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iGage iG9 User Manual
locations in the middle of the North side of the open area are preferable because the southern sky
effectively opens up:
Longer Observations
OPUS-RS is especially vulnerable to bad sites. If you think a site may have problems, try to collect
over two hours of data so that you will have the option of using OPUS-Static. You can always trim
the 2-hour observation file and also submit it as a Rapid Static job in addition to the Static job.
A six-hour occupation may return great results at a site where 2-hour occupations fail. More-time in
adverse locations is always better.
#10 Mission Planning
With modern GNSS RTK receivers that track lots of satellite constellations and lots of signals, mission
planning is no longer required. A full GNSS receiver tracks so many satellites that there are no bad
times...
However, OPUS is GPS only and mission planning should be used to select better times to occupy
sketchy locations. Especially if you are using OPUS-RS.
Here is a typical GPS Only Mission Planning example:
Lower DOP is better than higher DOP. You can see that most of the day, DOP is excellent. Most
OPUS submissions will be successful. However, starting at 5:30 pm there are large DOP spikes.
At this location, on this day, any one-hour OPUS-RS occupation from 5:30 pm to 9:30 pm will
certainly
fail
. But a one-hour OPUS-RS occupation from 11:30 am to 12:30 pm (or most of the rest of
the day) will probably be
successful
.
