DQR ID | Subject | Data Streams Affected |
---|---|---|
D060221.1 | NIM/MPL/M1 - False Positive Cloud Base Height Values During Solar Noon | nimmplM1.00, nimmplM1.a1 |
D060419.1 | NIM/TSI/M1 - Reprocess: Data processing problem | nimtsicldmaskM1.a1, nimtsiskycoverM1.b1 |
D061024.1 | NIM/TSI/M1 - Shadowband glare | nimtsiskycoverM1.b1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
12/27/2005 | 0000 | 04/20/2006 | 1400 |
Subject: | NIM/MPL/M1 - False Positive Cloud Base Height Values During Solar Noon |
DataStreams: | nimmplM1.00, nimmplM1.a1 |
Description: | As the laser ages, the output reduces. This lowers the signal to noise ratio. The lower signal to noise ratio interferes with the cloud base height algorithm to correctly determine if a cloud is actually present. During solar noon the signal to noise ratio is the lowest. This condition results in many false positive values. The values start at a high altitude and progressively get lower as the sun gets to zenith. The trend reverses as the sun passes. The pattern in the data resembles a ?V? shape starting 2 hours before solar noon to 2 hour past. A low incident of false positive values exists from 20051227. However, the condition becomes prominent on 20060303 - 20060420. The cloud base calibration table was modified to compensate for the lower signal to noise levels. Note: If a cloud is actually present, the cloud base algorithm will determine the height and report correctly. The false positive values are only a concern during cloud free conditions. |
Measurements: | nimmplM1.a1:
nimmplM1.00:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/24/2005 | 0000 | 09/19/2006 | 1729 |
Subject: | NIM/TSI/M1 - Reprocess: Data processing problem |
DataStreams: | nimtsicldmaskM1.a1, nimtsiskycoverM1.b1 |
Description: | Due to the high aerosol conditions at Niamey, the TSI appeared to be beyond the limits of processing the color JPEG image into cloud fraction values. Several attempts to adjust the sky filter values used to process the images did not yielded the desired results. The processed images indicate an opaque sky cover, even in the absence of clouds. The problem was corrected by removing the neutral density filter from the lens and re-adjusting the sky filter values. The data can be reprocessed. |
Measurements: | nimtsicldmaskM1.a1:
nimtsiskycoverM1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/17/2006 | 1310 | 11/01/2006 | 0700 |
Subject: | NIM/TSI/M1 - Shadowband glare |
DataStreams: | nimtsiskycoverM1.b1 |
Description: | When the neutral density filter was removed from the lens, the reflection of the sun from the smooth shadowband strip became much brighter causing a glare in the image on clear days. To minimize this reflection, a rough surface (the "fuzzy" side of an adhesive velco strip) was placed along the length of the shadowband. |
Measurements: | nimtsiskycoverM1.b1:
|