diff --git a/bapsflib/lapd/tools/bdot.py b/bapsflib/lapd/tools/bdot.py
new file mode 100644
index 00000000..ec6532a4
--- /dev/null
+++ b/bapsflib/lapd/tools/bdot.py
@@ -0,0 +1,167 @@
+#!/usr/bin/env python3
+import argparse
+import matplotlib.pyplot as plt
+import numpy as np
+import os
+
+# =========================
+# Configuration
+# =========================
+
+# Suffixes for all 9 combinations
+SUFFIXES = ["BXPX", "BXPY", "BXPZ", "BYPX", "BYPY", "BYPZ", "BZPX", "BZPY", "BZPZ"]
+
+# =========================
+# Data loading
+# =========================
+
+
+def load_csv(filename):
+    """
+    Loads an E5100A-style CSV file, stripping quotes and skipping non-numeric header lines.
+    Returns: freq, mag, phase (all numpy arrays)
+    """
+    data_lines = []
+    if not os.path.exists(filename):
+        print(f"WARNING: File {filename} not found. Skipping.")
+        return None, None, None
+
+    with open(filename, "r") as f:
+        for line in f:
+            line = line.strip().strip('"')
+            if line == "":
+                continue
+            if not line[0].isdigit() and not line[0] == "-":
+                continue
+            parts = line.split("\t") if "\t" in line else line.split(",")
+            try:
+                parts = [float(p) for p in parts]
+                data_lines.append(parts)
+            except ValueError:
+                continue
+
+    data = np.array(data_lines)
+    freq = data[:, 0]
+    mag = data[:, 1]
+    phase = data[:, 2]
+
+    return freq, mag, phase
+
+
+# =========================
+# Effective Area Calculation
+# =========================
+
+
+def calculate_effective_area_per_point(freq, mag):
+    """
+    Computes effective area point-by-point using physics formula:
+    Ae(f) = (mag * 0.55) / (0.00180765 * freq)
+    """
+    Ae = (mag * 0.55) / (0.00180765 * freq)
+    return Ae
+
+
+def calculate_effective_area_linear_fit(freq, mag):
+    """
+    Linear fit of magnitude vs frequency for single-value Ae.
+    """
+    slope, intercept = np.polyfit(freq, mag, 1)
+    Ae_single = slope * 307.1389  # calibration factor
+    return Ae_single, slope, intercept
+
+
+# =========================
+# Plotting and Saving
+# =========================
+
+
+def save_plots_and_effective_area(freq, mag, phase, Ae, file_basename, output_dir):
+    """
+    Saves magnitude+effective area and phase plots as PNG,
+    and saves effective area array to CSV.
+    """
+    # Ensure output directory exists
+    os.makedirs(output_dir, exist_ok=True)
+
+    # Dual-axis plot: Magnitude & Effective Area
+    fig, ax1 = plt.subplots(figsize=(10, 5))
+    ax1.plot(freq, mag, "b-", label="Magnitude")
+    ax1.set_xlabel("Frequency (Hz)")
+    ax1.set_ylabel("Magnitude (linear)", color="b")
+    ax1.tick_params(axis="y", labelcolor="b")
+    ax1.grid(True)
+
+    ax2 = ax1.twinx()
+    ax2.plot(freq, Ae, "g-", label="Effective Area")
+    ax2.set_ylabel("Effective Area", color="g")
+    ax2.tick_params(axis="y", labelcolor="g")
+
+    plt.title(f"{file_basename}: Magnitude & Effective Area vs Frequency")
+    fig.tight_layout()
+    mag_ae_file = os.path.join(output_dir, f"{file_basename}_mag_ae.png")
+    plt.savefig(mag_ae_file)
+    plt.close(fig)
+
+    # Phase plot
+    plt.figure(figsize=(10, 4))
+    plt.plot(freq, phase, color="orange")
+    plt.xlabel("Frequency (Hz)")
+    plt.ylabel("Phase (degrees)")
+    plt.title(f"{file_basename}: Phase vs Frequency")
+    plt.grid(True)
+    phase_file = os.path.join(output_dir, f"{file_basename}_phase.png")
+    plt.savefig(phase_file)
+    plt.close()
+
+    # Save effective area array to CSV
+    ae_file = os.path.join(output_dir, f"{file_basename}_Ae.csv")
+    np.savetxt(
+        ae_file,
+        np.column_stack((freq, Ae)),
+        delimiter=",",
+        header="Frequency,EffectiveArea",
+        comments="",
+    )
+
+
+# =========================
+# Main function
+# =========================
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Process E5100A CSV files by target prefix."
+    )
+    parser.add_argument("target", type=str, help="Target prefix (e.g., C19)")
+    args = parser.parse_args()
+
+    target = args.target.upper()  # Ensure uppercase
+    output_dir = f"{target}_results"
+
+    # Generate all 9 possible filenames
+    filenames = [f"{target}{suffix}.csv" for suffix in SUFFIXES]
+
+    for file in filenames:
+        file_basename = os.path.splitext(os.path.basename(file))[0]
+        print(f"Processing {file}...")
+        freq, mag, phase = load_csv(file)
+        if freq is None:
+            continue
+
+        # Compute effective area
+        Ae = calculate_effective_area_per_point(freq, mag)
+        Ae_single, slope, intercept = calculate_effective_area_linear_fit(freq, mag)
+
+        # Print fitted single-value effective area
+        print(f"{file_basename} Fitted Effective Area: {Ae_single:.6f}")
+
+        # Save plots and Ae array
+        save_plots_and_effective_area(freq, mag, phase, Ae, file_basename, output_dir)
+
+    print(f"\nAll processed files saved in folder: {output_dir}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/requirements/install.txt b/requirements/install.txt
index a54aa973..2d3f042d 100644
--- a/requirements/install.txt
+++ b/requirements/install.txt
@@ -6,3 +6,4 @@ bapsf_motion >= 0.2
 h5py >= 3.0
 numpy >= 1.20
 scipy >= 0.19
+matplotlib
diff --git a/setup.cfg b/setup.cfg
index 5946c9bf..7fcc2396 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -46,7 +46,7 @@ install_requires =
     h5py >= 3.0
     numpy >= 1.20
     scipy >= 0.19
-
+    matplotlib
 [options.extras_require]
 extras =
     # ought to mirror requirements/extras.txt