diff --git a/config/config.yml b/config/config.yml
index 49f3a66..47b6c8b 100644
--- a/config/config.yml
+++ b/config/config.yml
@@ -15,19 +15,19 @@ process:
     overlap: 0
   ambiguity:
     delayMin: -10
-    delayMax: 300
-    dopplerMin: -300
-    dopplerMax: 300
+    delayMax: 400
+    dopplerMin: -200
+    dopplerMax: 200
   clutter:
     delayMin: -10
-    delayMax: 300
+    delayMax: 400
   detection:
     pfa: 0.00001
-    nGuard: 10
-    nTrain: 20
+    nGuard: 2
+    nTrain: 6
     minDelay: 5
     minDoppler: 15
-    nCentroid: 10
+    nCentroid: 6
   tracker:
     initiate:
       M: 3
diff --git a/config/radar4.yml b/config/radar4.yml
index 8cb18c5..47b6c8b 100644
--- a/config/radar4.yml
+++ b/config/radar4.yml
@@ -5,7 +5,7 @@ capture:
     type: "RspDuo"
   replay:
     state: false
-    loop: true  
+    loop: true
     file: '/opt/blah2/replay/file.rspduo'
 
 process:
diff --git a/src/capture/Source.cpp b/src/capture/Source.cpp
index c981572..16bc36c 100644
--- a/src/capture/Source.cpp
+++ b/src/capture/Source.cpp
@@ -20,7 +20,6 @@ Source::Source(std::string _type, uint32_t _fc, uint32_t _fs,
   fs = _fs;
   path = _path;
   saveIq = _saveIq;
-  saveIqFile = NULL;
 }
 
 std::string Source::open_file()
@@ -39,9 +38,9 @@ std::string Source::open_file()
     typeLower.begin(), ::tolower);
   std::string file = path + timestamp + "." + typeLower + ".iq";
 
-  saveIqFile = fopen(file.c_str(), "wb");
+  saveIqFile.open(file, std::ios::binary);
 
-  if (saveIqFile == NULL)
+  if (!saveIqFile.is_open())
   {
     std::cerr << "Error: Can not open file: " << file << std::endl;
     exit(1);
@@ -53,12 +52,12 @@ std::string Source::open_file()
 
 void Source::close_file()
 {
-  if (saveIqFile != NULL)
+  if (!saveIqFile.is_open())
   {
-    fclose(saveIqFile);
-  }
-  else
-  {
-    std::cerr << "Error: Can not close file pointer." << std::endl;
+    saveIqFile.close();
   }
+
+  // switch member with blank file stream
+  std::ofstream blankFile;
+  std::swap(saveIqFile, blankFile);
 }
\ No newline at end of file
diff --git a/src/capture/Source.h b/src/capture/Source.h
index c99b41e..fcd150e 100644
--- a/src/capture/Source.h
+++ b/src/capture/Source.h
@@ -8,6 +8,7 @@
 
 #include <string>
 #include <stdint.h>
+#include <fstream>
 #include "data/IqData.h"
 
 class Source
@@ -29,8 +30,8 @@ protected:
   /// @brief True if IQ data to be saved.
   bool *saveIq;
 
-  /// @brief File pointer to IQ data to be saved.
-  FILE *saveIqFile;
+  /// @brief File stream to save IQ data.
+  std::ofstream saveIqFile;
 
 public:
 
diff --git a/src/capture/rspduo/RspDuo.cpp b/src/capture/rspduo/RspDuo.cpp
index 88ca030..03e4321 100644
--- a/src/capture/rspduo/RspDuo.cpp
+++ b/src/capture/rspduo/RspDuo.cpp
@@ -8,6 +8,7 @@
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>
+#include <fstream>
 #include <iostream>
 
 // class static constants
@@ -36,7 +37,7 @@ sdrplay_api_CallbackFnsT cbFns;
 sdrplay_api_RxChannelParamsT *chParams;
 
 // global variables
-FILE *out_file_fp = NULL;
+//FILE *out_file_fp = NULL;
 FILE *file_replay = NULL;
 short *buffer_16_ar = NULL;
 struct timeval current_tm = {0, 0};
@@ -50,7 +51,8 @@ short max_b_nr = 0;
 bool run_fg = true;
 bool stats_fg = true;
 bool write_fg = true;
-bool capture_fg = false;
+bool *capture_fg;
+std::ofstream* saveIqFileLocal;
 int wait_time_nr = 2;
 IqData *buffer1;
 IqData *buffer2;
@@ -72,8 +74,9 @@ RspDuo::RspDuo(std::string _type, uint32_t _fc, uint32_t _fs,
   dab_notch_fg = false;
   chunk_time_nr = DEF_CHUNK_TIME_NR;
 
-  out_file_fp = saveIqFile;
-  capture_fg = &saveIq;
+  //out_file_fp = saveIqFile;
+  capture_fg = saveIq;
+  saveIqFileLocal = &saveIqFile;
 }
 
 void RspDuo::start()
@@ -526,29 +529,13 @@ void RspDuo::stream_b_callback(short *xi, short *xq, sdrplay_api_StreamCbParamsT
     write_fg = true;
   }
 
-  // init file open
-  // if (capture_fg && write_fg && run_fg && chunk_tm.tv_sec <= current_tm.tv_sec)
-  // {
-  //   if (out_file_fp != NULL)
-  //   {
-  //     fclose(out_file_fp);
-  //   }
-  //   out_file_fp = fopen(file.c_str(), "ab");
-  //   if (out_file_fp == NULL)
-  //   {
-  //     std::cerr << "Error - stream_b_callback - opening output file " + file << std::endl;
-  //     free(buffer_16_ar);
-  //     run_fg = false;
-  //     exit(1);
-  //   }
-
-  //   chunk_tm = current_tm;
-  // }
-
   // write data to file
-  if (capture_fg && write_fg)
+  if (*capture_fg && write_fg)
   {
-    if (fwrite(buffer_16_ar, sizeof(short), numSamples * 4, out_file_fp) != (size_t)numSamples * 4)
+    saveIqFileLocal->write(reinterpret_cast<char*>(buffer_16_ar), 
+      sizeof(short) * numSamples * 4);
+    
+    if (!(*saveIqFileLocal))
     {
       std::cerr << "Error - stream_b_callback - not enough samples received" << std::endl;
       free(buffer_16_ar);
diff --git a/src/capture/usrp/Usrp.cpp b/src/capture/usrp/Usrp.cpp
index 177238f..0422734 100644
--- a/src/capture/usrp/Usrp.cpp
+++ b/src/capture/usrp/Usrp.cpp
@@ -93,9 +93,14 @@ void Usrp::process(IqData *buffer1, IqData *buffer2)
       buffer2->unlock();
 
       // save IQ data to file
-      if (saveIq)
+      if (*saveIq)
       {
-
+        for (const auto& bufferPtr : buff_ptrs) 
+        {
+        // Write the buffer data to the file
+          saveIqFile.write(reinterpret_cast<const char*>(
+            bufferPtr), samps_per_buff * sizeof(std::complex<float>));
+        }
       }
     }
 }