diff --git a/CMakeLists.txt b/CMakeLists.txt
index 43d761f55..531554b52 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -970,11 +970,23 @@ if(NOT VOLKGNSSSDR_FOUND)
     else()
         set(VOLK_GNSSSDR_COMPILER -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER} -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER})
     endif()
+
+    find_package(ORC)
+    set_package_properties(ORC PROPERTIES
+        PURPOSE "Used by volk_gnsssdr."
+        TYPE OPTIONAL
+    )
+    if(ORC_FOUND)
+        set(ORC_ENABLED ON)
+    else()
+        set(ORC_ENABLED OFF)
+    endif()
+
     set(VOLK_GNSSSDR_CMAKE_ARGS ${VOLK_GNSSSDR_COMPILER}
         -DCMAKE_INSTALL_PREFIX=${CMAKE_CURRENT_BINARY_DIR}/volk_gnsssdr_module/install
         -DENABLE_STATIC_LIBS=ON
         -DENABLE_PROFILING=${ENABLE_PROFILING}
-        -DENABLE_ORC=OFF
+        -DENABLE_ORC=${ORC_ENABLED}
         ${STRIP_VOLK_GNSSSDR_PROFILE}
         ${USE_THIS_PYTHON}
     )
@@ -1017,11 +1029,6 @@ if(NOT VOLKGNSSSDR_FOUND)
             INSTALL_DIR ${CMAKE_CURRENT_BINARY_DIR}/volk_gnsssdr_module/install
         )
     endif()
-    find_package(ORC)
-    set_package_properties(ORC PROPERTIES
-        PURPOSE "Used by volk_gnsssdr."
-        TYPE OPTIONAL
-    )
 
     if(NOT ORC_FOUND)
         set(ORC_LIBRARIES "")
diff --git a/README.md b/README.md
index 89ad37e84..b8da612c0 100644
--- a/README.md
+++ b/README.md
@@ -160,13 +160,13 @@ This option is adequate if you are interested in development, in working with th
 First of all, install some basic packages:
 
 ~~~~~~
-$ sudo apt-get install git python-pip
+$ sudo apt-get install git python3-pip
 ~~~~~~
 
 Download, build and install PyBOMBS:
 
 ~~~~~~
-$ sudo pip install git+https://github.com/gnuradio/pybombs.git
+$ sudo pip3 install --upgrade git+https://github.com/gnuradio/pybombs.git
 ~~~~~~
 
 Apply a configuration:
@@ -302,9 +302,9 @@ $ sudo apt-get install autoconf automake libtool curl make g++ unzip
 and then:
 
 ~~~~~~
-$ wget https://github.com/protocolbuffers/protobuf/releases/download/v3.10.0/protobuf-cpp-3.10.0.tar.gz
-$ tar xvfz protobuf-cpp-3.10.0.tar.gz
-$ cd protobuf-3.10.0
+$ wget https://github.com/protocolbuffers/protobuf/releases/download/v3.10.1/protobuf-cpp-3.10.1.tar.gz
+$ tar xvfz protobuf-cpp-3.10.1.tar.gz
+$ cd protobuf-3.10.1
 $ ./autogen.sh
 $ ./configure
 $ make
diff --git a/cmake/Modules/FindORC.cmake b/cmake/Modules/FindORC.cmake
index d2b98969f..a170a3038 100644
--- a/cmake/Modules/FindORC.cmake
+++ b/cmake/Modules/FindORC.cmake
@@ -38,8 +38,9 @@ find_path(ORC_INCLUDE_DIR
     PATHS /usr/include
           /usr/local/include
           /opt/local/include
-          ${ORC_ROOT}/include/orc-0.4
-          ${CMAKE_INSTALL_PREFIX}/include/orc-0.4
+          ${ORC_ROOT}/include
+          ${CMAKE_INSTALL_PREFIX}/include
+    PATH_SUFFIXES orc-0.4
 )
 
 find_path(ORC_LIBRARY_DIR
diff --git a/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/cmake/Modules/FindORC.cmake b/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/cmake/Modules/FindORC.cmake
index aa9f0ada9..5c6ad9e06 100644
--- a/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/cmake/Modules/FindORC.cmake
+++ b/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/cmake/Modules/FindORC.cmake
@@ -16,45 +16,62 @@
 # along with GNSS-SDR. If not, see <https://www.gnu.org/licenses/>.
 
 
-find_package(PkgConfig)
+set(PKG_CONFIG_USE_CMAKE_PREFIX_PATH TRUE)
+include(FindPkgConfig)
 pkg_check_modules(PC_ORC "orc-0.4 > 0.4.22")
 
 find_program(ORCC_EXECUTABLE orcc
     HINTS ${PC_ORC_TOOLSDIR}
-    PATHS ${ORC_ROOT}/bin ${CMAKE_INSTALL_PREFIX}/bin
+    PATHS /usr/bin
+          /usr/local/bin
+          /opt/local/bin
+          ${ORC_ROOT}/bin
+          ${CMAKE_INSTALL_PREFIX}/bin
 )
 
-find_path(ORC_INCLUDE_DIR NAMES orc/orc.h
+find_path(ORC_INCLUDE_DIR
+    NAMES orc/orc.h
     HINTS ${PC_ORC_INCLUDEDIR}
-    PATHS ${ORC_ROOT}/include/orc-0.4 ${CMAKE_INSTALL_PREFIX}/include/orc-0.4
+    PATHS /usr/include
+          /usr/local/include
+          /opt/local/include
+          ${ORC_ROOT}/include
+          ${CMAKE_INSTALL_PREFIX}/include
+    PATH_SUFFIXES orc-0.4
 )
 
-
 find_path(ORC_LIBRARY_DIR
     NAMES ${CMAKE_SHARED_LIBRARY_PREFIX}orc-0.4${CMAKE_SHARED_LIBRARY_SUFFIX}
     HINTS ${PC_ORC_LIBDIR}
-        /usr/local/lib
-        /usr/lib/x86_64-linux-gnu
-        /usr/lib/i386-linux-gnu
-        /usr/lib/arm-linux-gnueabihf
-        /usr/lib/arm-linux-gnueabi
-        /usr/lib/aarch64-linux-gnu
-        /usr/lib/mipsel-linux-gnu
-        /usr/lib/mips-linux-gnu
-        /usr/lib/mips64el-linux-gnuabi64
-        /usr/lib/powerpc-linux-gnu
-        /usr/lib/powerpc64-linux-gnu
-        /usr/lib/powerpc64le-linux-gnu
-        /usr/lib/hppa-linux-gnu
-        /usr/lib/s390x-linux-gnu
-        /usr/lib64
-        /usr/lib
-    PATHS ${ORC_ROOT}/lib${LIB_SUFFIX} ${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX}
+    PATHS /usr/lib
+          /usr/lib64
+          /usr/lib/x86_64-linux-gnu
+          /usr/lib/i386-linux-gnu
+          /usr/lib/arm-linux-gnueabihf
+          /usr/lib/arm-linux-gnueabi
+          /usr/lib/aarch64-linux-gnu
+          /usr/lib/mipsel-linux-gnu
+          /usr/lib/mips-linux-gnu
+          /usr/lib/mips64el-linux-gnuabi64
+          /usr/lib/powerpc-linux-gnu
+          /usr/lib/powerpc64-linux-gnu
+          /usr/lib/powerpc64le-linux-gnu
+          /usr/lib/hppa-linux-gnu
+          /usr/lib/s390x-linux-gnu
+          /usr/local/lib
+          /usr/local/lib64
+          /opt/local/lib
+          ${ORC_ROOT}/lib
+          $ENV{ORC_ROOT}/lib
+          ${ORC_ROOT}/lib${LIB_SUFFIX}
+          ${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX}
 )
 
 find_library(ORC_LIB orc-0.4
     HINTS ${PC_ORC_LIBRARY_DIRS}
-    PATHS ${ORC_ROOT}/lib${LIB_SUFFIX} ${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX})
+    PATHS ${ORC_ROOT}/lib${LIB_SUFFIX}
+          ${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX}
+)
 
 list(APPEND ORC_LIBRARY
     ${ORC_LIB}
diff --git a/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/cmake/Modules/VolkPython.cmake b/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/cmake/Modules/VolkPython.cmake
index b67a3c1bb..0f9b353e1 100644
--- a/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/cmake/Modules/VolkPython.cmake
+++ b/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/cmake/Modules/VolkPython.cmake
@@ -133,7 +133,7 @@ file(TO_CMAKE_PATH ${VOLK_PYTHON_DIR} VOLK_PYTHON_DIR)
 function(VOLK_UNIQUE_TARGET desc)
     file(RELATIVE_PATH reldir ${PROJECT_BINARY_DIR} ${CMAKE_CURRENT_BINARY_DIR})
     execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "import re, hashlib
-unique = hashlib.md5(b'${reldir}${ARGN}').hexdigest()[:5]
+unique = hashlib.sha256(b'${reldir}${ARGN}').hexdigest()[:5]
 print(re.sub('\\W', '_', '${desc} ${reldir} ' + unique))"
     OUTPUT_VARIABLE _target OUTPUT_STRIP_TRAILING_WHITESPACE)
     add_custom_target(${_target} ALL DEPENDS ${ARGN})
diff --git a/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/include/volk_gnsssdr/volk_gnsssdr_common.h b/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/include/volk_gnsssdr/volk_gnsssdr_common.h
index f325d7c1f..387321f10 100644
--- a/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/include/volk_gnsssdr/volk_gnsssdr_common.h
+++ b/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/include/volk_gnsssdr/volk_gnsssdr_common.h
@@ -27,7 +27,10 @@
 //
 // Cross-platform attribute macros not included in VOLK
 //
-#if defined __GNUC__
+#if defined __clang__
+#define __VOLK_GNSSSDR_PREFETCH(addr) __builtin_prefetch(addr)
+#define __VOLK_GNSSSDR_PREFETCH_LOCALITY(addr, rw, locality) __builtin_prefetch(addr, rw, locality)
+#elif defined __GNUC__
 #define __VOLK_GNSSSDR_PREFETCH(addr) __builtin_prefetch(addr)
 #define __VOLK_GNSSSDR_PREFETCH_LOCALITY(addr, rw, locality) __builtin_prefetch(addr, rw, locality)
 #elif _MSC_VER
@@ -44,7 +47,20 @@
 //
 // Cross-platform attribute macros
 //
-#if defined __GNUC__
+#if defined __clang__
+// AppleClang also defines __GNUC__, so do this check first.  These
+// will probably be the same as for __GNUC__, but let's keep them
+// separate just to be safe.
+#define __VOLK_ATTR_ALIGNED(x) __attribute__((aligned(x)))
+#define __VOLK_ATTR_UNUSED __attribute__((unused))
+#define __VOLK_ATTR_INLINE __attribute__((always_inline))
+#define __VOLK_ATTR_DEPRECATED __attribute__((deprecated))
+#define __VOLK_ASM __asm__
+#define __VOLK_VOLATILE __volatile__
+#define __VOLK_ATTR_EXPORT __attribute__((visibility("default")))
+#define __VOLK_ATTR_IMPORT __attribute__((visibility("default")))
+#define __VOLK_PREFETCH(addr) __builtin_prefetch(addr)
+#elif defined __GNUC__
 #define __VOLK_ATTR_ALIGNED(x) __attribute__((aligned(x)))
 #define __VOLK_ATTR_UNUSED __attribute__((unused))
 #define __VOLK_ATTR_INLINE __attribute__((always_inline))
@@ -58,6 +74,7 @@
 #define __VOLK_ATTR_EXPORT
 #define __VOLK_ATTR_IMPORT
 #endif
+#define __VOLK_PREFETCH(addr) __builtin_prefetch(addr)
 #elif _MSC_VER
 #define __VOLK_ATTR_ALIGNED(x) __declspec(align(x))
 #define __VOLK_ATTR_UNUSED
@@ -65,6 +82,7 @@
 #define __VOLK_ATTR_DEPRECATED __declspec(deprecated)
 #define __VOLK_ATTR_EXPORT __declspec(dllexport)
 #define __VOLK_ATTR_IMPORT __declspec(dllimport)
+#define __VOLK_PREFETCH(addr)
 #define __VOLK_ASM __asm
 #define __VOLK_VOLATILE
 #else
@@ -74,6 +92,7 @@
 #define __VOLK_ATTR_DEPRECATED
 #define __VOLK_ATTR_EXPORT
 #define __VOLK_ATTR_IMPORT
+#define __VOLK_PREFETCH(addr)
 #define __VOLK_ASM __asm__
 #define __VOLK_VOLATILE __volatile__
 #endif
diff --git a/src/tests/common-files/tracking_tests_flags.h b/src/tests/common-files/tracking_tests_flags.h
index 0df70dba3..6df70d1c5 100644
--- a/src/tests/common-files/tracking_tests_flags.h
+++ b/src/tests/common-files/tracking_tests_flags.h
@@ -58,6 +58,10 @@ DEFINE_double(DLL_bw_hz_start, 1.0, "DLL Wide configuration start sweep value [H
 DEFINE_double(DLL_bw_hz_stop, 1.0, "DLL Wide configuration stop sweep value [Hz]");
 DEFINE_double(DLL_bw_hz_step, 0.25, "DLL Wide configuration sweep step value [Hz]");
 
+DEFINE_double(fll_bw_hz, 4.0, "FLL filter bandwidth [Hz]");
+DEFINE_bool(enable_fll_pull_in, false, "Enable FLL in pull-in phase");
+DEFINE_bool(enable_fll_steady_state, false, "Enable FLL in steady-state phase");
+
 DEFINE_double(PLL_narrow_bw_hz, 5.0, "PLL Narrow configuration value [Hz]");
 DEFINE_double(DLL_narrow_bw_hz, 0.75, "DLL Narrow configuration value [Hz]");
 
diff --git a/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc b/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc
index b9140b3cd..b886bebee 100644
--- a/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc
+++ b/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc
@@ -661,7 +661,6 @@ void HybridObservablesTest::configure_receiver(
     bool high_dyn)
 {
     config = std::make_shared<InMemoryConfiguration>();
-    config->set_property("Tracking.dump", "true");
     if (high_dyn)
         {
             config->set_property("Tracking.high_dyn", "true");
@@ -670,8 +669,6 @@ void HybridObservablesTest::configure_receiver(
         {
             config->set_property("Tracking.high_dyn", "false");
         }
-    config->set_property("Tracking.smoother_length", std::to_string(smoother_length));
-    config->set_property("Tracking.dump_filename", "./tracking_ch_");
     config->set_property("Tracking.implementation", implementation);
     config->set_property("Tracking.item_type", "gr_complex");
     config->set_property("Tracking.pll_bw_hz", std::to_string(PLL_wide_bw_hz));
@@ -679,6 +676,12 @@ void HybridObservablesTest::configure_receiver(
     config->set_property("Tracking.extend_correlation_symbols", std::to_string(extend_correlation_symbols));
     config->set_property("Tracking.pll_bw_narrow_hz", std::to_string(PLL_narrow_bw_hz));
     config->set_property("Tracking.dll_bw_narrow_hz", std::to_string(DLL_narrow_bw_hz));
+    config->set_property("Tracking.fll_bw_hz", std::to_string(FLAGS_fll_bw_hz));
+    config->set_property("Tracking.enable_fll_pull_in", FLAGS_enable_fll_pull_in ? "true" : "false");
+    config->set_property("Tracking.enable_fll_steady_state", FLAGS_enable_fll_steady_state ? "true" : "false");
+    config->set_property("Tracking.smoother_length", std::to_string(smoother_length));
+    config->set_property("Tracking.dump", "true");
+    config->set_property("Tracking.dump_filename", "./tracking_ch_");
     config->set_property("Observables.implementation", "Hybrid_Observables");
     config->set_property("Observables.dump", "true");
     config->set_property("TelemetryDecoder.dump", "true");
@@ -696,7 +699,7 @@ void HybridObservablesTest::configure_receiver(
             std::memcpy(static_cast<void*>(gnss_synchro_master.Signal), str, 3);  // copy string into synchro char array: 2 char + null
 
             config->set_property("Tracking.early_late_space_chips", "0.5");
-            config->set_property("Tracking.early_late_space_narrow_chips", "0.5");
+            config->set_property("Tracking.early_late_space_narrow_chips", "0.1");
 
             config->set_property("TelemetryDecoder.implementation", "GPS_L1_CA_Telemetry_Decoder");
         }
@@ -743,8 +746,8 @@ void HybridObservablesTest::configure_receiver(
                 }
             config->set_property("Tracking.early_late_space_chips", "0.5");
             config->set_property("Tracking.track_pilot", "true");
-            config->set_property("Tracking.pll_filter_order", "2");
-            config->set_property("Tracking.dll_filter_order", "2");
+            //config->set_property("Tracking.pll_filter_order", "2");
+            //config->set_property("Tracking.dll_filter_order", "2");
 
             config->set_property("TelemetryDecoder.implementation", "Galileo_E5a_Telemetry_Decoder");
         }
@@ -758,8 +761,8 @@ void HybridObservablesTest::configure_receiver(
 
             config->set_property("Tracking.early_late_space_chips", "0.5");
             config->set_property("Tracking.track_pilot", "true");
-            config->set_property("Tracking.pll_filter_order", "2");
-            config->set_property("Tracking.dll_filter_order", "2");
+            //config->set_property("Tracking.pll_filter_order", "2");
+            //config->set_property("Tracking.dll_filter_order", "2");
 
             config->set_property("TelemetryDecoder.implementation", "GPS_L5_Telemetry_Decoder");
         }
@@ -776,6 +779,9 @@ void HybridObservablesTest::configure_receiver(
     std::cout << "implementation: " << config->property("Tracking.implementation", std::string("undefined")) << " \n";
     std::cout << "pll_bw_hz: " << config->property("Tracking.pll_bw_hz", 0.0) << " Hz\n";
     std::cout << "dll_bw_hz: " << config->property("Tracking.dll_bw_hz", 0.0) << " Hz\n";
+    std::cout << "fll_bw_hz: " << config->property("Tracking.fll_bw_hz", 0.0) << " Hz\n";
+    std::cout << "enable_fll_pull_in: " << config->property("Tracking.enable_fll_pull_in", false) << "\n";
+    std::cout << "enable_fll_steady_state: " << config->property("Tracking.enable_fll_steady_state", false) << "\n";
     std::cout << "pll_bw_narrow_hz: " << config->property("Tracking.pll_bw_narrow_hz", 0.0) << " Hz\n";
     std::cout << "dll_bw_narrow_hz: " << config->property("Tracking.dll_bw_narrow_hz", 0.0) << " Hz\n";
     std::cout << "extend_correlation_symbols: " << config->property("Tracking.extend_correlation_symbols", 0) << " Symbols\n";
@@ -785,6 +791,7 @@ void HybridObservablesTest::configure_receiver(
     std::cout << "*****************************************\n";
 }
 
+
 void HybridObservablesTest::check_results_carrier_phase(
     arma::mat& true_ch0,
     arma::vec& true_tow_s,
@@ -792,7 +799,6 @@ void HybridObservablesTest::check_results_carrier_phase(
     const std::string& data_title)
 {
     // 1. True value interpolation to match the measurement times
-
     double t0 = measured_ch0(0, 0);
     int size1 = measured_ch0.col(0).n_rows;
     double t1 = measured_ch0(size1 - 1, 0);
@@ -873,7 +879,6 @@ void HybridObservablesTest::check_results_carrier_phase_double_diff(
     const std::string& data_title)
 {
     // 1. True value interpolation to match the measurement times
-
     double t0 = std::max(measured_ch0(0, 0), measured_ch1(0, 0));
     int size1 = measured_ch0.col(0).n_rows;
     int size2 = measured_ch1.col(0).n_rows;
@@ -969,7 +974,6 @@ void HybridObservablesTest::check_results_carrier_doppler_double_diff(
     const std::string& data_title)
 {
     // 1. True value interpolation to match the measurement times
-
     double t0 = std::max(measured_ch0(0, 0), measured_ch1(0, 0));
     int size1 = measured_ch0.col(0).n_rows;
     int size2 = measured_ch1.col(0).n_rows;
@@ -1062,7 +1066,6 @@ void HybridObservablesTest::check_results_carrier_doppler(
     const std::string& data_title)
 {
     // 1. True value interpolation to match the measurement times
-
     double t0 = measured_ch0(0, 0);
     int size1 = measured_ch0.col(0).n_rows;
     double t1 = measured_ch0(size1 - 1, 0);
@@ -1137,6 +1140,7 @@ void HybridObservablesTest::check_results_carrier_doppler(
         }
 }
 
+
 void HybridObservablesTest::check_results_duplicated_satellite(
     arma::mat& measured_sat1,
     arma::mat& measured_sat2,
@@ -1389,6 +1393,7 @@ void HybridObservablesTest::check_results_duplicated_satellite(
         }
 }
 
+
 bool HybridObservablesTest::save_mat_xy(std::vector<double>& x, std::vector<double>& y, std::string filename)
 {
     try
@@ -1435,7 +1440,6 @@ void HybridObservablesTest::check_results_code_pseudorange(
     const std::string& data_title)
 {
     // 1. True value interpolation to match the measurement times
-
     double t0 = std::max(measured_ch0(0, 0), measured_ch1(0, 0));
     int size1 = measured_ch0.col(0).n_rows;
     int size2 = measured_ch1.col(0).n_rows;
@@ -1522,6 +1526,7 @@ void HybridObservablesTest::check_results_code_pseudorange(
         }
 }
 
+
 bool HybridObservablesTest::ReadRinexObs(std::vector<arma::mat>* obs_vec, Gnss_Synchro gnss)
 {
     // Open and read reference RINEX observables file
@@ -1662,6 +1667,8 @@ bool HybridObservablesTest::ReadRinexObs(std::vector<arma::mat>* obs_vec, Gnss_S
         }
     return true;
 }
+
+
 TEST_F(HybridObservablesTest, ValidationOfResults)
 {
     // Configure the signal generator
@@ -1699,7 +1706,6 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
                 }
         }
 
-
     configure_receiver(FLAGS_PLL_bw_hz_start,
         FLAGS_DLL_bw_hz_start,
         FLAGS_PLL_narrow_bw_hz,
@@ -1708,7 +1714,6 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
         FLAGS_smoother_length,
         FLAGS_high_dyn);
 
-
     for (auto& n : gnss_synchro_vec)
         {
             // setup the signal synchronization, simulating an acquisition
@@ -1814,7 +1819,6 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
             }) << "Failure connecting tracking to the top_block.";
         }
 
-
     ASSERT_NO_THROW({
         std::string file;
         if (!FLAGS_enable_external_signal_file)
@@ -1982,7 +1986,6 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
                 }
         }
 
-
     if (FLAGS_duplicated_satellites_test)
         {
             // special test mode for duplicated satellites
@@ -2083,7 +2086,6 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
                         << "Error finding observation time epoch in the reference data";
                 }
 
-
             for (unsigned int n = 0; n < measured_obs_vec.size(); n++)
                 {
                     // debug save to .mat
@@ -2123,7 +2125,6 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
                         measured_obs_vec.at(n).col(3).colptr(0) + measured_obs_vec.at(n).col(3).n_rows);
                     save_mat_xy(tmp_vector_x6, tmp_vector_y6, std::string("measured_cp_ch_" + std::to_string(n)));
 
-
                     if (epoch_counters_vec.at(n) > 100)  // discard non-valid channels
                         {
                             arma::vec true_TOW_ref_ch_s = true_obs_vec.at(min_pr_ch_id).col(0) - receiver_time_offset_ref_channel_s(0);