Overview
Simple ASCII is a text column representation timeseries data that EarthScope 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 |
|
Number of samples following header |
|
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
