPS TC FG Rev C Symmetricom Inc ...
Страница 136: ...OPTION DESCRIPTIONS ASSEMBLY 55116 Symmetricom Inc ET6 ExacTime GPS TC FG Rev C C 15 ...
Страница 141: ...APPENDIX C ASSEMBLY 100002 C 20 ET6xxx ExacTime GPS TC FG Rev C Symmetricom Inc ...
Страница 156: ...OPTION DESCRIPTIONS ASSEMBLY 55128 Symmetricom Inc ET6xxx ExacTime GPS TC FG Rev C C 35 ...
Страница 162: ...OPTION DESCRIPTIONS ASSEMBLY 55115 Symmetricom Inc ET6xxx ExacTime GPS TC FG Rev C C 41 ...
Страница 176: ...OPTION DESCRIPTIONS ASSEMBLY 55143 Symmetricom Inc ET6xxx ExacTime GPS TC FG Rev C C 55 ...
Страница 185: ...APPENDIX C ASSEMBLY 55155 ET6xxx ExacTime GPS TC FG Rev C Symmetricom Inc C 64 ...
Страница 202: ...OPTION DESCRIPTIONS ASSEMBLY 100001 Symmetricom Inc ET6xxx ExacTime GPS TC FG Rev C C 81 ...
Страница 203: ...APPENDIX C This Page Intentionally Left Blank ET6xxx ExacTime GPS TC FG Rev C Symmetricom Inc C 82 ...
Страница 205: ...APPENDIX D This Page Intentionally Left Blank A 2 ET6xxx ExacTime GPS TC FG Rev C Symmetricom Inc ...