Start Date | Start Time | End Date | End Time | Data Quality Metric |
---|---|---|---|---|
01/01/2000 | 0000 | 12/31/2008 | 2359 | Suspect |
Subject: | NSA/AERI/C1 - Hatch status in datastream suspect |
DataStreams: | nsaaerich2C1.a1, nsaaerich1C1.b1, nsaaerich2C1.b1, nsaaerich1C1.a1 |
Description: | The AERI has an external hatch that covers the foreoptics in precipitating conditions to minimize the exposure of these foreoptics (and in particular the scene mirror) to rain. Physical limit switches are used to detect if the hatch is open or closed, and the hatch's status is determined by the hatch controller and included in the AERI datastream. During this period of time, the hatch was determined to be indicated as open too frequently. Analysis of several case studies suggested that the hatch was actually opening and closing properly but that its status was not being correctly reported by the hatch controller to the datastream. This is a problem because the hatch may be indicated as open in the datastream when in reality it was closed; this would result in biases and misinterpretation of the data. In late-2008, the AERI mentors were able to figure out the problem with the hatch controller and resolve this issue. An algorithm was written to determine the hatch status from the observed spectrum. This algorithm was applied to all AERI spectra at the NSA site from Jan 2000 to August 2010; monthly netCDF files with the update flags are available as a PI product. Details of the method, and monthly distributions of the hatch condition, are in a report that is included with the data. The report demonstrates that the seasonal distribution of hatch open/closed conditions is much more uniform year-to-year, and much more realistic based upon the known seasonal dependence of precipitation at the NSA site. The data are available at http://iop.archive.arm.gov/arm-iop/0pi-data/turner/ Please view the publication of Using a Neural Network to Determine the Hatch Status for detecting when the hatch is in error. |
Suggestions: | All users of the NSA C1 AERI datastream should use the newly determine hatch status flags in their analysis. |
Measurements: | nsaaerich1C1.a1: more
nsaaerich1C1.b1: more nsaaerich2C1.b1: more nsaaerich2C1.a1: more |