Important Notes

1. All the plotted data and images are just for browsing purpose and 
   are not fully calibrated.  Please do not use the data at any 
   presentations and publications without contacting the Principal 
   Investigators, K. Shiokawa (shiokawa at

2. Digital data are available on request.  Please contact the Principal 
   Investigator to copy the data.  The Principal Investigator
   may limit the use of the data in order to avoid possible confliction of 
   the scientific directions of the users.   

3. The all-sky image data at Rikubetsu (camera 3 after October, 1998) is 
   upside down (upward is toward the south) for October 20, 1998 - March 31,
   1999.  Please see figure captions.  

4. For the SATI data, the values of temperature may be corrected in the 
   future by using new calibration data sets.  Please also see the background 
   level in the plots.  High background means cloudy sky during which the 
   temperature and intensity data become meaningless.  

5. Please refer  Shiokawa et al. [1999] for details of the instrumentation.  

**************** some additional local notes *******

1. Camera A (10) at Paratunka was stopped for March 5-11, 2008, 
   due to condensation in the lens system after severe cyclone 
   on February 28, 2008.  The lens was cleaned on August 16-17, 2008. 

2. The CCD temperature of FP01 at Tromso raised from -80C (normal) 
   to ~-65C at Feb.16-Mar.11, 2010 due to water flow degradation.
   So the 630-nm temperature data may be affected. 

3. The FPI04 at Darwin has scanning problem.  The sky scanner does 
   not move for May 21-July 7, 2011, due to missing the position 

4. The Camera #11 (Camera B) at Magadan has a problem of A/D converter 
   of CCD since early 2014.  We make fast-scan measurements since April 2015. 
   The sensitivity becomes ~1/16.5 from slow scan to fast scan, and 
   the satulation level becomes from 65535 counts to 4096 counts.  

5. The Camera #10 (camera A) at Paratunka was repaired due to CCD cooler
   trouble and restarted the observation from 16 June 2015. 

6. In Dec 25, 2017, we found a problem on the timing recorded on the 
   filename of the OMTI all-sky imagers for PTK, MGD, ERK, KAP, NYR, 
   GAK, IST, and HUS.  The time in the filename can be incorrect for 
   some data.  Details are shown in this file.  
   This problem has already been fixed for most of the stations by 
   Dec. 30, 2017.  When you use the 2017 data of these imagers, please 
   be careful on the timing.   Please feel free to contact us if you 
   have any questions on the timing delay of each station.  

7. From December 16, 2015 to March 17, 2018, the sky-scan direction of the 
   Fabry-Perot interferometer at Darwin (FP04) is 7.5 degree shifted from 
   north-south (N-S) and east-west (E-W) to NNE-SSW and ESE-WNW.   
   This is due to the wrong setting of home position of the azimuth-scan 
   motor of the FPI skyscanner for 7.5degree.  

8. On April 19, 2018, we noticed that the router/IP setup of the FPI 
   PC was incorrect, causing the NTP automatic time correction was not 
   working.  The time difference from the correct time was 289.567s 
   delayed from the correct time on April 19, 2018. 

9. For Istok, GPS synchronization seems to be failed.  It was found on 
   March 5, 2019.  The PC clock of the imager is ~1 minute different from 
   correct time.  This error was corrected at 06 UT on March 5, 2019.  
   This error may be caused at the power failure on September 20, 2018.

10. Tilting photometer No.1 at Shigaraki has a clock error due to a 
    network trouble on April 8, 2021. The clock was 86287.828 sec 
    behind the true time.  The error seems to occur when the network 
    trouble happened before April 8, 2021, probably from March 31, 2021. 

11. FP04 at Darwin clock is 62sec ahead of correct time on April 19, 2021 
    due to wrong NTP server since March 9, 2021. 

12. CamG at Kapuskasing clock was 926.718sec ahead of correct time on 
    August 25, 2023, 08:10 UT.  It seems that the NTP server of the PC 
    did not work for a while, because the software (Sakura Watch) was 
    deleted by some reason.  We re-installed the Sakura Watch.

13. On Feb.3, 2024, we found a bug in the code to calculate fit error 
    of the wind velocity of Fabry-Perot interferoeters (FPIs). The fit 
    error can be systematically underestimated due to the bug.  This bug 
    does not affect the output wind velocity and temperatures.