IRIS Knowledge Base

Category » Metadata

There were 15 articles found in this category:

1. How accurate are the station latitudes and longitudes?
   USArray TA station coordinates are measured by handheld GPS and reported to five decimal places of precision. IRIS DMC internally can store up to six decimal places of precision for latitude and longitude (this is the SEED specification). Many of our tools only display up to two decimal places, ...
2. 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 ...
3. 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 ...
4. 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 ...
5. What are the fields in a RESP file?
   Notes about the meaning of RESP files were posted by Sheila Peacock to the sac-help mailing list, which follow. Meaning of numbers in rdseed RESP files Here is a sample rdseed RESP file, which is output if you ask rdseed to output responses: * RESP.IU.FURI.00.BHE: "RESP" file for FURI compone ...
6. 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 ...
7. How do I remove the instrument response from the data?
   Q: How do I remove the instrument response from the data? A: Data is normally delivered to users in a raw recorded value that does not reflect the scale and characteristics of the original ground motion. The instrumentation introduces distortion and scaling of the data and therefore must be re ...
8. How to get a dataless SEED for stations and channels in a region
   Q: How can I get a dataless SEED for all stations and channels within a geographic bounding box? A: SeismiQuery The SeismiQuery page at http://www.iris.edu/SeismiQuery/breq_fast.htm can do this. The user inputs query parameters into a form to delimit a BREQ_FAST request. The user may input que ...
9. How can I get access to RESP files of stations?
   RESP files can be downloaded from IRIS DMC or generated from a dataless SEED using software tools. With a dataless SEED file, rdseed can generate a RESP file. PDCC can also write the contents of a dataless SEED for a selected station in RESP format. IRIS DMC keeps a RESP FTP file reposi ...
10. How can I create my own dataless SEED?
    A dataless SEED volume contains the metadata for a request only, including instrument responses, instrument coordinates, compression type, etc. Getting or creating a Dataless SEED File: 1. Generate a request for a dataless using the [online form] 2. Submit a BREQ_FAST style request to dataless@i ...
11. What is a blockette?
    Blockette - a data structure in SEED consisting of an identification code, a length specification and a sequence of related data fields. These are the basic building blocks of the SEED format and each type of blockette serves a specific purpose in conveying station information and details about ...
12. How to view precise station coordinates
    IRIS uses two decimals for station coordinates in mda and gmap so that users get relative locations for making maps and viewing icons on maps. You can view station coordinates with more precision using other methods of inquiry, for example SeismiQuery http://www.iris.edu/SeismiQuery/station.h ...
13. What is SQL?
    SQL stands for Structured Query Language - a database computer language designed for managing data in relational database management systems Learn more What happened to the page: Write Your Own SQL Query ? In the past, SeismiQuery had a web form that allowed users to run SQL queries against the ...
14. What is a RESP file?
    A RESP file is an ASCII representation of SEED instrument response information. Generally RESP files only contain the subset of SEED headers that represent an instrument response, they do not contain station coordinates or other metadata available in SEED headers. SEED, and consequently RESP, ...
15. What is a dataless SEED volume?
    A dataless SEED volume contains the metadata for a request only, including instrument responses, instrument coordinates, compression type, etc.. This dataless volume can be used in combination with a miniSEED volume (as extracted from the BUD filesystem) with rdseed. A dataless, by definition, c ...