Issue #5 - High Velocity ksr data - 201110
DDWG Mailing list link:
http://lists.le.ac.uk/pipermail/darn-ddwg/2014-August/000112.html
It came to our attention lately that a year or so ago, Simon Shepherd identified a period of bad data from the King Salmon radar in October 2010. The velocity recorded in the files in the attached high_vel_ksr.txt file are way high. It was confirmed (I'm fairly certain) with Jef Spaleta that something was not set correctly during a site visit to repair the radar which resulted in the high velocity values.
The high velocity values can be noticed in the attached RTI plot as well as the map potential plot. The map-level data was how Simon originally found this error.
Jef notes problem that created this error as:
The issue was a frequency offset on LO providing the reference clock. PTS's front panel dial for Hz was not firmly in the zero position (even though it appeared to be set to zero on visual inspection), so digital electronics LO was off by +1 Hz from the expected value. If memory serves it was the reference LO for the DDS card. Never figured out a way to reprocess rawacf files for the impacted period.
Kevin Krieger noted that these files were removed from the regular archives and blacklisted by 19:03 utc on 20140808. Re'syncing with the USask data mirror will show these files are missing (if you have deleted them from your archives as well).
Action Items
□ Remove the listed files as well as the subsequent processed files (fitacf) that match the listed filenames.
□ Reprocess any subsequent data products such as grid and map (with the fitacf files removed as well).
Supplementary Materials
high_vel_ksr.txt
20111020.ksr_bad_velocity.jpg
map_pot_20111020.2104.jpg
http://lists.le.ac.uk/pipermail/darn-ddwg/2014-August/000112.html
It came to our attention lately that a year or so ago, Simon Shepherd identified a period of bad data from the King Salmon radar in October 2010. The velocity recorded in the files in the attached high_vel_ksr.txt file are way high. It was confirmed (I'm fairly certain) with Jef Spaleta that something was not set correctly during a site visit to repair the radar which resulted in the high velocity values.
The high velocity values can be noticed in the attached RTI plot as well as the map potential plot. The map-level data was how Simon originally found this error.
Jef notes problem that created this error as:
The issue was a frequency offset on LO providing the reference clock. PTS's front panel dial for Hz was not firmly in the zero position (even though it appeared to be set to zero on visual inspection), so digital electronics LO was off by +1 Hz from the expected value. If memory serves it was the reference LO for the DDS card. Never figured out a way to reprocess rawacf files for the impacted period.
Kevin Krieger noted that these files were removed from the regular archives and blacklisted by 19:03 utc on 20140808. Re'syncing with the USask data mirror will show these files are missing (if you have deleted them from your archives as well).
Action Items
□ Remove the listed files as well as the subsequent processed files (fitacf) that match the listed filenames.
□ Reprocess any subsequent data products such as grid and map (with the fitacf files removed as well).
Supplementary Materials
high_vel_ksr.txt
20111020.ksr_bad_velocity.jpg
map_pot_20111020.2104.jpg
