ngl2caps

NGL CAPS plugin. Reads GNSS data in kenv format and sends it to CAPS.

Description

Read GNSS data in kenv format, convert to RAW and send to a CAPS server.

Waveform Data

Format describtions

  • kenv Format: Final 5 min rapid solutions from stations [stat]: http://geodesy.unr.edu/gps_timeseries/rapids_5min/kenv/[stat]/

    • Sample rate: 1/300 sps

    • Example: http://geodesy.unr.edu/gps_timeseries/rapids_5min/kenv/0ALM/

    • Format (http://geodesy.unr.edu/gps_timeseries/README_kenv.txt):

      ----------------------------------------
.kenv format (east,north,up time series)
----------------------------------------
Note: first line of .kenv contains header fields to help human interpretation.

Column  Header          Example     Description
------  -----------     ---------   ------------------------------------
 1      site            JPLM        4-character station ID
 2      sec-J2000       3705278100  GPS seconds since 2000-01-01 12:00:00
 3      __MJD           55833       Modified Julian Day for GPS day
 4      year            2011        Year
 5      mm               9          Month
 6      dd              29          Day of month
 7      doy             272         Day of year
 8      s-day          10800        Seconds of the GPS day
 9      ___e-ref(m)    -0.202261    East from reference longitude in llh
10      ___n-ref(m)     0.079096    North from reference latitude in llh
11      ___v-ref(m)    -0.025883    Up from reference height in llh
12      _e-mean(m)     -0.015904    East from daily mean position
13      _n-mean(m)     -0.000944    North from daily mean position
14      _v-mean(m)      0.000232    Up from daily mean position
15      sig_e(m)       0.005700     Sigma east
16      sig_n(m)       0.006875     Sigma north
17      sig_v(m)       0.021739     Sigma up

  • RINEX data web server: http://geodesy.unr.edu/magnet/rinex/

Data sources

kenv data are provided by Nevada Geodetic Laboratory, NGL (http://geodesy.unr.edu/):

Fetch data

Note

Data on the NGL server are zipped files, one file per year. Geoffrey Blewitt why this is:

“We zip into yearly files which are updated every week. The actual day it is updated varies depending on when other necessary inputs are ready, such as JPL orbit files, and weather model files from TU Vienna, and ocean loading files from Chalmers, Sweden. So, you would not want to check every day, but I would say every Wednesday would typically work. It’s also important to note that while we process Final data every week, often we include newly discovered or late data that can go as far back as 1994. So, we are not just incrementing with a new week of files.

On the technical side, we zip the data into yearly files to reduce the number of “inodes” (files) on our server, which can slow things down when attempting to seek files, and in the past has overloaded the server with maximum number of inodes.

Zipping files has speeded up our operations considerably and allows us to process all the world’s GPS geodetic data (currently > 18,000 stations). It also allows for efficient backup, which can take far too long with individual files.”

For fetching data from the server above adjust:

  • year year to consider as set in the file name. Use “” for all.

  • url

  • outPut: target directory of fetched files

in the Python script provided with the source code: ngl/plugin/tools/fetchFilesFromWeb.py and use it:

python fetchFilesFromWeb.py

Change to the target directory and unpack the files:

cd [target]
unzip *
gunzip *

Running ngl2caps converts data to RAW and sends them to the CAPS server. The assumed physical unit of the output data is nanometer and the original data are assumed in units of meter. The conversion is applied by the gain which is therefore 1000,000,000 by default. Make sure to generate the inventory with the correct gain and gainUnit. If data are stored in “nm” and gainUnit of the stream in the inventory is “m” (SI unit), the gain in the inventory must be 10^{-09}. Example:

ngl2caps --debug -p [target directory] --gain 1000000000

Output streams

The plugin writes the following parameter to the header of the output data.

group

parameter

added

value/remark

network

code

x

from input parameter

network

start time

x

from input parameter

station

code

x

from input file

station

start time

x

same as network

station

coordinates

x

from input file

sensor location

code

x

from input parameter

sensor location

start

x

same as network

sensor location

elevation

x

same as station

stream

code

x

from band + [XYZ][ZNE]

from band + [X][ZNE] : derived data, daily mean removed

from band + [Y][ZNE] : raw data

from band + [Z][ZNE] : sigma data

Inventory

table2inv can be used for conversion of a station table to SCML.

Module Configuration

etc/defaults/global.cfg
etc/defaults/ngl2caps.cfg
etc/global.cfg
etc/ngl2caps.cfg
~/.seiscomp/global.cfg
~/.seiscomp/ngl2caps.cfg

ngl2caps 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

Note

input.* Parameters controlling the input of event information and reception of GNSS data.

input.readFrom

Type: string

Read input data from this file.

input.directory

Type: string

Watch this directory for incoming input files.

input.watchEvents

Default: close_write

Type: string

Listen for specific inotify event(s). If ommitted, close_write events are listened for. Events:

access - file or directory contents were read,

modify - file or directory contents were written,

attrib - file or directory attributes changed,

close_write - file or directory closed, after being opened in writable mode,

close_nowrite - file or directory closed, after being opened in read-only mode,

close - file or directory closed, regardless of read/write mode,

open - file or directory opened,

moved_to - file or directory moved to watched directory,

moved_from - file or directory moved from watched directory,

move - file or directory moved to or from watched directory,

create - file or directory created within watched directory,

delete - file or directory deleted within watched directory,

delete_self - file or directory was deleted,

unmount - file system containing file or directory unmounted.

input.watchPattern

Type: string

Process any events whose filename matches the specified regular expression

input.leapSecondsFile

Default: @DATADIR@/caps/plugins/ngl2caps/leapseconds.txt

Type: string

Name of file with leap seconds.

Note

streams.* Parameters controlling the processing of received data.

streams.networkCode

Default: NG

Type: string

Network code to use.

streams.locationCode

Type: string

Location code to use.

streams.bandCode

Default: U

Type: string

Band code of streams to use. Streams will be formed as [band][sensor type][component].

Note

output.* Parameters controlling the output of received data.

output.host

Default: localhost

Type: string

Data output host.

output.port

Default: 18003

Type: int

Data output port.

output.bufferSize

Default: 1048576

Type: uint

Size (bytes) of the packet buffer.

output.gain

Default: 1000000

Type: float

Apply given gain to samples.

Command-Line Options

Generic

-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. Example: scautopick -> scautopick2.

Verbosity

--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.

--print-component arg

For each log entry print the component right after the log level. By default the component output is enabled for file output but disabled for console output.

--component arg

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

-s, --syslog

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

-l, --lockfile arg

Path to lock file.

--console arg

Send log output to stdout.

--debug

Execute in debug mode. Equivalent to --verbosity=4 --console=1 .

--trace

Execute in trace mode. Equivalent to --verbosity=4 --console=1 --print-component=1 --print-context=1 .

--log-file arg

Use alternative log file.

Input event

-d, --directory arg

Watch this directory for incoming event input files. By default the current directory is watched.

--watch-pattern arg

Process any event file which file name matches the specified regular expression.

Input waveforms

-f, --file arg

Read kenv data directly from this given file.

-p, --read-from arg

Read all kenv files from this directory path. Only considered if file is not given.

-l, --leap-file arg

Path to leap seconds file.

Filter

Streams

--network-code arg

Network code to use.

--location-code arg

Sensor location code to use.

--location-code arg

Band code to use. Streams will be formed as [band code][xyz][ZNE].

Output

-H, --host arg

Data output host.

-P, --port arg

Data output port.

-g, --gain arg

Gain value multiplied to the data for unit conversion to nm.

-u, --gain-unit arg

Gain unit to write to data file.