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NLC 2016-07-18/19

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: Royal Observatory Edinburgh, 55.9N 3.2W
          unattended compact camera with limited field of view
          A ~325-35, h ~0-40; images every 15 min
Date: 2016-07-18/19

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:30:05  X                                  patchy cloud
21:45:06  X                                  patchy cloud
22:00:07  X                                  patchy cloud
22:15:10  X                                  almost overcast
22:30:19  X                                  almost overcast
22:45:19  X                                  almost overcast
23:00:32  X                                  almost overcast
23:15:53  X                                  widespread cloud
23:30:48  X                                  widespread cloud
23:45:47  X                                  widespread cloud
00:00:47  X                                  widespread cloud
00:16:23  X                                  patchy cloud
00:30:47  X                                  cloud to h 10
00:45:46  X                                  patchy cloud
01:00:47  NLC?       3     8                 through cloud
01:15:53  X                                  patchy cloud
01:30:32  X                                  patchy cloud to h 20
01:45:32  NLC?       3    13                 through cirrus
02:00:19  II         2    20                 through cirrus
02:15:10  II,III     2    25                 through cirrus
02:30:03  II,III     1    40                 some cirrus below
02:45:05  II,III     1    40                 some cloud below
03:00:01  0                                  somc cloud to h 10
03:15:01  0                                  cloud to h 10 or 15

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

Name: Horst Meyerdierks
Country: Scotland
Location: Edinburgh
Date: 2016/07/18-19
Start: 01:00
End: 02:45
Forms: II,III
Max elevation: 40
Max brightness: 3
Comments: Some cloud.
http://www.chiandh.eu/nlccam/20160718-19.shtml

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       NLC: 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)
-------- ------ ----- ----- ----- -----  ----- -------------------
01:00:47 15.000  10.0 -12.8  -3.7   9.1  0-255 q4639.jpg m4639.jpg
01:45:32  8.000  20.6 -11.1  -2.7  18.0  0-255 q4657.jpg m4657.jpg
02:00:19  4.000  24.0 -10.3  -2.1  28.4  0-255 q4661.jpg m4661.jpg
02:15:10  2.000  27.4  -9.4  -1.5  61.0  0-255 q4664.jpg m4664.jpg
02:30:03  1.000  30.8  -8.4  -0.7 130.9  0-255 q4666.jpg m4666.jpg
02:45:05  0.500  34.1  -7.3   0.3 158.5  0-255 q4669.jpg m4669.jpg

exp: Exposure time in seconds (200 ISO, f/2.8).
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).