Simple ASCII

Overview

Simple ASCII is a text column representation timeseries data that IRIS DMC now provides. This representation makes it very simple to import into other utilities such as spreadsheets and mathematical analysis programs. There are two kinds of Simple ASCII representation:

  • SLIST: single column listing of sample values with only a starting time index for the evenly spaced samples.
  • TSPAIR: double column listing, with each sample value preceded by a time stamp.

The sample value listings are preceded by a header, which describes the station, channel, sample rate, data format, and the numeric type of the sample representation. An example is shown here:

TIMESERIES IU_ANMO_00_BHZ_M, 288000 samples, 20 sps, 2010-02-27T06:30:00.019538, TSPAIR, INTEGER, COUNTS
2010-02-27T06:30:00.019538  -47237
2010-02-27T06:30:00.069538  -47304
2010-02-27T06:30:00.119538  -47367
2010-02-27T06:30:00.169538  -47430
2010-02-27T06:30:00.219538  -47499
2010-02-27T06:30:00.269538  -47572
2010-02-27T06:30:00.319538  -47653
2010-02-27T06:30:00.369538  -47747
2010-02-27T06:30:00.419538  -47844
2010-02-27T06:30:00.469538  -47941
2010-02-27T06:30:00.519538  -48049
2010-02-27T06:30:00.569538  -48170
2010-02-27T06:30:00.619538  -48293
2010-02-27T06:30:00.669538  -48419
2010-02-27T06:30:00.719538  -48543
2010-02-27T06:30:00.769538  -48668
2010-02-27T06:30:00.819538  -48796
[......cut here for brevity.....]

Detailed description

Each contiguous time series segment (no gaps or overlaps) is represented with a header line followed by data samples in one of two styles: either sample lists or time-sample pairs. There are no restrictions on how the segments are organized into files, a file might contain a single segment or many, concatenated segments either for the same channel or many different channels.

Header lines have the general form:

"TIMESERIES SourceName, # samples, # sps, Time, Format, Type, Units"

Header field descriptions:

Field Description
SourceName “Net_Sta_Loc_Chan_Qual”, no spaces, quality code optional
  1. samples
Number of samples following header
  1. sps
Sampling rate in samples per second
Time Time of first sample in ISO YYYY-MM-DDTHH:MM:SS.FFFFFF format
Format SLIST’ (sample list) or ‘TSPAIR’ (time-sample pair)
Type Sample type ‘INTEGER’, ‘FLOAT’ or ‘ASCII
Units Units of time-series, e.g. Counts, M/S, etc., should not contain spaces

Example header (no line wrapping):

TIMESERIES NL_HGN_00_BHZ_R, 11947 samples, 40 sps, 2003-05-29T02:13:22.043400, SLIST, INTEGER, Counts

Sample value format

For the SLIST (sample list) format, samples are listed in a single column, optionally many columns may be used with the time-series incrementing from left to right and wrapping to the next line. The time of the first sample is the time listed in the header.

For the TSPAIR (time-sample pair) format, each sample is listed on a separate line with a specific time stamp in the same ISO format as used in the header line.

Example SLIST format:

TIMESERIES NL_HGN_00_BHZ_R, 12 samples, 40 sps, 2003-05-29T02:13:22.043400, SLIST, INTEGER, Counts
2787
2776
2774
2780
2783
2782
2776
2766
2759
2760
2765
2767

Example TSPAIR format:

TIMESERIES NL_HGN_00_BHZ_R, 12 samples, 40 sps, 2003-05-29T02:13:22.043400, TSPAIR, INTEGER, Counts
2003-05-29T02:13:22.043400  2787
2003-05-29T02:13:22.068400  2776
2003-05-29T02:13:22.093400  2774
2003-05-29T02:13:22.118400  2780
2003-05-29T02:13:22.143400  2783
2003-05-29T02:13:22.168400  2782
2003-05-29T02:13:22.193400  2776
2003-05-29T02:13:22.218400  2766
2003-05-29T02:13:22.243400  2759
2003-05-29T02:13:22.268400  2760
2003-05-29T02:13:22.293400  2765
2003-05-29T02:13:22.318400  2767