How to Use SeisImager Pickwin v3.14 with Plotrefa v2.73 for Refraction Seismic Data Processing
SeisImager Pickwin is a software package that allows you to perform refraction seismic data processing and interpretation on your PC or Geometrics seismograph. It can handle both P-wave and S-wave data, and it can generate 2D models of the subsurface velocity structure and depth to bedrock. Plotrefa is a companion software that allows you to plot and print your results in various formats.
In this article, we will show you how to use SeisImager Pickwin v3.14 with Plotrefa v2.73 for refraction seismic data processing. We will assume that you have already acquired your data using a Geometrics seismograph and transferred it to your PC. We will also assume that you have installed SeisImager Pickwin and Plotrefa on your PC.
Step 1: Import your data into SeisImager Pickwin
To import your data into SeisImager Pickwin, launch the software and click on File > Import Data. You can choose from various data formats, such as SEG-2, SEG-Y, SEGY-Rev1, SEGD, SPS, SU, ASCII, etc. You can also import data from other software packages, such as RadExPro, ReflexW, WinSeis, etc.
SeisImager Pickwin v3.14 with Plotrefa v2.73 | tested
After selecting your data format, browse to the folder where your data files are located and select them. You can import multiple files at once by holding down the Ctrl key while clicking on them. Click on Open to import the files.
You will see a list of imported files in the Data Files window. You can view the details of each file by clicking on it. You can also edit the file name, shot point number, receiver spacing, etc. by double-clicking on the corresponding fields.
Step 2: Pick first arrivals and assign layer velocities
To pick first arrivals and assign layer velocities, click on the Pick button in the toolbar. You will see a window with a plot of your first file. You can zoom in and out by using the mouse wheel or the + and - buttons. You can also pan by clicking and dragging on the plot.
To pick first arrivals, click on the Pick button in the toolbar again. You will see a crosshair cursor on the plot. Move the cursor to the first arrival of each trace and click on it. A red dot will appear to mark your pick. You can also use the arrow keys to move the cursor and the spacebar to pick.
To assign layer velocities, click on the Layer button in the toolbar. You will see a window with a table of layer parameters. You can enter the velocity and thickness of each layer manually or use the Auto button to automatically assign them based on your picks. You can also use the Edit button to modify or delete existing layers.
After picking first arrivals and assigning layer velocities for your first file, you can repeat the same steps for your other files by using the Next and Previous buttons in the toolbar.
Step 3: Generate 2D models and depth profiles
To generate 2D models and depth profiles, click on the Model button in the toolbar. You will see a window with a plot of your first file with a 2D model overlayed on it. You can adjust the model parameters by using the sliders or typing in the boxes below them.
You can also use the Invert button to automatically invert your picks and generate an optimal model that fits your data. You can choose from various inversion methods, such as GRM (generalized reciprocal method), TOMO (tomographic inversion), or LMA (layered model approximation).
To generate depth profiles, click on the Profile button in the toolbar. You will see a window with a plot of your first file with a depth profile overlayed on it. You can adjust the profile parameters by using the sliders or typing in the boxes below them.
You can also use the Auto button to automatically generate a depth profile that matches your model. You can choose from various methods, such as 0efd9a6b88