diff --git a/CMakeLists.txt b/CMakeLists.txt
index 416e44fb..57b069d0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,8 +1,8 @@
 cmake_minimum_required(VERSION 3.5)
 project(ndt_omp)
 
-add_definitions(-std=c++14)
-set(CMAKE_CXX_FLAGS "-std=c++14")
+add_definitions(-std=c++17)
+set(CMAKE_CXX_FLAGS "-std=c++17")
 
 # Compile flags for SIMD instructions
 if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "x86_64")
@@ -20,78 +20,6 @@ endif()
 # pcl 1.7 causes a segfault when it is built with debug mode
 set(CMAKE_BUILD_TYPE "RELEASE")
 
-if($ENV{ROS_VERSION} EQUAL 1)
-# ROS1
-find_package(catkin REQUIRED COMPONENTS
-  roscpp
-  pcl_ros
-)
-
-find_package(PCL 1.7 REQUIRED)
-include_directories(${PCL_INCLUDE_DIRS})
-link_directories(${PCL_LIBRARY_DIRS})
-add_definitions(${PCL_DEFINITIONS})
-
-message(STATUS "PCL_INCLUDE_DIRS:" ${PCL_INCLUDE_DIRS})
-message(STATUS "PCL_LIBRARY_DIRS:" ${PCL_LIBRARY_DIRS})
-message(STATUS "PCL_DEFINITIONS:" ${PCL_DEFINITIONS})
-
-find_package(OpenMP)
-if (OPENMP_FOUND)
-    set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
-    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
-endif()
-
-###################################
-## catkin specific configuration ##
-###################################
-catkin_package(
-  INCLUDE_DIRS include
-  LIBRARIES ndt_omp
-)
-
-###########
-## Build ##
-###########
-include_directories(include)
-include_directories(
-  ${catkin_INCLUDE_DIRS}
-)
-
-add_library(ndt_omp
-  src/pclomp/voxel_grid_covariance_omp.cpp
-  src/pclomp/ndt_omp.cpp
-  src/pclomp/gicp_omp.cpp
-)
-
-add_executable(align
-  apps/align.cpp
-)
-add_dependencies(align
-  ndt_omp
-)
-target_link_libraries(align
-  ${catkin_LIBRARIES}
-  ${PCL_LIBRARIES}
-  ndt_omp
-)
-
-#############
-## INSTALL ##
-#############
-
-install(
-  TARGETS
-    ndt_omp
-  ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
-  RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
-  LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
-)
-
-# install headers
-install(DIRECTORY include/pclomp
-        DESTINATION ${CATKIN_GLOBAL_INCLUDE_DESTINATION})
-else()
 # ROS2
 find_package(ament_cmake_auto REQUIRED)
 ament_auto_find_build_dependencies()
@@ -155,5 +83,3 @@ target_link_libraries(regression_test
   ${PCL_LIBRARIES}
   ndt_omp multigrid_ndt_omp
 )
-
-endif()
diff --git a/docker/melodic/Dockerfile b/docker/melodic/Dockerfile
deleted file mode 100644
index 0d303842..00000000
--- a/docker/melodic/Dockerfile
+++ /dev/null
@@ -1,26 +0,0 @@
-FROM ros:melodic
-
-RUN apt-get update && apt-get install -y --no-install-recommends \
-  wget nano build-essential libomp-dev clang lld\
-  ros-melodic-geodesy ros-melodic-pcl-ros ros-melodic-nmea-msgs \
-  ros-melodic-rviz ros-melodic-tf-conversions ros-melodic-libg2o \
-  && apt-get clean \
-  && rm -rf /var/lib/apt/lists/*
-
-RUN mkdir -p /root/catkin_ws/src
-WORKDIR /root/catkin_ws/src
-RUN /bin/bash -c '. /opt/ros/melodic/setup.bash; catkin_init_workspace'
-RUN git config --global http.postBuffer 2M
-RUN git clone https://github.com/SMRT-AIST/fast_gicp.git --recursive --depth=1
-RUN git clone https://github.com/koide3/hdl_graph_slam.git --depth=1
-
-COPY . /root/catkin_ws/src/ndt_omp/
-
-WORKDIR /root/catkin_ws
-RUN /bin/bash -c '. /opt/ros/melodic/setup.bash; catkin_make'
-RUN sed -i "6i source \"/root/catkin_ws/devel/setup.bash\"" /ros_entrypoint.sh
-
-WORKDIR /
-
-ENTRYPOINT ["/ros_entrypoint.sh"]
-CMD ["bash"]
diff --git a/docker/melodic_llvm/Dockerfile b/docker/melodic_llvm/Dockerfile
deleted file mode 100644
index d49f8f4b..00000000
--- a/docker/melodic_llvm/Dockerfile
+++ /dev/null
@@ -1,28 +0,0 @@
-FROM ros:melodic
-
-RUN apt-get update && apt-get install -y --no-install-recommends \
-  wget nano build-essential libomp-dev clang lld\
-  ros-melodic-geodesy ros-melodic-pcl-ros ros-melodic-nmea-msgs \
-  ros-melodic-rviz ros-melodic-tf-conversions ros-melodic-libg2o \
-  && apt-get clean \
-  && rm -rf /var/lib/apt/lists/*
-
-RUN mkdir -p /root/catkin_ws/src
-WORKDIR /root/catkin_ws/src
-RUN /bin/bash -c '. /opt/ros/melodic/setup.bash; catkin_init_workspace'
-RUN git config --global http.postBuffer 2M
-RUN git clone https://github.com/SMRT-AIST/fast_gicp.git --recursive --depth=1
-RUN git clone https://github.com/koide3/hdl_graph_slam.git --depth=1
-
-COPY . /root/catkin_ws/src/ndt_omp/
-
-RUN update-alternatives --install /usr/bin/ld ld /usr/bin/ld.lld 50
-
-WORKDIR /root/catkin_ws
-RUN /bin/bash -c '. /opt/ros/melodic/setup.bash; CC=clang CXX=clang++ catkin_make'
-RUN sed -i "6i source \"/root/catkin_ws/devel/setup.bash\"" /ros_entrypoint.sh
-
-WORKDIR /
-
-ENTRYPOINT ["/ros_entrypoint.sh"]
-CMD ["bash"]
diff --git a/docker/noetic/Dockerfile b/docker/noetic/Dockerfile
deleted file mode 100644
index 0bfb865b..00000000
--- a/docker/noetic/Dockerfile
+++ /dev/null
@@ -1,26 +0,0 @@
-FROM ros:noetic
-
-RUN apt-get update && apt-get install -y --no-install-recommends \
-  wget nano build-essential libomp-dev clang lld git\
-  ros-noetic-geodesy ros-noetic-pcl-ros ros-noetic-nmea-msgs \
-  ros-noetic-rviz ros-noetic-tf-conversions ros-noetic-libg2o \
-  && apt-get clean \
-  && rm -rf /var/lib/apt/lists/*
-
-RUN mkdir -p /root/catkin_ws/src
-WORKDIR /root/catkin_ws/src
-RUN /bin/bash -c '. /opt/ros/noetic/setup.bash; catkin_init_workspace'
-RUN git config --global http.postBuffer 2M
-RUN git clone https://github.com/SMRT-AIST/fast_gicp.git --recursive --depth=1
-RUN git clone https://github.com/koide3/hdl_graph_slam.git --depth=1
-
-COPY . /root/catkin_ws/src/ndt_omp/
-
-WORKDIR /root/catkin_ws
-RUN /bin/bash -c '. /opt/ros/noetic/setup.bash; catkin_make'
-RUN sed -i "6i source \"/root/catkin_ws/devel/setup.bash\"" /ros_entrypoint.sh
-
-WORKDIR /
-
-ENTRYPOINT ["/ros_entrypoint.sh"]
-CMD ["bash"]
diff --git a/docker/noetic_llvm/Dockerfile b/docker/noetic_llvm/Dockerfile
deleted file mode 100644
index d8689374..00000000
--- a/docker/noetic_llvm/Dockerfile
+++ /dev/null
@@ -1,28 +0,0 @@
-FROM ros:noetic
-
-RUN apt-get update && apt-get install -y --no-install-recommends \
-  wget nano build-essential libomp-dev clang lld git\
-  ros-noetic-geodesy ros-noetic-pcl-ros ros-noetic-nmea-msgs \
-  ros-noetic-rviz ros-noetic-tf-conversions ros-noetic-libg2o \
-  && apt-get clean \
-  && rm -rf /var/lib/apt/lists/*
-
-RUN mkdir -p /root/catkin_ws/src
-WORKDIR /root/catkin_ws/src
-RUN /bin/bash -c '. /opt/ros/noetic/setup.bash; catkin_init_workspace'
-RUN git config --global http.postBuffer 2M
-RUN git clone https://github.com/SMRT-AIST/fast_gicp.git --recursive --depth=1
-RUN git clone https://github.com/koide3/hdl_graph_slam.git --depth=1
-
-COPY . /root/catkin_ws/src/ndt_omp/
-
-RUN update-alternatives --install /usr/bin/ld ld /usr/bin/ld.lld 50
-
-WORKDIR /root/catkin_ws
-RUN /bin/bash -c '. /opt/ros/noetic/setup.bash; CC=clang CXX=clang++ catkin_make'
-RUN sed -i "6i source \"/root/catkin_ws/devel/setup.bash\"" /ros_entrypoint.sh
-
-WORKDIR /
-
-ENTRYPOINT ["/ros_entrypoint.sh"]
-CMD ["bash"]