[ncl-talk] Visualization of SAF NWC products
Rick Brownrigg
brownrig at ucar.edu
Tue Feb 16 22:46:38 MST 2016
Hi,
I have been able to verify on my end that this problem is version specific
to proj4. The script works fine on the slightly older 4.8.0 versions, but
appears in the latest 4.9.1 proj4 (Sakis, can you verify this on your side
-- what version gets reported if you simply type "proj" on the command
line?). This seems like a bug in the proj4 library, but I can find no
mention of it in their issues database. I will try to gather more
information and file a bug report with the proj4 folks.
In the meantime, Sakis, are you able to down-version your proj4 library to
something like 4.8.0?
Rick
On Mon, Feb 15, 2016 at 2:46 AM, Athanasios Karagiannidis <thankar at live.com>
wrote:
> Dear Rick,
>
> I understand that you did not manage to identify the problem.
> If that is the problem , are there any suggestions regarding the
> visualization of SAF NWC (basically meteosat) products?
>
> Sakis
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
>
> ------------------------------
> Date: Mon, 8 Feb 2016 20:38:47 -0700
> Subject: Re: [ncl-talk] Visualization of SAF NWC products
> From: brownrig at ucar.edu
> To: thankar at live.com
>
>
> Hi Sakis,
>
> Offhand I don't know what is going on here. It almost appears that the
> proverbial "rug has been yanked out from under us", with respect to the
> projection software -- I've used that package for over a dozen years, and
> "+proj=latlon" is/was by all accounts a legitimate projection spec. I get
> the same result as you on my system, which has the latest proj4 release --
> I want to try and track down a system with an older release in the morning
> and see if I get the same results.
>
> Rick
>
> On Mon, Feb 8, 2016 at 9:10 AM, Athanasios Karagiannidis <thankar at live.com
> > wrote:
>
> Dear Rick
>
> I'm coming back with a problem regarding an earlier problem i had some
> time ago.
>
> I was trying to visualize Meteosat projection data (for example the
> CTTH_HEIGHT parameter in the h5 file) and you provided the script i attach
> which is supposed to draw the png i also attach.
>
> However when i try to execute, i get the following message:
>
> (0) Span in X direction (meters): 2.16929e+06
> (0) Span in Y direction (meters): 1.53321e+06
> (0) calculated maxX: 3.03041e+06 vs. reported in file: 3.03041e+06
> (0) calculated maxY: 4.4706e+06 vs. reported in file: 4.4706e+06
> FATAL ERROR: Can not make a projection out of <+proj=lonlat>
> fatal:TransformCoordinate: Couldn't transform coordinates.
> fatal:["Execute.c":8578]:Execute: Error occurred at or near line 38 in
> file geos2LL.ncl
>
> (0) longitude range: 861115.75, 3030407.25
> (0) latitude range: 2937395, 4470601
> (0) gsn_csm_map_ce: Warning: you set mpMaxLonF to a value > 180, but
> (0) didn't set mpCenterLonF. Setting mpCenterLonF to
> 1945761.5
> warning:MapTransInitialize: mpMinLonF out of range: resetting
> warning:MapTransInitialize: mpMaxLonF out of range: resetting
> warning:MapSetTrans: map limits invalid - using maximal area
> warning:mpMapLimitMode is not a valid resource in map at this time
> (0) get_lat_values: Warning: Your latitude values do not fall between
> -90 and 90 inclusive.
> (0) You will not get 'nice' latitude labels.
> warning:Attempt to reference attribute (minor) which is undefined
>
> I think the problem begins at *dstProj = "+proj=lonlat"*.
> As a result nothing is plotted.
> Could you help me?
>
> I attach a data file in case you need it.
>
> Thank you in advance
>
> Sakis
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
>
> ------------------------------
> Date: Fri, 5 Jun 2015 15:16:34 -0600
> Subject: Re: [ncl-talk] Visualization of SAF NWC products
> From: brownrig at ucar.edu
> To: thankar at live.com
> CC: haley at ucar.edu
>
> Hi Sakis,
>
> The file does indeed seem to have all the requisite projection information
> in it to calculate latlon coordinates, using, our interface to the proj4
> library. I've attached a script that does just that. I've also attached
> the the plot it generates. I'm a bit troubled by the shape of the lat/lon
> grid, and by the fact that the spans in X/Y in meters do not align with
> what gets reported in Google Earth. However, the native projection is
> "geostationary view", and its possible that it imparts rather severe
> distortion of distance at the edges of the projection, so maybe the values
> are reasonable.
>
> Do you have a feel for what the shape/extent of your data should look like?
>
> Let me know what you think...
> Rick
>
>
>
> On Fri, Jun 5, 2015 at 12:53 AM, Athanasios Karagiannidis <
> thankar at live.com> wrote:
>
> Dear Mary
>
> Thank you for your help!
>
>
> The speed of the code was indeed an issue.
>
> Regarding the lat / lon issue:
> 1. Yes, they are not equally spaced.
> 2. Yes, the whole information about the way the rasterized data
> should be assigned to lat/lon is (to my knowledge) included in the h5 files
> attributes.
> 3. I have a way to bypass the problem by loading 2 separate files
> that provide lat/lon info. However I would like to be independent of them,
> for a series of reasons.
> I’m looking forward to Rick’s response.
>
> Kind regards
>
> Sakis
>
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
>
> ------------------------------
> Date: Thu, 4 Jun 2015 22:59:55 -0600
> Subject: Re: [ncl-talk] Visualization of SAF NWC products
> From: haley at ucar.edu
> To: thankar at live.com
> CC: brownrig at ucar.edu
>
>
> Dear Sakis,
>
> You've been so patient, thanks! As a start, I recommend that you use
> raster mode, as it is much faster:
>
> res at cnFillMode = "RasterFill"
>
> The code ran in about 1 second, compared to minutes before.
>
> The issue here is that you don't have lat/lon arrays on the file, so you
> have to either construct them yourself, as you are trying to do with the
> fspan function, or else if you know the exact map projection, then you can
> just draw the contours in the correct map project, with res at tfDoNDCOverlay
> = True. This is basically telling NCL that you know what the projection
> is, and to not require lat/lon coordinates.
>
> I think the use of "fspan" to generate the lat/lon values may be too
> simplistic, as this is assuming your lat/lon values are equally spaced, and
> not rotated. I have a feeling that neither of these conditions are true
> for your data. But, I could be wrong! I just know that the plot doesn't
> look quite right if you run the script as it.
>
> I can't tell from your file what the correct map projection is, as I'm not
> familiar with the terminology it's using. It looks like the information is
> all there in the file attribute information:
> GEOTRANSFORM_GDAL_TABLE : -5570248.832537, 3000.403357, 0.000000,
> 5570248.832537,0.000000, -3000.403357
> PROJECTION : +proj=geos +a=6378169.0 +b=6356583.8 +lon_0=0.0
> +h=35785831.000, -3000.403357
>
> PROJECTION_NAME : GEOS<+000.0>a=6378169.0 +b=6356583.8 +lon_0=0.0
> +h=35785831.000, -3000.403357
> REGION_NAME : Greece000.0>a=6378169.0 +b=6356583.8 +lon_0=0.0
> +h=35785831.000, -3000.403357
> XGEO_LOW_RIGHT : 3030407.390714755
>
> XGEO_UP_LEFT : 861115.7635001335
> YGEO_LOW_RIGHT : 2937394.886643311
> YGEO_UP_LEFT : 4470601.002143549
>
> My guess is that you might be able to use one of our unadvertised,
> internal GDAL transformation routines to convert this information into
> lat/lon coordinates. I've CC'ed Rick Brownrigg who may know something
> about this.
>
>
> --Mary
>
>
>
> On Sun, May 31, 2015 at 1:48 AM, Athanasios Karagiannidis <
> thankar at live.com> wrote:
>
> Dear Mary
>
> I attached the latets script that was prepared for me along with a sample
> dataset (h5 file).
>
> Thank you for your interest and help.
>
> Sakis
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
>
> ------------------------------
> Date: Sat, 30 May 2015 15:34:05 -0600
> Subject: Re: [ncl-talk] Visualization of SAF NWC products
> From: haley at ucar.edu
> To: thankar at live.com
> CC: ncl-talk at ucar.edu
>
>
> Dear Sakis,
>
> Can you provide the data and the latest script that you are using, so we
> can take a look? You can use our ftp if you don't have a place to put it:
>
> http://www.ncl.ucar.edu/report_bug.shtml#HowToFTP
>
> --Mary
>
>
> On Thu, May 28, 2015 at 2:05 AM, Athanasios Karagiannidis <
> thankar at live.com> wrote:
>
> Good morning to all!
>
> Following the earlier conversation (to which I respond) I think I have the
> obligation to clarify some issues, since these conversations are available
> to all users, and they are used to solve various kinds of problems.
> After doing some more tests, I found out that the otherwise elegant and
> technically flawless script that was kindly prepared for me, does not
> illustrates correctly the CTTH_HEIGHT field. The problem is related to the
> fact that the line/column space of the raster data does not refer to a
> regular lat/lon space. In simple words the pixels of the raster data are
> not equal in lat/lon dimensions.
>
> Regarding more technical issues:
> XGEO_LOW_RIGHT, XGEO_UP_LEFT, YGEO_LOW_RIGHT, YGEO_UP_LEFT are not given
> in degrees but in meters.
>
> dims = dimsizes(CT) , lat = fspan(minLat, maxLat, dims(0)) and lon =
> fspan(minLon, maxLon, dims(1)) are producing a regular grid (which is
> not correct)
>
> It would be really helpful if a script could project correctly Meteosat
> fields (I think safnwc is using the Meteosat grid) but I’m not sure that
> such a thing exists.
>
> Kind regards
>
> Sakis
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
>
> ------------------------------
> From: thankar at live.com
> To: haley at ucar.edu
> Date: Sat, 21 Feb 2015 08:29:02 +0000
> CC: ncl-talk at ucar.edu
> Subject: Re: [ncl-talk] Visualization of SAF NWC products
>
> Mary, thank you for your input!
>
> Sakis
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
>
> ------------------------------
> Date: Fri, 20 Feb 2015 09:46:02 -0700
> Subject: Re: [ncl-talk] Visualization of SAF NWC products
> From: haley at ucar.edu
> To: thankar at live.com
> CC: huangwei at ucar.edu; ncl-talk at ucar.edu
>
> The issue with "namedcolor2rgb" is not really an issue. The code should
> still work. The error message is just misleading, but can be ignored.
>
> We have fixed the incorrect error message for the V6.3.0 release coming
> next month.
>
> --Mary
>
>
> On Fri, Feb 20, 2015 at 1:46 AM, Athanasios Karagiannidis <
> thankar at live.com> wrote:
>
> Wei,
>
> Your help is more than appreciated.
>
> I will update my NCL version.
>
> Kind regards
>
> Sakis
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
>
> ------------------------------
> From: huangwei at ucar.edu
> Date: Thu, 19 Feb 2015 09:23:14 -0700
>
> Subject: Re: [ncl-talk] Visualization of SAF NWC products
> To: thankar at live.com
> CC: ncl-talk at ucar.edu
>
> Sakis,
>
> Attached is script which looks more like what you see with HDFview,
> but used a whole user-defined color table.
>
> "gsdtol" is a standard color-table name, in NCL 6.2.1. Your NCL of 6.1.2
> is a little bit old, and I strongly suggest you update your NCL to the
> newest version.
>
> Compare the newly attached script and the script before,
> you'll be able to figure out that the difference is the projection applied.
> So you can turn on/off those options based on your requirement.
>
> A new png file is attached as well.
>
> Regards,
>
> Wei
>
>
>
> ================================================
> 1850 Table Mesa Dr.
> Boulder, CO 80307
> Phone: 303-497-8924
>
> On Thu, Feb 19, 2015 at 4:07 AM, Athanasios Karagiannidis <
> thankar at live.com> wrote:
>
> Dear Wei
>
> I'm more than thankful for your script! It is excellent in correctly
> reading my data and more or less what i wanted regarding the visualization.
> I have just 3 comments:
> 1. I would really like to see the drawn field (in example the CT) even
> over land. How can i do this?
> 2. When i run the script in my machine i get the following warnings:
>
>
>
> *(0) Warning: namedcolor2rgb: 'gsdtol' is not a valid named
> color.(0) Will return missing values for this color.*
> Is 'gsdtol' a custom made color? In this case maybe i should replace it.
>
> 3. In the example HDFView visualization i provided the grid was not
> "tilted" to the left (a projection issue i guess!). How should i make your
> visualization, so it looks like the HDFView one?
>
> Thank you in advance!
>
> Sakis
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
>
> ------------------------------
> From: huangwei at ucar.edu
> Date: Wed, 18 Feb 2015 13:26:21 -0700
> Subject: Re: [ncl-talk] Visualization of SAF NWC products
> To: thankar at live.com
> CC: ncl-talk at ucar.edu
>
>
> Sakis,
>
> You may take a look of the attached script and pdf file to see if these
> are what you wanted.
>
> Thanks,
>
> Wei
>
>
>
> ================================================
> 1850 Table Mesa Dr.
> Boulder, CO 80307
> Phone: 303-497-8924
>
> On Wed, Feb 18, 2015 at 1:38 AM, Athanasios Karagiannidis <
> thankar at live.com> wrote:
>
> Dear sirs/madams
>
> I want to visualize SAF NWC output data using ncl. They are included in an
> h5 file.
> These data are not in a simple lat-lon grid.
> After an earlier contact with you i managed to visualize them by creating
> such a grid, but i feel that the image is not accurate.
> What i want to help me with, is to tell me weather there is a standard way
> or an already existing script to visualize correctly that kind of data.
> To help you I provide the following:
>
> 1. A sample datafile.
> 2. The printVarSummary output
> 3. A screenshot of the HDFView visualization of the variable where the
> Variable info are shown (more or less the same info with printVarSummary).
> 4. The script i used (although, i do not think that you need that!). The
> lat/lon limits that i have n my script are not acurate. I used them to make
> the visualization.
>
>
> ---------- printVarSummary------------------------------
>
> ncl 2> printVarSummary(CT)
>
> Variable: CT
> Type: ubyte
> Total Size: 370688 bytes
> 370688 values
> Number of Dimensions: 2
> Dimensions and sizes: [DIM_000 | 512] x [DIM_001 | 724]
> Coordinates:
> Number Of Attributes: 11
> CLASS : IMAGE_INDEXED
> ID : CTTH_HEIGHTED
> IMAGE_COLORMODEL : RGBH_HEIGHTED
> IMAGE_SUBCLASS : IMAGE_INDEXED
> IMAGE_VERSION : 1.0GE_INDEXED
> N_COLS : 724
> N_LINES : 512
> OFFSET : -2000
> PALETTE : ��8�3
> PRODUCT : CTTHE_INDEXED
> SCALING_FACTOR : 200
>
>
> ---------------------------------------------------------------------------------
>
> ---------------- My Script
> ---------------------------------------------------
>
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>
> begin
> cdf_file = addfile("SAFNWC_MSG2_CTTH_200812121100_Greece______.h5","r")
> CT = cdf_file->CTTH_HEIGHT(:,:)
>
> res = True
>
> lat = fspan(50,20,512) ; A.K. -- reverse the matrix
> lon = fspan(10,30,724)
> CT!0 = "lat" ;-- set name of CT dimension 0
> CT!1 = "lon" ;-- set name of CT dimension 1
> CT&lat = lat ;-- assign lat array to CT
> CT&lon = lon ;-- assign lon array to CT
> CT&lat at units = "degrees_north" ;-- set the units of the named
> coordinate lat
> CT&lon at units = "degrees_east" ;-- set the units of the named
> coordinate lon
>
> res at gsnAddCyclic = False
> res at tiMainString = "Default Color" ; main title
> res at cnFillOn = True ; turn on color fill
> res at mpMaxLatF = 50 ; choose
> subregion
> res at mpMinLatF = 20
> res at mpMaxLonF = 30
> res at mpMinLonF = 10
>
> xwks = gsn_open_wks("pdf","CloudTops")
> plot = gsn_csm_contour_map(xwks,CT,res)
> end
>
>
> --------------------------------------------------------------------------------
>
> Thank you in advance.
>
>
> Sakis
>
>
>
>
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
>
>
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