TREMBLE user manual

   
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3 System Setup

This section contains a guide for performing a typical installation of a TREMBLE system. It includes three major steps:

  1. Installing all the hardware that comprises the recording station that detects lightning strikes and records the associated thunder;
  2. installing all the non-visualization software -- that is, the software required to record thunder, analyze the sound and compute lightning positions, create data files to be read later, and maintain a recording schedule; and
  3. installing the visualization program, Crossbow, which allows a user to playback storm files and interactively explore a lightning storm.

3.1 Recording Station Setup

Required hardware for recording station:

Placing of microphones and lightning detector

Choose a location for your microphones and lightning detector. This should be someplace relatively flat and unobstructed such as an open field or the top of a building. Position the microphones in a pattern of a regular polygon (an equilateral triangle for three microphones, a square for four, etc.) If the pattern of an regular polygon isn't possible, place the microphones as far away from collinear as possible. Choose a "center point" inside or near the microphone array; determine its longitude and latitude as accurately as possible. Measure the locations of the microphones with respect to this chosen point; the system works best when the positions of the microphones are known to within one foot. Keep all those measurement handy; you will need them for the software configuration later. Next, attach a pre-amplifier to each microphone. Now, place the lightning detector near or within the microphone array. Its exact position is unimportant. Finally, run cables from the pre-amplifiers and the lightning detector to the PC, then ensure that all components are shielded from the rain or are otherwise waterproofed. It is also a good idea to secure all components the the ground or some other structure, to prevent the high winds common in thunderstorms from blowing them out of position.

microphone array
Figure 1. Example layout of microphone array.

3.2 Installation of Non-visualization Software

The first step in installing the non-visualization software is extracting the files to the correct directories directory. On your PC, run the self-extracting archive file tr_servers.exe. A dialog box will appear asking for a directory where it should place the extracted files; select a directory and the software will be placed in a directory tree under the directory you chose. We'll refer to the directory you chose as the tremble from this point forth.

Configuring the servers

In the tremble/servers subdirectory, there will be four configuration files (acquisition.cfg, analysis.cfg, manager.cfg, and recorder.cfg) and three executable files (acquisition_server.exe, analysis_server.exe, and data_server.exe) which serve as the sound acquisition, sound analysis, and data servers. The four configuration files may need to be edited based on your particular PC or hardware.

Configuration files acquisition.cfg, analysis.cfg, manager.cfg

(Examples of these files are listed after this section.)

In each of these configuration files, the name at the beginning of each line is a type of device used by its corresponding program (acquisition.cfg is for acquisition_server.exe, analysis.cfg is for analysis_server.exe and manager.cfg is for data_server.exe). These device names should not be changed - if they are omitted then that device will not be opened by the program. To the right of each device type name is a specific name and some other options used to configure and identify the device. For vrpn_trLightningDetectorTR there is an optional parameter at the end of the line that specifies the number of the serial port (either 1 or 2) to which the lightning detector is connected. For vrpn_RecorderWaveFile the last parameter is the name of a wave audio file (.wav) relative to the directory containing the executable which will be opened as input to the audio recording simulator (this is a system testing facility that shouldn't need to be used by users unless the user is also a developer). If you wish to use the simulated audio input from a wave file then change the entry in analysis.cfg for vrpn_Recorder_Remote to be audio_fake@thunder1-cs*.

*thunder1-cs is the name of the computer in our setup. If these programs are run on a PC named thunder1-cs, none of these parameters should need to be changed. If these programs are run on another machine, then replace all references to thunder1-cs to the name of the machine.

"acquisition.cfg":
vrpn_trLightningDetectorTR ld0 1
vrpn_RecorderWin32 audio0 test_out
vrpn_RecorderWaveFile audio_fake thunder0.wav

"analysis.cfg":
vrpn_trLightningTracker_Local lt1
vrpn_trLightningDetector_Remote ld0@thunder1-cs
vrpn_Recorder_Remote audio0@thunder1-cs

"manager.cfg":
vrpn_trScheduleManager_Local schedule0
vrpn_trLightningTracker_Local lt0
vrpn_trDataManager_Local data0
vrpn_trLightningTracker_Remote lt1@thunder1-cs
  
Figure 2. Example configuration files acquisition.cfg, analysis.cfg, manager.cfg.
Configuration file recorder.cfg

Also in the tremble/servers directory is recorder.cfg. This configuration file is different from the others in that it refers to the configuration of a vrpn_RecorderWin32 device. The first entry in the file gives the location of the "center point" of the microphone array in longitude and latitude (in decimal degrees) and altitude above sea level(meters). Later entries give information about the locations of the individual microphones relative to the center location in (x,y,z) meters where x is east relative, y is north relative and z is altitude relative. In Windows, each sound device is limited to 2 channels so every line in this file will be of the form:

device_name x_chan0 y_chan0 z_chan0 x_chan1 y_chan1 z_chan1
  
as in the example below. The device name must match exactly the wave input device names returned by the Windows Multimedia API - these are printed to the screen when you start up the acquisition_server.exe program. It is okay to have device entries in the recorder.cfg file that are not for devices on the particular machine you are running on - these will be ignored since the list of available devices is taken directly from Windows.
"recorder.cfg":
base -77.0 34.0 250.0
Sound Blaster Record 20 0 0 0 50 0
... (other device records (e.g. MidiMan DMAN 2044 1/2)
  
Figure 3. Example configuration file recorder.cfg.

Starting the servers

Leave all seven files in the tremble/servers directory. First, start up acquisition_server.exe. You will be presented with a menu from which to select sound input devices. Select the two devices for the MidiMan sound card and then enter the number of the option to exit the menu. The acquisition server is now ready to be connected to the analysis module. Next start up analysis_server.exe. Finally, start up data_server.exe. If there were any error messages other than that a wave file (for simulated audio recording) is missing then there may be a network problem or the configuration files may not be correct (check the machine name).

Setting up the StormTracker web-based scheduler

The two additional files needed for StormTracker, the web-based scheduler, are extracted to tremble/StormTracker when you run servers.exe. StormTracker.html is the web page that you access to view or edit the recording schedule, and StormTracker.cgi is the CGI program that serves as the interface between the web page and the data server. Copy these to the normal places for HTML and CGI files on your web server, and edit the file paths indicated inside those pages to match the locations of your installed files.

3.3 Installation of Crossbow

To install the Crossbow visualization program and the Compass map preprocessor on a UNIX machine, decompress the file tr_viz.tar.gz using gunzip and tar -xvf into a directory you choose. To install Crossbow and Compass onto a PC, simply run the self-extracting file tr_viz.exe and enter the directory in the dialog box where you want the files placed.

To create the maps used by Crossbow, you must obtain maps in one of the USGS standard formats and process them first with the Compass map preprocessor. The Compass preprocessor reduces the complexity of the map information, so that Crossbow can render it at interactive rates and so that your view of lightning in your area remains relatively uncluttered.

The configuration file that goes with Compass, compass.cfg, has several lines that each point to a directory containing certain kinds of maps: topography maps, boundary maps, road maps, hydrography (water) maps, and building maps. An example Compass configuration file is listed below:

"compass.cfg"
topography maps: \\ZETA\baker\145\data\usgs\chapel_hill_area\topography\
road maps: \\ZETA\baker\145\data\usgs\chapel_hill_area\roads\
water maps:
boudary maps: \\ZETA\baker\145\data\usgs\chapel_hill_area\boundaries\
building maps:
  
Figure 4. Example configuration file compass.cfg.

A configuration line is not needed if its corresponding class of map is not used; thus the water maps: and building maps: lines of the file could have been omitted.

After each kind of map, the top-level directory containing each kind of map is listed. Each individual map obtained in your set of maps (i.e. each individual SDTS-DLG, SDTS-DEM, etc.) should be installed in its own subdirectory under the appropriate map directory. For example, given our example configuration file above, if you wanted to use topological and road maps which covered Chapel Hill, southwest Durham, and Hillsborough, those maps would be installed in the following directories:

\\ZETA\baker\145\data\usgs\chapel_hill_area\topography\chapel_hill\
\\ZETA\baker\145\data\usgs\chapel_hill_area\topography\sw_durham\
\\ZETA\baker\145\data\usgs\chapel_hill_area\topography\hillsborough\
\\ZETA\baker\145\data\usgs\chapel_hill_area\roads\chapel_hill\
\\ZETA\baker\145\data\usgs\chapel_hill_area\roads\sw_durham\
\\ZETA\baker\145\data\usgs\chapel_hill_area\roads\hillsborough\
  

After placing your maps in their directories and updating the configuration file, run Compass. The processed map files produced by Compass, will all have the names of the form tr_*.map. If Compass is not moved from its original installation location, those maps will be placed into a subdirectory maps/ of the directory containing the Crossbow executable.


   
Next: 4 Getting Started Previous: 2 Overview

author(s): Eric D. Baker, Adam Seeger, Mave T. Houston
last update: 03 May 1999 11:08p by Eric D. Baker