chi and h site logo

NLC 2010-07-25/26

BAA report

The report to the BAA Aurora Section gives an overview of the night, which times were cloudy, free of NLC, or with sightings of NLC.

Name of observer: Horst Meyerdierks
Location: Stichill Eastfield, 55.7N 2.4W
          unattended dSLR with limited field of view A ~310-20, h ~0-40
          images every 15 min
Date: 2010-07-25/26

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:00  X                                  only top right clear
21:15  X                                  cloud to h ~20
21:30  X                                  cloud to h ~15
21:45  X                                  cloud to h ~15
22:00  X                                  cloud to h ~10
22:15  0                                  some cloud on left
22:30  0                                  cloud patches
22:45  0                                  cloud patches
23:00  0                                  cloud patches
23:15  0                                  cloud above ~15
23:30  0                                  cloud on left
23:45  0                                  cloud patches
00:00  0                                  widespread cloud patches
00:15  0                                  widespread cloud patches
00:30  0                                  widespread cloud patches
00:45  0                                  widespread cloud patches
01:00  0                                  widespread cloud patches
01:15  IV          1    5        ~0  ~15  widespread cloud patches
01:30  IV          1    7      <360  >15  through cloud
01:45  IV          1   >5                 through cloud
02:00  X                                  only partially clear
02:15  II          2   >8                 through cloud
02:30  X                                  almost overcast
02:45  X                                  overcast
03:00  X                                  overcast
03:15  X                                  overcast
03:30  X                                  almost overcast

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       NLC: other than or multiple of I-IV
       0: no NLC
       X: no decision possible (mist, cloud etc.)
brightness: 1: very weak
            2: clearly detected
            3: clearly visible
            4: very bright
            5: extremely bright

NLCnet report

The main periods of absence of NLC are reported to the NLC Observers' Home Page:

Name: Horst Meyerdierks
Country: Scotland
Location: Stichill
Date: 2010/07/25-26
Start: 22:15
End: 01:00
Comments: Cloud patches.

The main periods of positive sightings of NLC are reported to the NLC Observers' Home Page:

Name: Horst Meyerdierks
Country: Scotland
Location: Stichill
Date: 2010/07/25-26
Start: 01:15
End: 02:15
Forms: II,IV
Max elevation: 8
Max brightness: 2
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2010-07-25/26">Images</a>.

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       O: other than or multiple of I-IV
brightness: 1: very weak
            2: clearly detected
            3: clearly visible
            4: very bright
            5: extremely bright

Images

Listed below are the images with positive sightings of NLC. These have been processed merely to adjust the brightness for underexposure. For some, there may also be an unsharp-masked version of the image.

  UT    exp    A    hSun  h15   h85  stretch  image      (masked)
----- ------ ----- ----- ----- -----  ----- -------------------------
01:15 30.000  14.2 -13.8  -4.3   6.1  0-255 q32856.jpg m32856.jpg
01:30 30.000  17.8 -13.2  -3.9   7.6  0-255 q32862.jpg m32862.jpg
01:45 15.000  21.4 -12.5  -3.5   9.9  0-255 q32867.jpg m32867.jpg
02:15  8.000  28.4 -10.8  -2.4  21.9  0-255 q32877.jpg

exp: Exposure time in seconds (400 ISO, f/3.5).
A: Azimuth of the Sun (degrees).
hSun: Altitude of the Sun (degrees, negative below horizon).
h15: Max. altitude of sunlight at 15 km height (degrees).
h85: Max. altitude of sunlight at 85 km height (degrees).
stretch: Contrast stretch (0-255 means no stretch).