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 rata rates higher than 16 Msps in 4ms code periods.
Improvements in Testability:
Major QA source code refactoring: they has 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.
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.
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 http://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 http://gnss-sdr.org/docs/
Improved tools for compilation, execution and testing in embedded devices.
See the definitions of concepts and metrics at http://gnss-sdr.org/design-forces/