Data Corrections
Although quality control procedures are routinely followed during the transformation of raw data to data products disseminated through this web site or by special request from the program office, subsequent corrections are sometimes necessary. The table below provides brief descriptions of some of these changes. The absence of information regarding a given site and time period is not an indication that no change has been made. Only the most serious errors which affect substantial amounts of data are given here. Changes can potentially impact multiple data products derived from the affected data. Users concerned about the effects of changes on their studies are encouraged to download data periodically to ensure the currency of their files. Users may also contact UVB personnel for further information.
Last Update: April 16, 2009
Location | Start Date | End Date | Changed Date | Problem Description |
|---|---|---|---|---|
| California, Davis(C) | 2001-01-01 | 2001-12-31 | 2002-08-01 | UV-MFRSR Irradiances corrected to compensate for faulty offset values. |
| Colorado, Longmont(R) | 2003-06-23 | 2003-09-28 | 2003-10-20 | UV-MFRSR Angular corrections changed from YES file to CUCF file. |
| Colorado, Longmont(R) | 2003-06-23 | 2003-10-01 | 2004-01-28 | UV-MFRSR Calibration error corrected. Problem began 2003-10-14. |
| New Mexico, Las Cruces (C) | 2000-11-14 | 2000-11-27 | 2004-04-09 | QC flags added for VIS-MFRSR band alignment problem; data unusable. |
| New Mexico, Las Cruces (C) | 2003-06-11 | 2004-05-04 | 2004-05-04 | Problem with VIS-MFRSR 665nm channel; data unusable during this time. |
| Arizona, Flagstaff(C) | 1997-04-24 | 1997-10-09 | 2004-05-26 | UV-MFRSR Irradiances re-calibrated using CSU board gains. |
| Alaska, Fairbanks(C) | 2004-05-21 | 2004-06-15 | 2004-06-16 | QC flags added for VIS-MFRSR band motion problem. |
| Hawaii, Waimea(C) | 2004-01-29 | 2004-03-31 | 2004-06-22 | UV-MFRSR Calibration error corrected. |
| New Mexico, Las Cruces (C) | 1997-05-01 | 1997-10-22 | 2004-07-01 | UV-MFRSR Calibration error corrected. |
| Maryland, Greenbelt(R) | 2004-03-26 | 2004-05-26 | 2004-09-10 | New UV-MFRSR angular corrections & calibration applied. |
| Texas, Panther Junction(C) | 2004-08-09 | 2004-10-27 | 2004-10-20 | QC flags added for sudden drop in VIS-MFRSR sensitivity. |
| All Locations | 2005-01-01 | 2005-01-25 | 2005-01-27 | Erythemal calibration problem for UVB-1 broadband data corrected. |
| All Locations | 2004-02-01 | 2004-02-10 | 2005-02-05 | Errant "bc2" QC flags pertaining to UVB-1 broadband data removed. |
| Colorado, Nunn(C) | 1999-11-10 | 1999-11-11 | 2005-02-07 | QC flags added for ground loop problem in UVB-1 broadband data. |
| Maine, Presque Isle(C) | 1998-12-11 | 1998-12-18 | 2005-02-08 | Data's timestep was off by 2 hours. |
| Oklahoma, Billings(C) | 2004-06-02 | 2005-02-17 | 2005-03-10 | QC flags added for sudden drop in VIS-MFRSR 610 & 665nm sensitivity. |
| California, Holtville(C) | 2004-07-01 | 2005-03-31 | 2005-03-31 | Problem with VIS-MFRSR 665nm channel, data unusable during this time, end of affected period is uncertain. |
| Maryland, Beltsville(C) | 2005-07-17 | 2005-08-10 | 2005-08-15 | QC flags added for VIS-MFRSR failure. |
| Michigan, Pellston(C) | 2004-07-14 | 2005-08-22 | 2005-08-22 | QC flags for sudden drop in VIS-MFRSR sensitivity added early each month for the previous month. |
| Ontario, Toronto(C) | 2005-11-01 | 2006-03-20 | 2006-03-20 | Faulty UV-MFRSR Angular corrections applied. Channel 368 was affected. |
| Colorado, Longmont(R) | 2005-11-10 | 2005-12-02 | 2006-03-27 | Angular corrections and calibration data changed to use correct serial number data. |
| Louisiana, Baton Rouge(C) | 2005-10-01 | 2006-03-31 | 2006-04-05 | UV-MFRSR Angular corrections changed to a newer file from CUCF |
| Louisiana, Baton Rouge(C) | 2006-03-21 | 2006-03-29 | 2006-04-05 | Diffuser Dirty quality control flag was added to the Vis-MFRSR and UV-MFRSR data. Wavelength channel data, PAR data and UVB-1 broadband data was impacted. |
| Illinois, Bondville(C) | 2006-03-07 | 2006-04-07 | 2006-04-07 | UV-MFRSR Angular corrections error corrected. |
| Florida, Homestead(C) | 2006-01-17 | 2006-10-12 | 2006-10-12 | UV-MFRSR Calibration error corrected. |
| New York, Geneva(C) | 2006-07-11 | 2006-10-12 | 2006-10-13 | Wrong calibration factors where applied. |
| Montana, Poplar(C) | 2006-11-09 | 2006-11-16 | 2006-11-16 | Broadband calibration factors not applied. |
| Oklahoma, Billings(C) | 2006-08-01 | 2006-12-07 | QC flags for channel failure for open, 415 and 940 added. Data should not be used. | |
| All Locations | 2001-01-01 | 2007-07-02 | 2007-07-02 | Significant improvement in most Calibrated Data after 2001 was implemented on July 2, 2007. Lamp-calibrated irradiance values for the 311, 317, 325, 332, 368 channels have increased, on average, 8.8%, 22.1%, 12.1%, 11.2%, and 4.0% respectively. The 300 and 305 channels are essentially unchanged as well as the Langley calibrated data. |
| All Locations | 2001-01-01 | 2007-12-11 | 2007-12-11 | As of December 11, 2007, it was found that the Langley calibrated irradiances were in error by about +/- 3.5%. The Langley calibrations are now corrected to properly account for earth-sun distance. Previous Langley Calibrations were about 3.5% too small in January and 3.5% too large in July. Since all irradiances are calibrated at the time of the user's request, any Langley calibrated data will now reflect the proper earth-sun distance factor regardless of the date and time of the measured data. |
| All Locations | 1994-01-01 | 2007-12-31 | 2008-01-21 | The daily vnaughts for our visible wavelength range have been regenerated using a simple linear regression technique. The previous method, Dr. Joseph Michalsky's Forgan technique has been discontinued. |
| Texas, Seguin(C) | 2006-08-01 | 2008-03-31 | 2008-04-30 | Wrong par calibration factor was applied. |
| North Carolina, Raleigh(C) | 2007-11-01 | 2008-03-31 | 2008-04-30 | Wrong Broadband calibration factor was applied. |
| Maryland, Queenstown(C) | 2006-09-17 | 2008-11-04 | QC flags for channel failure for 415, 500, and 665 added. Data should not be used. | |
| New York, Geneva(C) | 2008-06-11 | 2008-11-04 | QC flags for channel failure for 415, 500, 610 and 940 added. Data should not be used. | |
| Arizona,Flagstaff(C) | 2001-11-02 | 2008-11-21 | 2008-11-21 | The 311 channel was using a wrong gain factor in our calibration process. The errant gain factor used, increased the calibrated irradiance value by 1.6222. |
| Hawaii, Waimea(C) | 2001-01-22 | 2001-03-27 | 2008-11-26 | The 311 channel is saturated. Added the quality control flag to designate the saturation. Data for this channel should not be used. |
| New York, Geneva, NY02 | 2006-07-11 | 2006-09-01 | 2009-03-16 | Wrong serial number used. |
| Colorado, Steamboat Springs, CO12 | 2002-05-30 | 2003-03-10 | 2009-04-15 | UV-MFRSR Angular corrections error corrected. |
| Oklahoma, Billings, OK02 | 2003-04-11 | 2004-11-19 | 2009-04-15 | UV-MFRSR Angular corrections error corrected. |
| California, Holtville, CA22 | 2005-02-17 | 2009-04-15 | 2009-04-15 | UV-MFRSR Angular corrections error corrected. |
| Minnesota, Grand Rapids, MN02 | 2003-09-11 | 2004-07-20 | 2009-04-16 | UV-MFRSR Angular corrections error corrected. |
| Maine, Presque Isle, ME12 | 2004-09-15 | 2005-10-07 | 2009-04-16 | UV-MFRSR Angular corrections error corrected. |
| Vermont, Burlington, VT02 | 2004-10-20 | 2009-04-16 | 2009-04-16 | UV-MFRSR Angular corrections error corrected. |
| Saskatchewan, Regina, SK02 | 2005-09-14 | 2006-07-26 | 2009-04-16 | UV-MFRSR Angular corrections error corrected. |
| All Locations | 2006-01-01 | 2009-11-01 | 2009-11-01 | As of November 1, 2009, lamp and Langley calibrated irradiances received a correction of about +/- 1.5% (typical) to +/- 5.0% (maximum). The largest impact is on the early morning and late afternoon direct normal irradiance (low sun angles). The impact on daily sums is minimal. The magnitude of the correction is location dependent - for more information please contact the UVMRP staff. |