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[McIDAS #JBA-785900]: Research Question

Hi Rod,

re:
> I am referring to this email.
> 
> My understanding is that I thought you didnt
> agree with with the google latitude and longitude and location of
> Hackleburg, AL to do the GVARINFO.

A couple of comments about this statement:

1) I just reread your original email and nowhere in that email
   did you mention anything about getting a latitude and longitude
   for Hackleburg, AL from Google Maps.  For that matter, you did
   not mention Hackleburg, AL at all in that email.

2) what you asked in your original email was:

"Ok could I use the SCAN Time displayed here see bold or do I have to use
the time displayed froom (GVAR_PFX5.FOR) SPS time: year?"

   My question was and still is:

   - use the time for what?

     What exactly do you want to use the time be used for?

In trying to guess what you wanting to use the time for, I
explained that for McIDAS commands like IMGLIST and IMGDISP,
the time specified in the TIME= keyword is the nominal time
of the image, not the time of a particular scan line.

> address@hidden> wrote:
> 
> > Hi Rod,
> >
> > re:
> > > Ok could I use the SCAN Time displayed here see bold or do I have to use
> > > the time displayed froom  (GVAR_PFX5.FOR)    SPS time: year?
> >
> > I think you are asking if you should pay attention to the 'Scan Time'
> > listed
> > from 'IMGPROBE MODE=N' or the time listed for the line by 'GVARINFO. Am I
> > interpreting your question correctly?
> >
> > I just did the following:
> >
> > - displayed the image using IMGDISP
> > - moved my mouse cursor over a point in the image
> > - ran 'IMGPROBE MODE=N'
> > - used the "File Line/Element' line listed by the IMGPROBE invocation as
> > the
> >   second positional parameter in a GVARINFO invocation
> >
> > The time 'Scan Time' listed by the IMGPROBE invocation was
> > the same as that listed by GVARINFO.  Here is the output that I
> > got from both:
> >
> > IMGPROBE MODE=N
> >
> >      Image Name           Day      Nominal Time   Scan Time    Band
> >   ----------------      -------    ------------   ---------    ----
> >   LOC/AREAS.2000      27 Apr 11117   20:25:00      20:27:46       4
> >
> >                         File     Nominal  Image     RAW         RAD
> >   TEMP        BRIT
> >        Lat/Lon      Line/Element  Line/Element                   *
> >   K
> >  35:21:45 / 88:03:24   369/ 1030    4529/13381           3296      16.700
> >      211.30         207
> >  *   milliwatts/meter**2/steradian/(cm-1)
> >
> > IMGPROBE: Done
> >
> > GVARINFO 2000 369
> >
> > (GVARINFO.PGM) *Starting execution on     2013051 (Wednesday February 20,
> > 2013)  at  152835 (HHMMSS) UTC
> > (GVARINFO.PGM)  Input program command line (in 80-byte segments):
> >
> >     GVARINFO 2000 369
> >
> >
> > (GVARINFO.PGM) Input area (IAREA) =        2000, input line # (LLI) =
> >     369, input calibration changes variable (CCI) =  369
> >    (GVAR_PFX6.FOR) This computer is a Little endian system.
> >    (GVAR_PFX6.FOR) Areafile #        2000 contains GOES-          13 data
> > (IMSAT=          13).
> >    (GVAR_PFX6.FOR) Areafile #        2000 is native to this computer
> > (ISAFMT(IAREA)=           0).
> >
> >    (GVAR_PFX6.FOR) Areafile #        2000 internal structure:
> >
> >    (GVAR_PFX6.FOR) 1.) AREAFILE DIRECTORY        =         256 bytes (=
> > hex         100)
> >    (GVAR_PFX6.FOR) 2.) NAVIGATION   block        =        2560 bytes (=
> > hex         A00)
> >    (GVAR_PFX6.FOR) 3.) CALIBRATION  block        =         512 bytes (=
> > hex         200)
> >    (GVAR_PFX6.FOR) 4.) SUPPLEMENTAL block        =           0 bytes (=
> > hex           0)
> >    (GVAR_PFX6.FOR) 5.) DATA         block begins with (0-based) byte #
> >    3328 (= hex         D00)
> >    (GVAR_PFX6.FOR) 6.) COMMENT      block contains           2 card(s) (=
> >         160 bytes)
> >
> >    (GVAR_PFX6.FOR) (NOTE: areafile line prefixes can contain: validity
> > code, documentation, calibration & a band list.)
> >    (GVAR_PFX6.FOR) Total length of line prefix (bytes)                   :
> >         232
> >    (GVAR_PFX6.FOR)    Total length of line prefix (4-byte words)         :
> >          58
> >    (GVAR_PFX6.FOR) Contents of areafile VALIDITY CODE (directory word
> > 36)(decimal & hex):   117202500,     6FC5E44
> >    (GVAR_PFX6.FOR) Length of line prefix DOCUMENTATION                   :
> >         228 bytes
> >    (GVAR_PFX6.FOR) Length of line prefix CALIBRATION                     :
> >           0 bytes
> >    (GVAR_PFX6.FOR) Length of line prefix BAND LIST                       :
> >           0 bytes
> >
> >    (GVAR_PFX6.FOR) GVAR line         369 prefix contents (bytes 1-
> > 232, in hexadecimal (= 2 hex values per byte)):
> >    (GVAR_PFX6.FOR)      (Display the data in groups of 4 bytes (8 hex
> > digits), 40 bytes per line.)
> >
> > 445EFC06 00000A81 00002011 11720274 6265020A 19220004 01020100 01D0BBA4
> > 00002011 11720275
> > 02040000 00001DDB 000D0001 00000006 00040000 00B9000A 03810002 004E0002
> > 005E0000 00000000
> > 0D010A81 00000000 00000000 00000000 00000000 00002011 11720274 62652011
> > 11720271 67382011
> > 11720271 71282011 11720271 61482011 11720271 65382011 11720251 8765FFFF
> > FFFFFFFF FFFF2011
> > 11720274 05232011 11720091 29052011 11720093 38262011 11720082 79562011
> > 11720151 04772011
> > 11720270 45771995 33412000 00002007 34815143 60002011 11715452 00710000
> >
> >    (GVAR_PFX6.FOR) GOES Imager information (from line prefix data) --
> >    (GVAR_PFX6.FOR)    (See  "GVAR Imager Data Block"  within the McIDAS
> > Programmers Manual
> >    (GVAR_PFX6.FOR)     (http://www.ssec.wisc.edu/mcidas/doc/prog_man.html)
> > for details on the
> >    (GVAR_PFX6.FOR)     structure of line prefixes within McIDAS GOES
> > Imager areafiles.)
> >
> >    (GVAR_PFX6.FOR) GOES Imager validity code (hex):     6FC5E44
> >    (GVAR_PFX6.FOR) ISSCAN_BYTE1 (pfx byte#           7), ISSCAN_BYTE2 (pfx
> > byte#           8) (decimal    ) =          10,         129
> >    (GVAR_PFX6.FOR) ISSCAN_BYTE1 (pfx byte#           7), ISSCAN_BYTE2 (pfx
> > byte#           8) (hexadecimal) =           A,          81
> >    (GVAR_PFX6.FOR) ISSCAN_BYTE3 (pfx byte#           9), ISSCAN_BYTE4 (pfx
> > byte#          10) (decimal    ) =           0,           0
> >    (GVAR_PFX6.FOR) ISSCAN_BYTE3 (pfx byte#           9), ISSCAN_BYTE4 (pfx
> > byte#          10) (hexadecimal) =           0,           0
> >    (GVAR_PFX6.FOR) ISSCAN (=ISSCAN_BYTE1, 2, 3 & 4), in binary =
> > 00001010100000010000000000000000
> >
> >    (GVAR_PFX6.FOR) (bit 0 of ISSCAN) indicates: no frame start
> >    (GVAR_PFX6.FOR) (bit 1) no frame end
> >    (GVAR_PFX6.FOR) (bit 2) no frame break
> >    (GVAR_PFX6.FOR) (bit 3) no pixel(s) lost
> >    (GVAR_PFX6.FOR) (bit 4) priority 1 frame data
> >    (GVAR_PFX6.FOR) (bit 5) not priority 2 frame data
> >    (GVAR_PFX6.FOR) (bit 6) East to West scan (IWEST_TO_EAST_FLAG =
> >   2)
> >    (GVAR_PFX6.FOR) (bit 7) North to South frame
> >    (GVAR_PFX6.FOR) (bit 8) IMC active
> >    (GVAR_PFX6.FOR) (bit 16) yaw flip processing NOT enabled (satellite is
> > NOT flipped)
> >
> >    (GVAR_PFX6.FOR) Block-0 time: year        2011 day of year         117
> > hh:mm:ss           20:          27:          46 msec         265
> >    (GVAR_PFX6.FOR)    (The above date/time information comes from prefix
> > byte#          11 ->          18)
> >
> >    (GVAR_PFX6.FOR) JD (Block-0 yyddd)         =       11117
> >    (GVAR_PFX6.FOR) JD_START (Block-0 ccyyddd) =     2011117
> >    (GVAR_PFX6.FOR) JT (Block-0 hhmmss)        =      202746
> >
> >    (GVAR_PFX6.FOR) JD (Block-0 yyddd)         =       11117
> >    (GVAR_PFX6.FOR) JD_END (Block-0 ccyyddd)   =     2011117
> >    (GVAR_PFX6.FOR) JT (Block-0 hhmmss)        =      202746
> >
> >    (GVAR_PFX6.FOR) blk id =           2, pro id =           4, blk cnt =
> >     48036
> >    (GVAR_PFX6.FOR)    lidet =           6, licha =           4, risct =
> >       185
> >    (GVAR_PFX6.FOR)    SPS time: year        2011 day of year         117
> > hh:mm:ss           20:          27:          50 msec         204
> >    (GVAR_PFX6.FOR)    (The above date/time information comes from prefix
> > byte#          35 ->          42)
> >
> >    (GVAR_PFX6.FOR) List time tags for numerous specific Imager events:
> >
> > GVARINFO:    (GVAR_PFX6.FOR) NOTE:  Areafile #        2000 line #
> > 369 prefix DOES NOT CONTAIN a band list.
> >
> >
> > (GVARINFO.PGM) DONE!
> >
> >  year day hh:mm:ss msec
> >  2011 117 20:27:46  265          current SPS time
> >  2011 117 20:27:16  738          time of current header block
> >  2011 117 20:27:17  128          time of current trailer block
> >  2011 117 20:27:16  148          time of lagged header block
> >  2011 117 20:27:16  538          time of lagged trailer block
> >  2011 117 20:25:18  765          time of priority frame start
> > time:  invalid                   time of normal frame start
> >  2011 117 20:27:40  523          time of last spacelook calibration
> >  2011 117 20: 9:12  905          time of last electronic (ECAL) calibration
> >  2011 117 20: 9:33  826          time of last blackbody calibration
> >  2011 117 20: 8:27  956          time of last star sense
> >  2011 117 20:15:10  477          time of last ranging measurement
> >  2011 117 20:27: 4  577          time tag of current IR calibration set
> >  1995 334 12: 0: 0    0          time tag of current visible NLUT set
> >  2007 348 15:14:36    0          time tag of current limits sets
> >  2011 117 15:45:20   71          time tag of current O&A set implemented
> >
> >
> > The operative two lines were:
> >
> >   LOC/AREAS.2000      27 Apr 11117   20:25:00      20:27:46       4
> >
> > GVAR_PFX6.FOR) Block-0 time: year        2011 day of year         117
> > hh:mm:ss           20:          27:          46 msec         265
> >
> > The times indicated for the line being interrogated are the same: 20:27:46.
> > The GVARINFO listing is more detailed as it shows the time down to the
> > millisecond:
> > 20:27:46.265
> >
> > Now, my question is "use the time for what"?
> >
> > The TIME= time that one specifies for commands like IMGDISP
> > and IMGLIST is the nominal time of the image (which is 20:25:00) in
> > the example).  The actual time of the line being scanned in this
> > case was 20:27:46.  My previous comments were that one has to pay
> > attention to the time(s) of the scan lines of interest when
> > doing comparisons to things like radar.  For the image line I
> > interrogated, its scan time is a LOT closer to the nominal time
> > of the radar scan than its nominal time is.  My conjecture is
> > that the 20:28 radar image is the one to use in comparison
> > to the 20:25 satellite image ** for your region of interest **.
> >
> > Cheers,
> >
> > Tom

Cheers,

Tom
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Ticket Details
===================
Ticket ID: JBA-785900
Department: Support McIDAS
Priority: Normal
Status: Closed