gis

Gempa Image Server - Tiny Web server for maps, tiles and trace images

Description

GIS is an image server allowing to generate images of various kinds showing event information, maps or waveform data. The images are generated upon request and delivered in all formats supported by Qt: PNG, JPG, JPEG, BMP, PPM, TIFF, XBM, XPM.

• Event information on a map, optionally along with contributing stations,

• Station information on a map,

• Waveform data:

  • time series,

  • Fourier spectra,

  • composite images consisting of any components from above can be generated by GIS or external tools.

The images can be generated interactively on demand or automatically and on demand by other modules, e.g. GDS [1].

Note

The GIS package is automatically provided as a separate package when purchasing GDS [1].

Data Sources

GIS collects data from different sources depending on the requested data type. The source must be configured or the information must be provided:

• Event parameters: Provided by HTTP POST as event XML. This includes:

  • events with preferred origin, magnitude and focal mechanism / moment tensor,

  • origins with arrivals and magnitudes,

  • moment tensors

• Inventory: Read from the SeisComP database or from a provided inventory XML file,

• Waveforms: Read from the configured RecordStream.

  Important

  The RecordStream configuration must not include any real-time source, such as seedlink without a timeout. Use the option ?arch when fetching data from a CAPS server using the caps RecordStream.

  Example configurations:

  • seedlink only with short time out:

    recordstream = slink://localhost:18000?timeout=1&retries=0
    

  • caps only with archive option:

    recordstream = caps://localhost:18002?arch
    

  • seedlink combined with gempa’s router RecordStream. The plugin rsrouter must be loaded

    plugins = ${plugins},rsrouter
    recordstream = combined://slink/localhost:18000?timeout=1&retries=0;router/@SYSTEMCONFIGDIR@/router.conf
    

• Map:

  • Map Tiles - loaded from local tile store or map server,

  • Geo Features - loaded from spatial/vector directory in SYSTEMCONFIGDIR or CONFIGDIR,

  • Geo Features - transmitted as JSON documents via HTTP POST,

  • Geo Images - transmitted via HTTP POST in order of their transmission,

  • Vector Layer - coordinate grid, cities loaed from cities XML file,

  • Screen Images - transmitted via HTTP POST in order of their transmission.

Generating Requests

The GIS supports HTTP-GET and HTTP-POST requests. The detailed keys, values and descriptions are provided by the documentation on the webpage created by the GIS server itself. The website is provided by the GIS server on port 20001 by default. To view the website, start the SeisComP messaging and gis:

seiscomp start scmaster
seiscomp exec gis --debug

Then open the website with the configured port and view the options:

firefox localhost:20001

Figure 1: GIS web page exposed by default on http://localhost:20001.

Sending Requests

Requests can be sent to the GIS server in different ways depending on the request content:

• A custom Python script

• Linux commands like wget or curl

Find some examples in the section Examples.

Examples

Maps may contain event and station information alone or together. Data is shown as time series or Fourier spectra. This section provides examples for generating images interactively on demand.

Map with event and stations

Plot event information from one more events along with stations providing arrivals. The event and station information are provided in a single file event-inventory.xml. Generate this file using scxmlmerge [3] or provide the inventory to gis from the database:

scxmlmerge event.xml inventory.xml > event-inventory.xml
curl -X POST -d @event-inventory.xml "http://localhost:20001/map?&dim=1024,512&stations=*&&reg=-30,180,40,20" -o /tmp/gis-event-map.png

Figure 2: Map with event information, map features and stations providing arrivals.

Multiple events are plotted if contained in the event XML file.

Map with stations

Generate a map of stations. Post the inventory XML file and draw all stations. The file can be created using scxmldump [2]. Example:

scxmldump -d localhost -If -o inventory.xml
curl -X POST -d @inventory.xml "http://localhost:20001/map?&dim=1024,512&reg=0,110,20,10&stations=*" -o /tmp/gis-stations.png

Figure 3: Example of a map with stations from inventory.

Waveform data with arrivals from event

Generate plots of waveforms with arrival information from one event. The posted file event.xml contains the complete event information. The file can be created for an event with ID eventID using scxmldump [2], e.g.:

scxmldump -d localhost -E [eventID] -PAf -o event.xml
curl -X POST -d @event.xml "http://localhost:20001/traces?dim=1024,1024&num=7&fmt=png&buffersize=360&orderby=distance&removeoffset=1&weight=1.0&filter=BW(3,1.0,9.0)&showpicks=true&showtt=true&start=2021-02-03T05:28:00&amprange=10000000&usegain=true" -o /tmp/gis-traces-arrivals.png

Figure 4: Example of a trace plot with arrival information.

While the measured phased arrivals are marked by red symbols, the theoretical times are indicated with blue dots.

Waveform data for a time window

Generate plots of waveforms for a given time range. Apply the gain to show physical units:

wget -O /tmp/gis-traces.png "http://localhost:20001/traces?streams=IU.M*.00.BHZ&dim=1024,700&start=2020-05-01&bufferSize=30000&num=5&usegain=true"

Figure 5: Example of a trace plot.

Fourier spectra for a time window

Generate Fourier spectra from waveform data:

• Amplitude spectra

  wget -O /tmp/gis-spectra.png "http://localhost:20001/spectra?stream=IU.ANMO.00.BHZ&dim=1024,500&start=2020-05-01&mode=phase"
  

  

  Figure 6: Example of a Fourier amplitude spectrum.

• Phase spectra

  wget -O /tmp/gis-spectra-phase.png "http://localhost:20001/spectra?stream=IU.ANMO.00.BHZ&dim=1024,500&start=2020-05-01&mode=phase"
  

  

  Figure 7: Example of a Fourier phase spectrum.

• Power spectra

  wget -O /tmp/gis-spectra-power.png "http://localhost:20001/spectra?stream=IU.ANMO.00.BHZ&dim=1024,500&start=2020-05-01&mode=power"
  

  

  Figure 8: Example of a Fourier power spectrum.

Composite images

GIS can generate composite images consisting of different images generated before.

Module Configuration

etc/defaults/global.cfg

etc/defaults/gis.cfg

etc/global.cfg

etc/gis.cfg

~/.seiscomp/global.cfg

~/.seiscomp/gis.cfg

gis inherits global options.

Note

Modules/plugins may require a license file. The default path to license files is @DATADIR@/licenses/ which can be overridden by global configuration of the parameter gempa.licensePath. Example:

gempa.licensePath = @CONFIGDIR@/licenses

dbDisable

Default: false

Type: boolean

If set to true, no inventory and configuration is fetched from the database. Also no connection attempt to the messaging system is made to retrieve the database parameters.

bind

Default: 127.0.0.1:20001

Type: host-with-port

IP and port to bind the command interface to. Use 0.0.0.0 to bind to all interfaces. Either the port or the IP address may be omitted, e.g. "0.0.0.0" or ":1234". If set to an empty string the application will run without providing a command interface.

rootURL

Type: string

Defines the root URL used to generate links. That option is only important if e.g. Apache with reverse proxy is used to forward GIS webpages.

mediaDirectory

Default: @DATADIR@/gis/media

Type: string

Path to media files (index.html, .css, .js, .ico, …) served by GIS.

accessLog

Default: false

Type: boolean

Enables HTTP access logging to @LOGDIR@/gis-http-access. Logfiles are created for 24h and kept for 7 days using log rotation.

ttt

Default: libtau

Type: string

Name of travel time table interface, e.g. ‘libtau’ or ‘locsat’

ttColors

Type: list:string

List of case sensitive phase name to color mappings, e.g. "P:red,S:#00ff00,PP:#aabbcc". Unmapped phases are not drawn.

ttRadius

Default: 3

Unit: px

Type: double

Radius of the travel time circles

errorImage

Default: false

Type: boolean

If enabled errors will be reported inside an image file. The HTTP status code will be set to ‘200 OK’ in this case.

urlLen

Default: 1024

Type: int

Maximum number of URL characters.

tilesTimeout

Default: 0

Unit: s

Type: double

Timeout in seconds after which the download of tiles should be aborted. On timeout the requested map image is rendered with an incomplete image layer. This option is only used if an asynchronous tile store is configured.

originSymbol

Type: string

Origin symbol image. If defined the image is plotted instead of the standard circle. The size and color still depends on the magnitude and depth.

Command-Line Options

Generic

Verbosity

Server

-p, --port arg

Overrides configuration parameter port.