unable to load SEGY or miniseed data, tests fail

Users Mailing List Archive
1

Hi all,

I'm trying to use obspy on Ubuntu 12.04, but have been unable to read in any data. I have tried installing in different ways and have had different errors. Currently I have installed using easy_install and get this:

In [3]: st = read(‘http://examples.obspy.org/RJOB_061005_072159.ehz.new’)

obspyTests.txt (28.5 KB)

2

Hi Aaron,

I assume the following test report http://tests.obspy.org/?id=1513
belongs to you. Therefore only the modules obspy.core and obspy.segy
seem to be installed.

3

Thanks for your quick, helpful reply, Robert! I can now load gse2 and mseed files, and tests all work.

I am still having trouble loading the SEGY files that I need to work with, though.

When I use obspy.core.read, I get:
TypeError: Unknown format for file 12.160.13.00.00.B13B.4

When I use obspy.segy.segy.readSEGY, I get:
SEGYError: Unable to determine the endianness of the file. Please specify it.

When I pass the endianness to, readSEGY I get:
NotImplementedError: Extended textual headers are supported yet. Please contact the developers.

I attached an example of one of the files that I need to load. How can I make this work?

Thanks,
Aaron

12.160.05.00.00.TP01.V (1.37 MB)

4

Aaron,

>

When I pass the endianness to, readSEGY I get:
NotImplementedError: Extended textual headers are supported yet. Please
contact the developers.

I guess this should state "Extended textual headers are NOT supported yet" ;/

however, try to play with the textual_header_encoding option - see
http://docs.obspy.org/packages/autogen/obspy.segy.core.readSEGY.html
- maybe the autodetection does not work for some reasons - I don't have ObsPy running on my current working device to test this here.

If this fails we have to wait for Lion to have a closer look at this file.

Cheers,
Robert

5

Hi Robert,

I created these files from rt130 output using IRIS Passcal's ref2segy program. I probably don't want extended textual headers! I can't find any option in ref2segy to make "normal" headers...

Thanks,
Aaron

6

Hi all.

I guess this should state "Extended textual headers are NOT supported yet" ;/

Yea definitly.

I'll have a look at the file after the game tonight. If it really has extended textual headers, which would be really nice because I have not yet seen a file with those, I'll implement them. The fact that the endianness detection fails might hint a deeper rooted problem, though.

Best wishes,

Lion

7

Today I was informed that the IRIS SEGY header format is nothing but 400 bytes, and has no textual component at all. I haven't had a chance to verify if that's how my files are, but I expect it is. I've converted all of my data to miniseed and obspy is working great for me now. Thanks!

Aaron

8

Hello Aron,

I did some checks and you are right. The PASSCAL programs all write a heavily modified version of SEG Y. obspy.segy was actually initially intended to be able to handle these modified versions but it was never needed so far and thus it does not work right now…

I'll get to it but it does require some significant changes to obspy.segy so it will take a while.

Best wishes,

Lion

9

Hi all,

In hopes to clarify; PASSCAL SEGY-Y is a way to use the SEG-Y format for long (passive data like), individual (non-gather) traces.

PASSCAL SEG-Y is SEG-Y with 1 trace per file; so the reel, binary, and textual headers aren't needed and dropped.
1 file = 1 trace header | 1 data trace

Since the SEGY has a max # samples of 32767 with 16bits, we use 32 bits at