IRIS Knowledge Base

Category » Waveforms

There were 26 articles found in this category:

1. Do all SAC responses have one additional zero?
   Q: I see that the instrument response in RESP and SAC file formats is slightly different in the Poles and Zeroes section. In the SAC file, there is an additional "one zero". Is the SAC response file automatically converted by rdseed to displacement? Most instrument responses are reported in vel ...
2. Is there a limit on the number of lines I can have in a BREQ_FAST request? Limit on the size of data?
   Q: Is there a limit on the number of lines I can have in a BREQ_FAST request? Limit on the size of data? A: There are a number of variables that will contribute to answering your question. Here are a general set of guidelines which should help you to generate BREQ_FAST-style requests that wi ...
3. How many simultaneous ws/bulkdataselect requests can I send at one time?
   Q: How many simultaneous ws/bulkdataselect requests can I send at one time? A: Our bulkdataselect web service, which provides bulk request access to miniseed data from the IRIS DMC archives, is continually challenged to provide the fastest service to the widest number of users. In order to cont ...
4. Does IRIS support any simple ASCII data formats that contain timeseries data?
   Q: Does IRIS support any simple ASCII data formats that contain timeseries data? A: Yes. IRIS now provides as an alternative output two forms of columnar text representations of data. Currently, IRIS web services and rdseed can write out miniSEED data as ASCII. An example is shown below. Plea ...
5. How do I go from miniSEED to SEED?
   Q: I received some raw data in miniSEED format. How do I go from miniSEED to SEED? I have the station's location, elevation, and poles & zeros. A: The easiest way to get full SEED from miniSEED is to first get a dataless SEED volume There are numerous network dataless volumes available onl ...
6. Software for accessing data in near real-time
   Q: I'm working on a project in where we want to display seismic data in real-time. We are interested in two stations to begin with 223.TA and 324.TA eventually we will have more stations. I would like to know if this data can be display in real-time with the software you have in your web site. D ...
7. Delayed exports from seedlink
   Q: At the moment, a station I am observing with seedlink will have delays of just a couple of minutes, but this afternoon I was seeing delays closer to 10 minutes. I am pretty naive on this subject, but from my Earthworm and Antelope experiences I don't see why data should ever be more than may ...
8. I think my data looks funny and none of these other questions address my problem. Who can I ask?
   The general place to post questions about data is the data-issues mailing list. If a question posted to this list cannot be answered by the list members, an IRIS DMC staff member will either directly notify or re-direct the reporter to the appropriate network operator for the data in question.
9. How do I get data from the 2010 Maule earthquake?
   Q. How do I get portable station data from the 2010 Maule earthquake in Chile? A. Data from aftershock deployments are all available. The data from the French, British and US deployments are available through the IRIS DMC. They are available using the virtual network code _IMAD. Specific netwo ...
10. Historical Earthquake Archive
    SeismoArchives - Seismogram Archives of Significant Earthquakes of the World The main purpose of these SeismoArchives is to preserve historical seismograms and related materials in computer data files so that they are readily accessible online as source materials for research. SeismoArchives are ...
11. Does IRIS perform quality assurance on the data it receives?
    A: Yes. IRIS DMC developed the QUACK system to perform metrics-based quality assurance logging on near-real time data feeds buffered at IRIS DMC. With QUACK, you can browse statistics by network and station as well as by a span of time, where appropriate. QUACK also provides a query-oriented r ...
12. Waveform Request Tools
    Data Access Navigator Tool To assist new and experienced users alike in navigating IRIS DMC's waveform request tools, a navigation page has been provided on the web that helps to highlight the most important methods of data access. Please consult the Data Access Tool here. Below are spe ...
13. How do I interpret the SAC ASCII data files?
    Q: I have a few questions regarding the Mexicali Event files that I downloaded: 1. I attached a image showing all the files I received from the Seismogram tab -- I understand "BK.JRSC." refers to the server and the station name, but can you confirm: "BQ2, BQ3, etc." refer to the various channel ...
14. Can no longer get BHE or BHN channels
    Q: I am curious if there was a problem with the BHE and BHN components of station PAYG as part of the IU network? I requested to download data yesterday and the BHZ channel shows data through 2010.180 but the BHE and BHN channels only show data up to 2010.107. Also there appears to be two BHZ ...
15. Including IRIS-provided data in sample code
    Q: I'm using a single three-channel seismic recording of one earthquake to include in a MATLAB code distribution. I just want to know if it's OK to include the sample dataset in my MATLAB package. A: In general, the data at IRIS DMC is considered open for your use. Please be sure to cite tha ...
16. ms2sac error for miniseed records
    Q: I concatenated a bunch of miniseed records together and then ran “ms2sac” to convert them as SAC file. I got “Max slew exceeded - time series prematurely terminated”, the miniSEED is about 30M, and the SAC file becomes 17K. A: I'm guessing ms2sac probably cannot ha ...
17. Combining miniseed files
    Q: I am using DHI2mseed.jar to request data from IRIS. For some stations (e.g. UALR of NM network), each miniSEED data file lasts only about a few minutes. Can we combine them as one miniSEED file as continuous data? A: Yes, miniSEED files can be combined simply by 'cat'ing them together assum ...
18. VASE connection problem
    Q: I have installed Vase, but I can not connect to any server and it goes into offline mode. A: One possibility is that you have a firewall in place that is preventing you from contacting certain port numbers. Can you verify whether you can connect to dmc.iris.washington.edu:6371 ? Telnet ...
19. Downloading data from the IRIS DMC using FTP or HTTP robustly
    It is common to download data using either FTP or HTTP from the IRIS DMC. Most of these downloads are completed quickly and without interruption. On occasion, a user's connection to the DMC is broken before the download is complete. This can be due to system problems at the user's end, networ ...
20. What channels are available and what channels should I request?
    Q: What channels are available and what channels should I request? A: There are a number of tools you can use to get channels that are available for a given station. An easy path is to use MDA to discover which channels are operating for a station at a particular time. You can also check for d ...