1. Understanding what sh_gamit does

2. E-mail summary assesses over-all quality
Number of stations
Worst/best RMS scatter
postfit normalized RMS from solve
theoretically should be unity
typically around 0.2
(daily position scatter in accord with sigma)
Large adjustments to site positions
Any fatal messages
20-Nov-18
GAMIT/GLOBK Tutorial 4

3. Output files Cleaning summary: autcln.prefit.sum
autcln.post.sum -- Final postfit run
Solution files output by solve
qexpta.doy
human-readable
oexpta.doy
machine-readable
hexpta.yyddd
Full-precision for GLOBK suite
20-Nov-18
GAMIT/GLOBK Tutorial 4

4. Status files common to all GAMIT/GLOBK runs
File names, e.g, GAMIT.fatal
One long line per event
Three levels of severity
Status
Time of steps in processing
Warning
Items that might be in error
Fatal
Errors so large that the processing stopped
20-Nov-18
GAMIT/GLOBK Tutorial 4

5. Example GAMIT.status
STATUS :020119:1201: 6.0 ARC/aversn: Started ARC, \ Version 9.53 of 2001/01/03 10:30:00 (Linux)
STATUS :020119:1201: 6.0 ARC/arc: Integrating \
satellite 1 PRN 1
STATUS :020119:1201: 6.0 ARC/arc: Integrating \satellite 2 PRN 2
....…
To watch progress as it happens:
tail -f GAMIT.status
20-Nov-18
GAMIT/GLOBK Tutorial 4

6. Analyzing a solution: bias parameters
Number of biases fixed
Fixed bias have no sigmas in Q-file
608 B1L1 SMYC-TBLE \
609*B1L1 SMYC-TBLE \
The * means not fixed and sigma is given
Adjustments
parameters should not change much
20-Nov-18
GAMIT/GLOBK Tutorial 4

7. Analyzing a solution: adjustment sizes
Adjustments should not be too large
Convergence rate is 100 or 1000 to 1
Suppose an adjustment of 1 m in position
residual error could be 1-10 mm
solution needs to be iterated
Atmospheric delay variations
Magnitude of gradients
EOP adjustments
Some examples (shown externally)
20-Nov-18
GAMIT/GLOBK Tutorial 4

8. autcln output autcln.out.Z full output automatically compressed
use uncompress or use zcat to view
Lists actions taken by autcln
autcln.prefit.sum
autcln.post.sum
Summaries
Look at these
20-Nov-18
GAMIT/GLOBK Tutorial 4

9. autcln summary files Clock & range stats from range data
Repeated twice since solution is iterated
List of double difference bias flags
Number of bias flags added to jumps in double differences
If too many flags are added, then autcln removes the site/satellite combination completely. This can happen if a satellite burns. Rare if IGS orbits are used since satellite is removed from orbit files.
Bad site coordinates can cause many bias flags
20-Nov-18
GAMIT/GLOBK Tutorial 4

10. autcln summary file One-way post-fit residual statistics
Only in postfit autcln summary
Gives RMS in mm
by station and each satellite for a station
Normal values are 3-10 mm
>10 mm is not good
sky plots show residuals
cview views residual time series interactively
reads C-files
default is to delete these files during batch runs)
20-Nov-18
GAMIT/GLOBK Tutorial 4

11. Autcln summary file AMS -- Averaged RMS of residuals
statistics for 25-point averages of residuals
theoretical white noise
should be 5X smaller than for single-point value
typically, though
AMS is 2X smaller than single point RMS
due to correlations in phase residuals
ratio of RMS/AMS
values to close to 1 mean systematic residuals
20-Nov-18
GAMIT/GLOBK Tutorial 4

12. Autcln summary files NUM number of values used to compute RMS ATELV
Elevation angle-dependence of RMS
fit to data noise model of the form
variance = A^2+(B/sin(elev))^2
Sky-Plots
residuals v. elevation angle
show effects of multipath and antenna gain
20-Nov-18
GAMIT/GLOBK Tutorial 4

13. Autcln summary: data amounts
Data counts by site and satellite:
N(good)
N(deleted)
N(bias flags)
ignoring rising satellites
20-Nov-18
GAMIT/GLOBK Tutorial 4

14. Bias flag report Reports number of bias flags added for
GAP -- Due to gap in data
JMP -- Large jump on phase-range difference
ION -- Ionospheric delay jump
DDS -- Double difference scanning
WLS -- Wide lane scanning
DDC -- Double difference jump while cleaning data
20-Nov-18
GAMIT/GLOBK Tutorial 4