====================================================================== U. S. Department of the Interior, U. S. Geological Survey check_picks_x: A Program for Checking the Travel Time Picks of Crosswell Seismic and Radar Data Karl J. Ellefsen Open File Report 00-109 URL: http://greenwood.cr.usgs.gov/pub/open-file-reports/ofr-00-0109/ ====================================================================== 1. Overview Program 'check_picks_x' is used to interactively check the travel time picks of crosswell seismic and radar data. The checks are made with various plots of the travel times or quantities calculated from the travel times, the transmitter locations, the receiver locations, and the time statics for the transmitter (if any). The plots include the travel times (or calculated quantities) from all seismic or radar traces collected between two wells The plots are displayed on the computer screen or may be printed to a file using Postscript format. Although the program was written for crosswell data, it is general enough that it may be used for other data like travel times from surface to well data. The program is written in the IDL programming language, and it is executed, in command-line mode, within the IDL program. The program has been tested and found to operate properly on both the Unix and Windows 98 operating systems. This file 'README.TXT' describes (a) The contents and organization of the tape archive file (section 2). (b) Program 'check_picks_x', its installation, its execution, and the format of the input data (section 3). (c) Plots generated from some sample input data (section 4). (d) The address of Reseach Systems, Inc., which distributes IDL (section 5). This file does not describe the interpretation of the plots generated by program 'check_picks_x'. If you find any errors or if you have any suggestions for improving the program, please contact: Karl J. Ellefsen U. S. Geological Survey MS 964, Box 25046 Denver, CO 80225 telephone: 303-236-7032 email: ellefsen@usgs.gov ====================================================================== 2. Contents and Organization of the Tape Archive File The name of the tape archive file (tar file) is 'check_picks_x.TAR', and its contents can be viewed with the Unix command: 'tar tvf check_picks_x.TAR'. In the top level of the tar file is 'README.TXT' --- a copy of this text file. The tar file also contains two directories. In directory 'check_picks_x' are 7 files needed to execute the program. All 7 files are described in section 3.1. In directory 'test_data' are 14 files. Of these 14 files, 4 are input data to program 'check_picks_x' and are described in section 3.3. The remaining 10 files contain Postscript plots and were generated by program 'check_picks_x'; these files are described in section 4. ====================================================================== 3. Program 'check_picks_x' 3.1 Program files In the directory 'check_picks_x' are 7 different files that are needed to run program 'check_picks_x': File Name Short Description ----------------- ----------------------------------------------- check_picks_x.pro Controls the main menu. read_data.pro Reads the file with the travel times, the file with the transmitter locations, the file with the receiver locations, and the file with the time statics for the transmitter (if it exists). calculate.pro Calculates various quantities (like average velocity along a ray) that are needed for the plots. check_wid.pro Controls the menu for the plots. plot_check.pro Creates various plots that are displayed on the computer screen. The plots may be printed in a file (using Postscript format). resize_win.pro Resizes the graphics (drawing) window. Help Contains information about the various options in program 'check_picks_x'. This file is ASCII text, and so it may be readily printed. (Sometimes, users find that a printed copy of program instructions and other 'help' information is better than reading the same information on the computer screen.) ---------------------------------------------------------------------- 3.2 Installation The installation requires four steps: 1. Copy the tar file to a suitable directory on the Unix computer. Extract the contents of the tar file using the command: 'tar xf check_picks_x.TAR'. Make the current directory 'check_picks_x'. 2. Load procedure 'check_picks_x.pro' into an editor and go to line 191. Line 191 and the next 11 lines are: ; Initialization of variables that are used in all procedures. ; These five variables may require modification for different ; data sets and different installations of the code. MAX_BIN ; should equal roughly the square root of MAX_TT. MAX_TT = 2000L MAX_TX = 100L MAX_RX = 2000L MAX_BIN = 45L pgm_dir = '/musette/u/ellefsen/seismic/process/check_picks_x/' Variable 'MAX_TT' is the maximum number of travel times; variable 'MAX_TX' is the maximum number of transmitter locations; variable 'MAX_RX' is the maximum number of receiver locations; and variable 'MAX_BIN' is the maximum number of bins in the histogram of reduced travel times. The values shown above are large enough for most data sets encountered in practice. In some rare cases, however, even larger values might needed. If the values are changed, be sure to append an 'L' to the number. (The 'L' indicates that the number is a long integer.) Variable 'pgm_dir' is the directory with the files needed to run program 'check_picks_x'. This variable is used, during execution, to set the path when the program is run on the Unix operating system. When changing this variable, be sure to include the slashes '/' at the beginning and the end. For the Windows operating system, set the path using the IDL menu. ---------------------------------------------------------------------- 3.3 Input Data The formats for the input data are explained using the files in the directory 'test_data' as examples. 3.3.1 File with the Travel Times Examine file 'test_data/travel_times'. This file has four columns: 38 59 1.68e-07 1.00 38 62 1.898e-07 1.00 38 65 2.116e-07 0.50 38 68 2.318e-07 0.25 ... In the first and the second columns are the transmitter and the receiver indentification numbers, respectively. Both numbers must be integers. In the third column is the travel time (in seconds), and in the fourth column is the weight. (A weight of 1.00, 0.50, or 0.25 indicates that the travel time is reliable, somewhat reliable, or somewhat unreliable, respectively. These weights are used during an inversion for the velocity.) For each travel time, there must be a transmitter location and a receiver location. ---------------------------------------------------------------------- 3.3.2 File with the Transmitter Locations Examine file 'test_data/tx_loc'. This file has four columns: 38 0.203962 -0.255706 40.680000 41 0.216522 -0.207316 43.680000 44 0.229088 -0.158921 46.680000 47 0.233839 -0.116755 49.680000 ... In column 1 is the transmitter identification number; this number must be an integer. In columns 2, 3, and 4 are the Cartesian coordinates of the transmitter --- that is, these three numbers are the x, y, and z coordinates, respectively. These particular coordinates are in meters, although any units may be used. 3.3.3 File with the Receiver Locations Examine file 'test_data/rx_loc'. This file has four columns: 23 13.036440 -0.483750 24.629999 26 13.044253 -0.477518 27.629999 29 13.052073 -0.471281 30.629999 32 13.066130 -0.472864 33.630001 ... In column 1 is the receiver identification number; this number must be an integer. In columns 2, 3, and 4 are the Cartesian coordinates of the receiver --- that is, these three numbers are the x, y, and z coordinates, respectively. These particular coordinates are in meters, although any units may be used. 3.3.4 File with the Time Statics of the Transmitter Examine file 'test_data/initial_statics'. This file has three columns: 38 -23.0e-09 1.25e+08 41 -26.5e-09 1.24e+08 44 -22.3e-09 1.25e+08 47 -24.6e-09 1.24e+08 In column 1 is the transmitter identification number; this number must be an integer. In column 2 is the time static for the transmitter (in seconds). In column 3 is the velocity associated with the time static. (The unit for this particular velocity is m/s. The unit used for length must be identical to the unit used for the coordinate system. This velocity is calculated from a common source (transmitter) gather assuming that the medium between the transmitter and the receivers is homogeneous.) For each time static, there must be a transmitter location. For some data sets, times statics for the transmitter do not exist. Program 'check_picks_x' will operate properly without these statics. ---------------------------------------------------------------------- 3.4 Execution 1. Make the current directory that in which the data are stored. Check the shell environment to be sure that the display argument is set to the current X-window terminal. 2. Type 'idl', to load the IDL program. 3. At the prompt 'IDL>', type '.compile XXX/check_picks_x' where XXX is the directory in which 'check_picks_x.pro' is located. 4. If the X-window terminal is actually a PC running an X-window emulation program and if the color system is 'true color', then, the command 'device,decompose=0' causes IDL to send the proper color index values to the PC. For more information, see Reference Guide, vol. 1 (1998, p. 98). 5. At the prompt 'IDL>', type 'check_picks_x' to begin execution. The look and feel of the program is similar to that of most windows programs, and so most users will readily figure out how the progam works. If a question arises, users can get an answer in the 'Help' documentation, which is loaded when the 'Help' button is pressed. Each option within program 'check_picks_x' causes one or more windows to appear on the X-windows terminal. The locations at which these windows appear are determined by the software controlling the terminal. Thus, these locations vary. When two or more windows appear, one window may be partially obscured by another. This problem can be easily fixed by moving the windows. 6. To exit from program 'check_picks_x', select the button 'File' on the main menu and then select the button 'Exit' on the submenu. At the prompt 'IDL>', type 'exit'. ====================================================================== 4. Test Data In directory 'test_data' are 14 files, which may be used to test whether program 'check_picks_x' is properly installed. Of these 14 files, 4 are input data to the program and are described in section 3.3. The remaining 10 files are plots generated with the program; they are described in this section. Program 'check_picks_x' was started, the input data were read, and calculations on the input data were performed. For these calculations, the travel times were scaled by 1.e-9; the default velocity (1.20506e+8) was used to calculate the reduced travel times; the reduced travel times were scaled by 1.e-9, which was the sample rate; and the bin size (for the histogram) was chosen to be 1. The data were plotted using the submenus under the button 'Plot', and the plots were stored as Postscript files: Plotted Quantities File name ---------------------------------------- --------- Transmitter Static and Transmitter Depth tx_static.ps Static Velocity and Transmitter Depth static_vel.ps Travel Time and Distance tt_d.ps Velocity and Distance vel_d.ps Velocity and Take-off Angle vel_a.ps Travel Time and Receiver Depth tt_rxd.ps Travel Time and Transmitter Depth tt_txd.ps Histogram of Reduced Travel Times histo.ps Reduced Travel Times rtt.ps Rays, Transmitter and Receiver Locations rays.ps These Postscript files should be identical to the files that you create. ====================================================================== 5. IDL IDL (Interactive Data Language) is designed especially for interactive visualization of scientific and technical data. To execute program 'check_picks_x', IDL (version 5.0 or higher for Unix operating systems) must be installed. IDL is not supplied in this tar file; it may be purchased from Research Systems, Inc. 4990 East Pearl Circle Boulder, Colorado 80301 Telephone: 303.786.9900 Email: info@rsinc.com Internet: http://www.rsinc.com ====================================================================== 6. Disclaimer This open-file report was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof nor any of their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Although all data and software in this open-file report have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and (or) the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data, software, or related materials. ====================================================================== 7. Acknowledgements The ideas for some plots were taken from Majer and others (1990, p. 58-61) and from Pratt and others (1993). This work was supported by the Geophysical Research Project, which is sponsored by the U. S. Geological Survey. ====================================================================== 8. References Majer, E. L., Long, J. C. S., Myer, L. R., Martel, S. J., Peterson, J. E., Jr., Blumling, P., Karasaki, K., and Vomvoris, S., 1990, Joint seismic, hydrogeological and geomechanical investigations of a fractured zone in the Grimsel Rock Laboratory, Switzerland, National Cooperative for the Disposal of Radioactive Waste, Technical Report 90-49, 170 p. Pratt, R. G., McGaughey, W. J., and Chapman, C. H., 1993, Anisotropic velocity tomography: A case study in a near-surface rock mass: Geophysics, v. 58, no. 12, p. 1748-1763. Reference Guide, vol 1., IDL version 5.1, 1998 edition, Boulder, Colorado: Research Systems, Inc., 739 p. ======================================================================