Fix building of obsdiff tool, add README file

src/utils/CMakeLists.txt

@@ -8,8 +8,8 @@
 #
 
 add_subdirectory(front-end-cal)
-add_subdirectory(rinex_tools)
 
 if(ENABLE_UNIT_TESTING_EXTRA OR ENABLE_SYSTEM_TESTING_EXTRA OR ENABLE_FPGA)
+    add_subdirectory(rinex-tools)
     add_subdirectory(rinex2assist)
 endif()

src/utils/rinex-tools/CMakeLists.txt

@@ -0,0 +1,52 @@
+# Copyright (C) 2012-2020  (see AUTHORS file for a list of contributors)
+#
+# GNSS-SDR is a software-defined Global Navigation Satellite Systems receiver
+#
+# This file is part of GNSS-SDR.
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+
+find_package(GPSTK QUIET)
+if(NOT GPSTK_FOUND OR ENABLE_OWN_GPSTK)
+    include(GNUInstallDirs)
+    set(GPSTK_LIBRARY ${CMAKE_CURRENT_SOURCE_DIR}/../../../thirdparty/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/install/${CMAKE_INSTALL_LIBDIR}/${CMAKE_FIND_LIBRARY_PREFIXES}gpstk${CMAKE_SHARED_LIBRARY_SUFFIX})
+    set(GPSTK_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../../thirdparty/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/install/include)
+endif()
+
+set(obsdiff_HEADERS obsdiff_flags.h)
+source_group(Headers FILES ${obsdiff_HEADERS})
+
+add_executable(obsdiff ${CMAKE_CURRENT_SOURCE_DIR}/obsdiff.cc ${obsdiff_HEADERS})
+set_property(TARGET obsdiff PROPERTY CXX_STANDARD 14)  # Required by GPSTk
+target_include_directories(obsdiff PUBLIC ${CMAKE_SOURCE_DIR}/src/tests/common-files)
+
+if(NOT GPSTK_FOUND OR ENABLE_OWN_GPSTK)
+    add_dependencies(obsdiff gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION})
+endif()
+
+target_link_libraries(obsdiff
+    PUBLIC
+        Armadillo::armadillo
+        Threads::Threads
+        Gflags::gflags
+        Matio::matio
+        core_system_parameters
+        ${GPSTK_LIBRARY}
+)
+
+target_include_directories(obsdiff
+    PUBLIC
+        ${GPSTK_INCLUDE_DIR}/gpstk
+        ${GPSTK_INCLUDE_DIR}
+)
+
+add_custom_command(TARGET obsdiff POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:obsdiff>
+    ${CMAKE_SOURCE_DIR}/install/$<TARGET_FILE_NAME:obsdiff>
+)
+
+install(TARGETS obsdiff
+    RUNTIME DESTINATION bin
+    COMPONENT "obsdiff"
+)

src/utils/rinex-tools/README.md

@@ -0,0 +1,45 @@
+obsdiff
+-------
+
+[comment]: # (
+SPDX-License-Identifier: GPL-3.0-or-later
+)
+
+[comment]: # (
+SPDX-FileCopyrightText: Javier Arribas, 2020. <jarribas@cttc.es>
+)
+
+This program computes Single-difference and Double-difference from RINEX observation files.
+
+## Building
+
+This program is built along with GNSS-SDR if the options `ENABLE_UNIT_TESTING_EXTRA` or `ENABLE_SYSTEM_TESTING_EXTRA` are set to `ON` when calling CMake:
+
+```
+$ cmake -DENABLE_SYSTEM_TESTING_EXTRA=ON ..
+$ make obsdiff
+$ sudo make install
+```
+
+The last step is optional. Without it, you still will get the executable at `../install/obsdiff`.
+
+
+## Usage
+
+```
+$ obsdiff --ref_rinex_obs=reference.20o --test_rinex_obs=rover.20o
+```
+
+Available command-line flags:
+
+| **flag**                 | **Default value** | **Description**  |
+|:------------------------:|:-----------------:|:-----------------|
+| `skip_obs_transitory_s`  | `30.0`            | Skip the initial observable outputs to avoid transitory results [s]. |
+| `skip_obs_ends_s`        | `5.0`             | Skip the lasts observable outputs to avoid transitory results [s]. |
+| `single_diffs`           | `false`           | [`true`, `false`]: If `true`, the program also computes the single difference errors for [Carrier Phase](https://gnss-sdr.org/docs/sp-blocks/observables/#carrier-phase-measurement) and [Doppler](https://gnss-sdr.org/docs/sp-blocks/observables/#doppler-shift-measurement) measurements (requires LO synchronization between receivers). |
+| `compare_with_5X`        | `false`           | [`true`, `false`]: If `true`, compares the E5a Doppler and Carrier Phases with the E5 full Bw in RINEX (expect discrepancy due to the center frequencies difference). |
+| `dupli_sat`              | `false`           | [`true`, `false`]: If `true`, enables special observable test mode where the scenario contains duplicated satellite orbits. |
+| `dupli_sat_prns`         | `1,2,3,4`         | List of duplicated satellites PRN pairs (_i.e._, `1,2,3,4` indicates that the PRNs 1,2 share the same orbit. The same applies for PRNs 3,4). |
+| `ref_rinex_obs`          | `reference.obs`   | Filename of reference RINEX observation file. |
+| `test_rinex_obs`         | `test.obs`        | Filename of tested RINEX observation file. |
+| `show_plots`             | `true`            | [`true`, `false`]: If `true`, and if [gnuplot](http://www.gnuplot.info/) is found on the system, displays results plots on screen. Please set it to `false` for non-interactive testing. |

src/utils/rinex-tools/obsdiff_flags.h

@@ -0,0 +1,36 @@
+/*!
+ * \file obsdiff_flags.h
+ * \brief Helper file for unit testing
+ * \author Javier Arribas, 2020. jarribas(at)cttc.es
+ *
+ *
+ * -------------------------------------------------------------------------
+ *
+ * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ *
+ * GNSS-SDR is a software defined Global Navigation
+ *          Satellite Systems receiver
+ *
+ * This file is part of GNSS-SDR.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_OBSDIFF_FLAGS_H
+#define GNSS_SDR_OBSDIFF_FLAGS_H
+
+#include <gflags/gflags.h>
+#include <limits>
+
+DEFINE_double(skip_obs_transitory_s, 30.0, "Skip the initial observable outputs to avoid transitory results [s]");
+DEFINE_double(skip_obs_ends_s, 5.0, "Skip the lasts observable outputs to avoid transitory results [s]");
+DEFINE_bool(single_diffs, false, "Compute also the single difference errors for Accumulated Carrier Phase and Carrier Doppler (requires LO synchronization between receivers)");
+DEFINE_bool(compare_with_5X, false, "Compare the E5a Doppler and Carrier Phases with the E5 full bw in RINEX (expect discrepancy due to the center frequencies difference)");
+DEFINE_bool(dupli_sat, false, "Enable special observable test mode where the scenario contains duplicated satellite orbits");
+DEFINE_string(dupli_sat_prns, "1,2,3,4", "List of duplicated satellites PRN pairs (i.e. 1,2,3,4 indicates that the PRNs 1,2 share the same orbit. The same applies for PRNs 3,4)");
+DEFINE_string(ref_rinex_obs, "reference.obs", "Filename of reference RINEX observation file");
+DEFINE_string(test_rinex_obs, "test.obs", "Filename of test RINEX observation file");
+
+#endif