Real-time helicorder view for one stream


scheli visualizes waveforms from a single stream or multiple stations mimicking a drum-recorder plot (see scheli in GUI mode):

  • scheli plots one configurable trace in helicorder style in the GUI (GUI mode).

  • Configurable GUI: trace colors, visualized time spans, number of rows, data filtering, amplitude ranges and much more.

  • Automatic image capturing: Capture helicorder images at configurable time intervals of one trace in GUI mode or a set of multiple channels in capture mode. The images can be used, e.g. for showing data images on web sites.


scheli in GUI mode


  1. GUI mode - Simple helicorder window:

    • Learn about the plenty command-line options for scheli:

      scheli -h
    • Start scheli with the configured values and informative debug output:

      scheli --debug
    • Let scheli show data from the CX station PB01 for the previous 5 hours overriding configuration by command-line paramaters:

      scheli --stream CX.PB01..HHZ --rows 10
    • Define the data request window by end time and duration; scale traces to the maximum amplitude per row:

      scheli --stream IU.TSUM.00.BHZ --end-time "2021-04-22 14:00:00" --time-span 600 --amp-scaling row
  1. Capture mode - Image capturing:

    Capture the helicorder plot for 3 stations in intervals of 10 seconds. The data is retrieved using seedlink and the plots are stored as PNG images. The image files are named according to network, station, stream and location codes of the requested stations. Command-line parameters override the module configuration.

    scheli capture --stream "CX.PB01..HHZ,CX.PB02..HHZ,CX.PB04..HHZ" --interval 10 -o "/tmp/heli_%N_%S_%L_%C.png" -H localhost -I slink://localhost

    The output file names will be generated based on network code (%N), station code (%S), location code (%L) and stream code (%C):



Specifc scheli parameters are adjusted in the module configuration. Colors of traces etc. can be adjusted by setting the scheme parameters in the global configuration of scheli. For alternating colors between the traces set the parameters scheme.colors.records.foreground and scheme.colors.records.alternateForeground in scheli.cfg:

# The general color of records/traces.
scheme.colors.records.foreground = 4286F4

# A general trace color of the alternate trace (eg scheli).
scheme.colors.records.alternateForeground = B72D0E



scheli inherits global options.


Type: list:string

List of stream codes to be plotted (net.sta.loc.cha). If not in capture mode only the first stream is shown. When using a list, the first entry is considered. Use commas for separating streams.

Example: GR.MOX..BHZ


Type: string

Filter to be applied on the data.


Type: integer

Filter to be applied on the data. Default is 48.


Type: double

Unit: s

Length of data per trace. Default is 1800.


Type: string

The time format used to print the start and end time of the whole plot (upper right corner). The format specification is the one used in the strftime function (man strftime). Default is %F.


Type: boolean

Sets current time to last data sample Default is false.


Type: integer

Unit: px

Line width of traces. Default is 1.


Type: list:string

A list of alternating row colors cycled through for painting traces. Default is FF0000, 0000FF.


Type: boolean

Use anti aliasing to plot the traces. The default uses the settings from scheme.records.antiAliasing Default is false.

Type: boolean

Add stream description to traces. Default is true.


heli.amplitudeRange.* Gain-corrected amplitudes given in units of the sensor, e.g. m/s.


Type: string

Define the method to scale traces within rows. Possible values are:

minmax: Scale all rows to configured minimum and maximum amplitudes configured by amplitudeRange.min and amplitudeRange.max.

row: Scale each row to the maximum within this row. Default is minmax.


Type: double

Unit: unit of input data

Minimum amplitude to show in trace. Requires amplitudeRange.scale = "minmax". Default is -0.00001.


Type: double

Unit: unit of input data

Minimum amplitude to show in trace. Requires amplitudeRange.scale = "minmax". Default is 0.00001.


heli.dump.* Control dumping of PNG images. Execute “scheli capture” for image generation in the background without the graphics.


Type: integer

Unit: s

Image creation interval. Negative values disable image dumping. If enabled, images are generated at the configured interval. Default is -1.


Type: string

Name of output file. The filename can contain placeholders that are replaced by the corresponding streamID parts:

%N : network code

%S : station code

%L : location code

%C : channel code

Placeholders are important if more than one stream is given and capture mode is active. Default is /tmp/heli_%N_%S_%L_%C.png.


Type: integer

Unit: dpi

Image resolution Default is 300.


Type: integer

Unit: px

Number of pixels horizontally Default is 1024.


Type: integer

Unit: px

Number of pixels vertically Default is 768.


Type: path

Defines the path to a script that is called whenever an image has been captured and written to disc. The only parameter is the path to the generated image.



-h, --help

show help message.

-V, --version

show version information

--config-file arg

Use alternative configuration file. When this option is used the loading of all stages is disabled. Only the given configuration file is parsed and used. To use another name for the configuration create a symbolic link of the application or copy it, eg scautopick -> scautopick2.

--plugins arg

Load given plugins.

-D, --daemon

Run as daemon. This means the application will fork itself and doesn’t need to be started with &.

--auto-shutdown arg

Enable/disable self-shutdown because a master module shutdown. This only works when messaging is enabled and the master module sends a shutdown message (enabled with --start-stop-msg for the master module).

--shutdown-master-module arg

Sets the name of the master-module used for auto-shutdown. This is the application name of the module actually started. If symlinks are used then it is the name of the symlinked application.

--shutdown-master-username arg

Sets the name of the master-username of the messaging used for auto-shutdown. If "shutdown-master-module" is given as well this parameter is ignored.


--verbosity arg

Verbosity level [0..4]. 0:quiet, 1:error, 2:warning, 3:info, 4:debug

-v, --v

Increase verbosity level (may be repeated, eg. -vv)

-q, --quiet

Quiet mode: no logging output

--component arg

Limits the logging to a certain component. This option can be given more than once.

-s, --syslog

Use syslog logging back end. The output usually goes to /var/lib/messages.

-l, --lockfile arg

Path to lock file.

--console arg

Send log output to stdout.


Debug mode: --verbosity=4 --console=1

--log-file arg

Use alternative log file.


-u, --user arg

Overrides configuration parameter connection.username.

-H, --host arg

Overrides configuration parameter connection.server.

-t, --timeout arg

Overrides configuration parameter connection.timeout.

-g, --primary-group arg

Overrides configuration parameter connection.primaryGroup.

-S, --subscribe-group arg

A group to subscribe to. This option can be given more than once.

--content-type arg

Overrides configuration parameter connection.contentType.

--start-stop-msg arg

Sets sending of a start- and a stop message.



List all supported database drivers.

-d, --database arg

The database connection string, format: service://user:pwd@host/database. "service" is the name of the database driver which can be queried with "--db-driver-list".

--config-module arg

The configmodule to use.

--inventory-db arg

Load the inventory from the given database or file, format: [service://]location



List all supported record stream drivers

-I, --record-url arg

The recordstream source URL, format: [service://]location[#type]. "service" is the name of the recordstream driver which can be queried with "--record-driver-list". If "service" is not given "file://" is used.

--record-file arg

Specify a file as record source.

--record-type arg

Specify a type for the records being read.



Do not connect to a messaging server and do not use the database.

--end-time arg

Set the acquisition end time, e.g. ‘2017-09-08 13:30:00’, default: ‘gmt’


--stream arg

The record stream that should be displayed: stream=net.sta.loc.cha

--filter arg

The filter to apply

--gain arg

Gain applied to the data before plotting

--amp-scaling arg

Lower bound of amplitude range per row. Possible values:

minmax: Scale all rows to configured minimum and maximum amplitudes.

row: Scale each row to the maximum within this row.

--amp-range-min arg

Lower bound of amplitude range per row

--amp-range-max arg

Upper bound of amplitude range per row

--amp-range arg

Arround zero bound of amplitude range per row

--record-time arg

Does the last row always contain the last record received


--desc arg

Enables/disables the display of a station description

--rows arg

Configures the number of rows to display

--time-span arg

Configures the time-span (in secs) per row. Unit: seconds.

--aa arg

Sets antialiasing for rendering the traces

--xres arg

Output x resolution when generating images. Unit: dpi.

--yres arg

Output y resolution when generating images. Unit: dpi.

--dpi arg

Output dpi when generating postscript. Unit: dpi.

-o arg

Output filename. Placeholders are %N,%S,%L,%C for network code, station code, location code, channel code.

--interval arg

Snapshot interval (less than 0 disables timed snapshots). Unit: seconds.