GNSS-SDR v0.0.9 released

This release has several improvements, addition of new features and bug fixes in many dimensions.

Improvements in Accuracy:

• Major rewriting in the generation of pseudoranges.
• Fixed bug in Galileo E5a/I codes.
• Fixed bug in Galileo E1 correlator spacing.
• Fixed bug that was causing errors in receivers above the troposphere.
• Fixed 16-bit complex resampler.
• Improved time tracking algorithm.
• Added Bancroft’s algorithm implementation for PVT initialization.

Improvements in Availability:

• Improved numerical stability of the PVT solution. The infamous bug that was causing apparently random error peaks has finally been fixed.

Improvements in Efficiency:

• VOLK_GNSSSDR: Added NEON, AVX and unaligned protokernels for volk_gnsssdr_32f_index_max_32 kernel.
• VOLK_GNSSSDR: Added volk_gnsssdr-config-info to the list of generated executables.

Improvements in Flexibility:

• Added maximum number of dwells in the Tong algorithm.

Improvements in Interoperability:

• Added six new Galileo satellites: FM7, FM10, FM11, FM12, FM13, FM14.
• The Hybrid_Observables and Hybrid_PVT implementations can now handle more types of GNSS signals.
• The RINEX printer can now print L2C and E5a observables and navigation files, including multiband configurations.
• Added RTCM 3.2 output to more receiver configurations.

Improvements in Maintainability:

• The VOLK_GNSSSDR library can now be built with Python 3. Switched dependencies for VOLK_GNSSDR: from (old, python2.7-only) python-cheetah templates to Python3 friendly python-mako and python-six. So, Python-cheetah dependency has been dropped, and python-mako and python-six have been added.
• If suitable versions of gflags, glog, armadillo or googletest are not found in the system, they will be downloaded and built at compile time (versions 2.2.0, 0.3.4, 7.600.2 and 1.8.0, respectively).
• Fixed more than 30 defects detected by Coverity Scan.
• Added CMake Python finder and module checker.
• Deleted files related to CPack.
• Fixes, updates and improvements in the documentation.
• Improvements in CMake scripts: General code cleaning and addition of comments. Improved user information in case of failure. Improved detection of dependencies in more processor architectures (e.g., aarch64).

Improvements in Marketability:

• Reduced time from a commit to deployment (see virtualization mechanisms in Portability).

Improvements in Portability:

• Now GNSS-SDR can be run in virtual environments through snap packages (see https://github.com/carlesfernandez/snapcraft-sandbox) and docker images (see https://github.com/carlesfernandez/docker-gnsssdr).
• Now GNSS-SDR is adapted to cross-compiling environments for embedded devices (see https://github.com/carlesfernandez/oe-gnss-sdr-manifest).
• BLAS and LAPACK libraries are not longer mandatory on ARM devices.

Improvements in Scalability:

• Fixed bug in acquisition with data rates higher than 16 Msps in 4ms code periods.

Improvements in Testability:

• Major QA source code refactoring: they have been split into src/tests/unit-tests and src/tests/system-tests folders. They are optionally built with the ENABLE_UNIT_TESTING=ON (unit testing QA code), ENABLE_UNIT_TESTING_EXTRA=ON (unit tests that require extra files downloaded at configure time), ENABLE_SYSTEM_TESTING=ON (system tests, such as measurement of Time-To-First-Fix) and ENABLE_SYSTEM_TESTING_EXTRA=ON (extra system test requiring external tools, automatically downloaded and built at building time) configuration flags. The EXTRA options also download and build a custom software-defined signal generator and version 2.9 of GPSTk, if not already found on the system. Download and local link of version 2.9 can be forced by ENABLE_OWN_GPSTK=ON building configuration flag. Only ENABLE_UNIT_TESTING is set to ON by default.
• Unit tests added: CPU_multicorrelator_test and GPU_multicorrelator_test measure computer performance in multicorrelator setups.
• Extra unit tests added: GpsL1CADllPllTracking and GpsL1CATelemetryDecoderTest.
• System test added: ttff_gps_l1 performs a set of cold / assisted runs of the software receiver and computes statistics about the obtained Time To First Fix.
• Extra system test added: obs_gps_l1_system_test uses an external software-defined signal generator to produce raw digital GNSS signal from a RINEX navigation file and a position (static or dynamic), processes it with GNSS-SDR, and then compares the RINEX observation file produced by the software receiver to that produced by the signal generator.
• Software Development Kit provided for embedded devices (see https://gnss-sdr.org/docs/tutorials/cross-compiling/).

Improvements in Usability:

• Now the block factory automatically detects Channel input data type, so it is no longer required to specify Channel.input_type in the configuration. An error raises if Acquisition and Tracking Blocks are not configured with the same input data type.
• Block names changed from L2_M to L2C.
• Documentation available at https://gnss-sdr.org/docs/
• Improved tools for compilation, execution and testing in embedded devices.

As usual, compressed tarballs are available from GitHub and Sourceforge.

In order to make GNSS-SDR more easily referenced, and to promote reproducible research, each software release gets a Digital Object Identifier provided by Zenodo. The DOI for GNSS-SDR v0.0.9 is 10.5281/zenodo.291371.