First transmission through a real radio path in the project. A 4756-byte
JPEG went from transmitter to receiver over two antennas 60 cm apart at
225 MHz and reassembled byte-identical, reproduced across three runs.
The cable loopback still needs an SMA male-to-male adapter that has not
arrived, so this air run is a track verification, not the controlled
measurement: room levels are not held the way a cable holds them. Its
purpose was to exercise the device wrapper the models cannot cover.
Four defects the software model passed but the hardware exposed, each
reproduced and fixed:
- a 566 528-sample frame did not fit the 262 144 receive buffer, and the
sample stream is not continuous across separate reads, so a frame on the
seam was destroyed. Reception now uses one buffer sized to the frame
- carrier correction was always applied, but with a shared reference the
true offset is near zero and the 80-symbol marker estimate is noise;
correcting by it rotated phase along the whole frame, 65% bit errors
measured. Ported should_apply_cfo_correction from Lab023
- receiver gain of 20 dB left the signal at 0.0003 of full scale. Levels
set by measurement: RX 50 dB, TX -10 dB give zero bit errors with margin
- the error-vector metric returned zero on a failed receive, reporting a
perfect signal where there was none, the same class of defect as the
written-in figures of Lab041. Replaced with an explicit not-computed value
The air TX gain ceiling is now derived from the link budget by antenna
distance rather than a constant. Three loopback modes: software, cable,
air. PROJECT_LOG entry 019 records the run and the defects.
Software and cable results stay reproducible; 125 tests pass, gate passes.
Environment, README, gitignore and the source self-parsing in Lab041.
requirements.txt and requirements-hardware.txt pin the versions actually
verified today on Python 3.13.1, split so the project comes up on a
machine with no SDR: pyadi-iio and libiio are only needed from Lab042 on.
The gitignore contradiction is fixed in the direction that keeps the
project reproducible. data/raw/ was ignored while six files were tracked
anyway, and four of them are the source images Lab007, Lab009, Lab011 and
Lab012 read as input. Untracking them would have broken those labs, so
the rule now carries explicit exceptions instead. Recorded in the README:
lab026_rover_source.mp4 is genuinely absent and Lab026 and Lab027 cannot
run without it.
README replaced. It claimed the next task was to write the first protocol
module, 41 labs later. It now states what exists, that the transmitter
has never been switched on, how to install either environment, how to run
tests, the gate and a lab, and that rover/, ground_station/ and gnuradio/
are still empty. Added rule 9: every number in a report must come from
the current run, transferred values must name their source.
Lab041 no longer parses its own source to check that plot labels are in
Russian. That belonged to presentation, not to model correctness, and
turned the experiment into an analyser of its own text; ast, inspect and
re are no longer imported. Rerun: 180 combinations, 24/24 checks, five
CSV and seven PNG, unchanged.
125 tests pass, gate passes.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Audit found seven numbers in simulate_trial that were neither modelled by
Lab041 nor traceable to their claimed source. Video fraction 0.910 did not
match Lab040 (0.9603); base queue length 31 did not match Lab040 (36-38).
- drop video/telemetry/control delivered fractions and queue length: these
belong to Lab037 and Lab040 and are not modelled here
- drop lab041_traffic_impact.png, which plotted only those metrics
- drop negative_speed_cases and speed_limit_exceeded_cases, never computed,
along with the tautological asserts that checked them
- bind braking parameters to the Lab039 nominal profile via named constants
instead of the literals 0.250 and the divisor 6.0
- cite Lab038 as the source of the transferred video and telemetry loads
- rewrite the invariants section: nine architecture-derived properties now
carry functional-check references, five unmeasurable ones move to their
own section
- extend check 04 with negative speed and the 15 m/s boundary
- state explicitly what the matrix rolls, what the architecture fixes and
what is not modelled at all
Regenerated: 180 combinations, 24/24 checks, five CSV and seven PNG.
Six columns removed, no retained value changed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
