How to display picture from AVHRR data ?

[francoisborel]

Hello everyone,

Another question.

I try to take pictures in infrared of some hurricanes. But when i use Noaa class after 1994, i get little size area files with very low quality.
I attached file example : bad_ir.jpg

So i thank that AVHRR format could give me better pictures ... And so i have created a local ADDE server
See attached file server_parameter.jpg

But when i choose the image type in the Data explorer, i have an error
See attached file : error_message

In the directory of the server i have several files. Here the dir list :

04/12/2016 21:30 3ÿ968ÿ082 NSS.GHRR.ND.D95239.S0911.E1105.B2225556.WI
04/12/2016 21:30 4ÿ422ÿ082 NSS.GHRR.ND.D95239.S1100.E1243.B2225657.WI
04/12/2016 21:30 72ÿ762 NSS.GHRR.ND.D95239.S1239.E1433.B2225758.GC
04/12/2016 21:31 25ÿ155ÿ578 NSS.HRPT.ND.D95239.S1106.E1117.B2225656.WI
04/12/2016 21:30 900ÿ026 NSS.HRPT.ND.D95239.S1246.E1259.B2225757.WI

Could you help me for this case ? Perhaps i made a bad choice with AVHRR. Perhars an another solution, or something i don't understand on McIdas...

I thank you a lot.

Cheers
françois

[bobc]

Hello -

Can you please post the five files you listed to our anonymous ftp? Here is how you would do that from a command prompt:

ftp ftp.ssec.wisc.edu
user: anonymous
password: your email address
bin
cd pub/incoming
put filename

Let me know when the files are posted and I'll take a look at them.

Thanks -
Bob Carp
McIDAS Help Desk

[francoisborel]

Hello

It's done. The filename is : format_avhrr_francoisborel_yahoo_fr.rar

thank you a lot.

Note that there is two direction in my question. How to read AVHRR format, and perhaps you have already see the problem with the quality of the infrared pictures (visible are good) and perhaps you have anoter way to get good pictures..

Thank you again..

françois

[bobc]

Hello -

As for the low quality images, I'll assume that the data was loaded with a local ADDE dataset. If this is the case, once the field is selected in the Field Selector, navigate to the Advanced tab in the lower right corner of the tab. By default, you may notice that the full resolution isn't being displayed (as is the case in the below screenshot):

Notice that the Line and Ele mags are set to -2, so the resolution is 8km (the native resolution of the data is 4km). You can easily choose to display the full domain of the data at its native resolution by clicking the green arrow button to the right of the Image Size text boxes. Once this is done, click Create Display.

As for the AVHRR data, I went to ftp://ftp.ssec.wisc.edu/pub/incoming and there's no file called "format_avhrr_francoisborel_yahoo_fr.rar". Can you please try re-posting it?

Thanks -
Bob

[francoisborel]

I'm sorry for the file. RAR forbidden on the server. I didn't see it ..
I put a file named : format_avhrr.zip. It's now ok.

Thank you for the another answer. No local server. I used to go in General / Files Directories.. Now i use a local server, and i already see that i can load a lot of visibles area files without any problem. When i used the Files / Directories option, i loaded the files four by four because it was very very long..

I begin to understand. Thank you.

I will try the solution for the IR quality..

You are very helpful..

Cheers.
françois

[francoisborel]

Hello

I try to do the actions for the low quality in IR band, but i don't find the Advanced tab.. I put a screenshot. I have only the tab "Times".

Perhaps i'm not in the correct window...

Thank you...

françois

[francoisborel]

Good evening Bob,

It's okay for the "advanced" tab. Sometimes i can't see it but generaly this tab is displayed...

For the IR low quality, it is better when i activate higher quality in "advanced" tab, but we stay in a low quality.. So i think the solution is to get the good AREA files. I have open an issue at Noaa.

So we will stay on the primary object of the post. I think i have more chances with AVHRR..

Thank you. Have a nice day.

Regards
françois

[bobc]

Hello -

Thanks for letting us know that your Advanced tab sometimes appears. There's a known bug that these tabs can occasionally disappear until you change the field selected. In other words, from your screenshot (ScreenShot002.jpg) if you changed from Raw to Temperature then the Region and Advanced tabs would likely appear.

As for the AVHRR data, I'm not having any luck with it in McIDAS-V or our other software package, McIDAS-X. We do have other AVHRR Level 1b data from 1995 that works in both packages. A few questions about your data:

1. Was this data ordered from NOAA CLASS or did it come from another source?
2. Did you geographically subset your data at all?
3. Did you order all of the bands?

Per the documentation on the Local ADDE Data Manager page of the McIDAS-V User's Guide:

Note: This server works with data ordered from NOAA CLASS. This data must not be geographically subsetted. The data can be ordered in 10-bit files or 16-bit files (as long as all channels are included).

Thanks again -
Bob

[francoisborel]

Hello Bob

Thank you... Here are the details :

Was this data ordered from NOAA CLASS or did it come from another source?
Fborel : Yes, i download my data on Noaa Class

Did you geographically subset your data at all?
Fborel : I don't know. On Noaa Class parameters, i see a checkbox "Subset Flag/Geo.". This box is check, but is seen only in GVAR paramter et not on AVHRR parameter.. (http://www.nsof.class.noaa.gov/saa/prod ... references)... How can i do that ?

Did you order all of the bands?
Fborel : No ! So i modify my preferences on Noaa Class to make another test

And after your answer, i make this test :
- Files downloaded on noaa class
- All bands checked
- I create an ADDE server with "NOAA AVHRR L 1b" format

=> When i connect to the server, all is ok. When i choose my image type, the software runs and runs without stopping (i wait about 5 minutes)..
=> I make a test with "Metop AVHRR L 1b" format (i read somewhere to try this), but i have the same result. The request runs, without stop and without any error message.

Thank you Bob, thank you.

Have a nice week end

Cheers
françois

[francoisborel]

Hello Bob,

Hope all is okay for you.

Complement with my answer. I read wrong...
>Note: This server works with data ordered from NOAA CLASS. This data must NOT be geographically subsetted.

I have not any checkbox to subset or not subset the data of NOAA CLASS (AVHRR). So it seems that i have all to success my data import. But i stay with the same problem. I retry and wait longer. Perhaps..

Thank you
Cheers

françois