and reloading it from the XML assistance files, which could replace a
fresher, live-decoded almanac with a stale snapshot from disk, and the
handler now uses the visible-satellite list it computed instead of
prioritizing an empty one.
Visibility-aware acquisition search (GNSS-SDR.enable_visibility_aware_search):
- Classify GLONASS and QZSS satellites too. GLONASS positions come from the
GNAV almanac (new Glonass_Gnav_Almanac::satellite_position with the
standard perturbation model), so the search order benefits before any
GLONASS ephemeris is decoded.
- PVT publishes a lock-free navigation snapshot (ephemeris, almanac, UTC
models per system) that the classifier reads instead of locking the PVT
maps on every recompute.
- Recompute on new navigation data, on position changes larger than
visibility_recompute_position_threshold_m, every
visibility_recompute_interval_s, and when the almanac ages out; fix the
periodic and position-triggered recomputes that never fired, and the
off-by-one that excluded satellites in [mask, mask+1) degrees.
- Enter the start-up standby only when the feature is enabled, so the
default search order is untouched.
Secondary-frequency acquisition assistance:
- Do not start an acquisition on the PRN 0 placeholder left on assisted
channels at connect time; it threw inside the control thread and left the
flowgraph running headless with the secondary band never acquired.
- Match GLONASS assistance by FDMA frequency channel: the search pool keeps
one slot per channel while tracked L1 channels report the decoded slot, so
L2 was never picked.
- Assist from locked channels before their telemetry is decoded: the
observables status now reports tracking-only channels and the flowgraph
keeps a separate tracking map for the assisted search.
WARMSTART used to clear ephemeris and almanac and then reload both
from local XML assistance files, which can silently regress the
receiver's live-accumulated almanac (new satellites/pages demodulated
since last start) back to whatever stale snapshot happens to be on
disk. It also never wrote anything back to disk first, so this was a
one-way loss with no merge.
Add PvtInterface::clear_ephemeris_keep_almanac(), which clears only
the ephemeris maps and leaves almanac untouched, and use it in
WARMSTART instead of clear_ephemeris() + read_assistance_from_XML().
This matches the classic cold/warm/hot start table (warm: almanac
current, ephemeris unknown/stale) using whatever almanac the receiver
already has, rather than a file that can't be any more current than
that.
Also fixes get_visible_sats()'s return value never being assigned to
visible_satellites in the WARMSTART handler, so priorize_satellites()
was always reordering the queue with an empty list.
- The executable file and the default configuration file is now changed from "./install/mercurio" and "./conf/mercurio.conf" to "./install/gnss-sdr" and "./conf/gnss-sdr.conf", respectively.
- Configuration file structure changed to define in a single entry the internal sampling frequency (after the signal conditioner). NOTICE that this change affects the all the adapters (acquisition, tracking, telemetry_decoder, observables, and PVT). All the adapters are now modified to work with this feature.
- Moved several in-line GPS L1 CA parameters (a.k.a magic numbers..) to ./src/core/system_parameters/GPS_L1_CA.h definition file.
- Tracking blocks now uses DOUBLE values in their outputs.
- Observables and PVT now are separated. PVT and their associated libraries are moved to ./src/algorithms/PVT
- Temporarily disabled the RINEX output (I am working on that!)
- GNSS-SDR screen output now gives extended debug information of the receiver status and events. In the future, this output will be redirected to a log file.
- Bug fixes:
- FILE_SIGNAL_SOURCE now works correctly when the user configures GNSS-SDR to process the entire file.
- GPS_L1_CA_DLL_PLL now computes correctly the PRN start values.
- GPS_L1_CA_DLL_FLL_PLL now computes correctly the PRN start values.
- Several modifications in GPS_L1_CA_Telemetry_Decoder, GPS_L1_CA_Observables, and GPS_L1_CA_PVT modules to fix the GPS position computation.
- New features
- Tracking blocks perform a signal integrity check against NaN outliers before the correlation process.
- Tracking and PVT binary dump options are now documented and we provide MATLAB libraries and sample files to read it. Available in ./utils/matlab" and "./utils/matlab/libs"
- Observables output rate can be configured. This option enables the GPS L1 CA PVT computation at a maximum rate of 1ms.
- GPS_L1_CA_PVT now can perform a moving average Latitude, Longitude, and Altitude output for each of the Observables output. It is configurable using the configuration file.
- Added Google Earth compatible Keyhole Markup Language (KML) output writer class (./src/algorithms/PVT/libs/kml_printer.h and ./src/algorithms/PVT/libs/kml_printer.cc ). You can see the receiver position directly using Google Earth.
- We provide a master configuration file which includes an in-line documentation with all the new (and old) options. It can be found in ./conf/master.conf
git-svn-id: https://svn.code.sf.net/p/gnss-sdr/code/trunk@84 64b25241-fba3-4117-9849-534c7e92360d
Carles Fernandez