Just read my December issue of GPS World Magazine and they have a summary on all Constellations. I will summarize their summary.
GPS -?ÿ31 active satellites, 12 of which broadcast L5.
Glonass - 24 active satellites
Galileo - 16 active satellites, 4 additional were launched 12/12/2017
Beidou - 20 active satellites, 7 in typical orbits, 5 in geostationary orbits, 8 in inclined geosynchronous orbits
IRNSS, Indian Regional Navigation Satellite System - 3 in geostationary orbits, 4 in inclined geosynchronous orbits, broadcast L5 and S Band
SBAS - Space Based Augmentation Systems almost all geostationary orbits
EGNOS - European Geostationary Navigation Overlay Service - 2 broadcasting GPS & Galileo corrections
GAGAN - India - GPS Aided GEO Augmented Navigation - 3 satellites
GATBP - Australia - 1 satellite
MSAS - Japan - Multi-functional Satellite Augmentation System - 1 satellite
NMSAS - Nigerian Satellite Augmentation System - 1 satellite
QZSS - Japan - Quazi Zenith Satellite System?ÿ- 4 satellites that wander N-S from Equator such that 1 is always over Japan
SDCM - Russia - System for Differental Correlation & Monitoring - 3 satellites - GPS and Glonass corrections
WAAS - USA - Wide Area Augmentation System - 4 satellites
Of the 19 SBAS satellites 13 broadcast L1/L5?ÿ
Paul in PA
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On average we work with about 16 birds using only GPS and GLONASS but would like to work with Galileo as well, it is an option but comes at a cost.?ÿ
They upped the amplitude on the L5 signal, they're thinkung they can use this indoors ??
Anywhere from 14-21, depending on location, terrain, etc.?ÿ
Usually have 8-9 usable with another roughly same number in view but not usable.
Usually have 8-9 usable with another roughly same number in view but not usable.
?ÿ8 in view and useable?
Where are you working?
Paul in PA
Duane is working in woods of the lower Adirondacks on NY. But it does appear he may be using only NAVSTAR GPS SV's only, and not Glonass or any other others.?ÿ
I'm only a about 20 miles away from Duane and I see 12 to 18 SV's with GPS / Glonass enabled.
Nope, Glonass as well.?ÿ In view and useable two different things. Typically, half of what I'm seeing are not being used due to interference of one sort or another, or mask angle.?ÿ I know, one of the JAVAD guys captured my screen once and couldn't believe only 9 useable with 7 others not.?ÿ Tough GNSS country up here.
I have the advantage of working in open sky with construction work.
In Duane's situation, SV's just don't like those large Adirondack White Pine Trees where the property corners are.
Yes, to clarify, the software will not use signals from satellites that don't meet a certain threshold.?ÿ Separate process from determining best position from signals it does accept.?ÿ Spruce/fir also wreak havoc on GDOP as they can block anything but small window above. White pines tend to lose lower branches as they get big and not much undergrowth (shaded out), so sometimes get satellites through lower portions. Takes longer occupations than what folks think of as rtk as satellites move around. Not unusual to spend 1/2 hour on a point.
I understand that pines or any other needled evergreens are tough on GPS, they occur in limited areas around here. I see two problems with needles, they are dense for their small size with high moisture content but also their length is close to GPS wavelengths and can readily be found in di-pole antenna type arrays. Similar problem if you are near to a chain link fence.
By the way has anyone used a Javad setup with the quad antenna array? I could see that giving 4 solutions with none having the exact same satellites.
Paul in PA
