Four things asked for in turn, landing together because they run through the
same files.
THE MAPS. The tiles were already cached and always had been -- a second
evening on the same view was measured at nought network requests -- but the
work done on them was not. Every window open decoded forty PNGs and resampled
a megapixel and a half into this program's own projection, for an answer that
cannot have changed, because a coastline does not move. The finished map is
kept beside the tiles now: 0.61 seconds become 0.01, byte for byte identical,
two hundred kilobytes a view. Both windows and both kinds of still picture get
it, all four reaching the ground through one function. A map with squares
missing is deliberately not kept, since caching a hole would keep it for a
month and the point of calling a partial map provisional is that it is asked
for again. And because this adds a disk consumer, the whole cache is now
pruned to four hundred megabytes, least recently *used* first: a tile fetched a
year ago and looked at last night is the receiver's own neighbourhood, and
discarding that to keep last week's holiday is the wrong way round.
THE LOOKUPS. APRS and FT8 now ask who each station is licensed to. Every
other mode that hears a callsign already did -- speech transcripts, Morse
idents, the recording browser -- and all five resolve through one file, so a
callsign heard on two bands is asked about once. The rules for finding the
licensed callsign inside a heard one are now in one place rather than per band,
because getting them wrong is silent: a register asked about W1AW-9 returns
nothing, which looks exactly like a station that is not licensed. An SSID, a
rover suffix, a guest prefix, a digipeater alias and an unspelled hash all come
off or are refused.
The bug worth recording is that the first cut of this did the lookups and threw
them away. The book has to be told to save and was not, so every evening would
have asked the register about the same net again -- which is the one thing
caching them was for, and is invisible from inside a single run because the
answers are all in memory while it lasts. Caught by looking at the file on
disk rather than at the display. There is a test for each side of it now, and a
register of which modules resolve callsigns at all, which fails when a new one
starts so that somebody has to decide whether it should.
THE REGISTER. c in saunterbrowse opens everything ever looked up: sixty-odd
callsigns and sixteen hundred aircraft here, every field of each in two columns
because a licence has a dozen and a screen is wider than it is tall. tab
switches, / searches every field rather than the name -- the question is
usually "who was in Arizona" rather than "which callsign" -- and g opens the
place in a browser. Only the coordinates go into that link: a map does not
need to be told whose licence it is looking at, and the link is the one part of
this that leaves the machine. A headless box, which is the normal case for a
receiver, gets the coordinates printed instead. Callsigns no register could
place are kept rather than dropped, because "asked about, and in no register
reachable from here" is a fact about a station.
THE FRONT OF IT. A title screen for each program: five rows of blocks cut by
hand, a figlet dependency to draw eleven letters being the largest thing that
would then be in the requirements, coloured blue to red across the width, which
is the ramp every waterfall here already uses because it is what a spectrum
looks like. The interesting part is where it does not appear -- everything
here can be piped into something else and a banner in the middle of that is
corruption rather than decoration, so anything that is not a terminal gets
nothing, --help is untouched because it is drawn after parsing, --no-splash
turns it off for a run and BANDSAUNTER_NO_SPLASH=1 for good.
And the address. INSTALL.md said "git clone <the repository>" for a long time:
a placeholder in the first command anybody types, unnoticed because nothing
reads install instructions except somebody installing, who then cannot. It is
filled in, along with the readme, the metadata, both manuals and the Homepage
field of all three packages. The tile server's User-Agent pointed at a topic
listing on somebody else's site for want of an address of its own; the usage
policy of that service asks for one naming the application and giving somewhere
to look it up, so an operator with a question about the traffic has somebody to
ask, and now it gives the real one. Seven tests so the placeholder cannot come
back, verified by putting it back and watching two of them fail.
One thing forced by all this: the keys page in saunterbrowse was exactly as
tall as an eighty-by-twenty-four terminal, so the register entry pushed "q
quit" off the bottom. A test caught it. Home and End have merged into the
Page Up line, which were always the same thought.
THE WINDOWS. They open maximised now, this being a map and the thing anybody
wants more of being map; f goes to true full screen and back, and is written
along the top of the screen because a window with no frame is one somebody has
to know a key to get out of. Maximised rather than frameless by default,
because the title bar is where the band and the frequency are written.
And a map made bigger now gets a sharper map, which it did not. The window
only ever re-examined the ground when the view left the box that had been
fetched, so a window opened at its default size and taken to the whole screen
kept the map it started with until an aircraft wandered far enough to move it
-- on a quiet band, a long time to look at a blurred coastline. Measured
before it was believed: 1100 to 1920 asked for nothing and stretched a
1364-pixel map across 1920, then across 3840. It now compares map pixels per
degree in hand against what the view wants, and asks when it is being blown up
by more than fifteen per cent.
That comparison has to be per degree rather than pixel against pixel, which a
surviving mutation was what established: the fetched box is a quarter wider
than the view, so a map with exactly as many pixels as the window is wide has
only four fifths of them on the screen. The two ways of measuring agree
everywhere except a narrow band, and the realistic case sits inside it. There
is a test pinning that case now. Asking is safe at any size, because the
request is keyed on the window's dimensions: once answered, nothing more is
asked, which is what stops a window larger than the tile budget can cover from
asking all evening.
The braille, while this was open. The banners were blocks in capitals; they
are braille in mixed case, two dots wide and four tall to a character, which is
eight times the detail and is what makes room for two heights of letter at
once -- a five-row block font has no second height to spend, so the name came
out shouted. Two attempts failed first: thin one-dot strokes came out as
confetti, because braille dots render as dots and a one-dot stroke reads as a
dotted line rather than a line. What worked was cutting the font small, at cap
height seven where there is only one way to draw each letter, and doubling it.
Coloured deep blue through cyan to a cool white, which is deliberately not the
waterfall ramp the rest of the program draws in: that one has to run to red
because it stands in for a spectrum, and a title screen stands in for nothing.
One hundred and four new tests. Full suite 2892 passed. Built as
2026-09-24_01.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016PsWPTweCT6pwxKngvVxcg
The terminal board says what is overhead. This says where: a real map
with the aircraft moving on it as the frames arrive, and beside each one a
box carrying everything known about the flight -- type and registration,
who operates it, where it came from and where it is going, height with a
rate of climb, speed and heading, how far away and on what bearing, its
position, how many frames it has sent and how long since the last one.
Qt is asked for and not required. Four bindings are tried, the module
imports on a machine with none of them, and asking for the window without
one gets the instructions rather than a traceback -- before the receiver
is opened, since nothing is gained by taking the dongle for a window that
cannot be drawn.
In the menu, "listen now" is now "passive capture" with a realtime
display beside it. Closing the window leaves exactly the files pressing
control-C leaves, because listen and watch share one read loop and one
finishing step; the receiver runs on its own thread, so a slow repaint
cannot cost a frame and a slow tile fetch cannot stall the picture.
The animation's labels grew to match: flight level and speed, type and
registration, and both ends of the route, each with a small flag of the
country its airport is in. The flags are a table rather than a network --
twelve pixels by eight, where a flag is the arrangement that makes one
recognisable rather than a rendering of the real thing -- and a country
not in the table is named by its two letters, since a flag that is nearly
another country's is worse than none. Where a route arrives as bare
codes the country comes from the ICAO prefix.
Four things found on the way. The window ignored --seconds, so "listen
for ten minutes" meant something different with a window open; it closes
itself now. The register was being asked twice per aircraft, once for
labels and once for airport positions. Cached routes had no country in
them, so the first real redraw drew no flags at all -- routes are
versioned now. And past fourteen aircraft on one frame the labels go
back to the callsign, the height and the speed, because five lines beside
each of three hundred aircraft is a page of overlapping text with a map
somewhere behind it.
Long names are folded rather than allowed to stretch a box, breaking at
the arrow of a route so the two ends stay whole; and the animation's
label placement gained the same ring search the window uses, having only
ever tried four spots.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016PsWPTweCT6pwxKngvVxcg
The program had no licence file at all, and pyproject claimed MIT into
the void. It is now the GNU General Public License, version 3 or later:
LICENSE holds the text verbatim, pyproject declares it with the OSI
classifier, both .deb builds write /usr/share/doc/<pkg>/copyright in the
machine-readable format Policy requires, both manuals carry a COPYING
section, and --version prints the GNU notice on both programs.
INSTALL.md is the step-by-step: what you need, the Debian package, the
virtual environment for everywhere else, how to check it worked, every
optional dependency with what it buys and what happens without it, and
the errors people actually hit first -- PEP 668 at the top, because on
Debian a plain "pip install ." refuses and reads as a broken program.
Speech transcription gets its own four steps, because it is the only
part with a real download in it: the recogniser into the environment
bandsaunter runs from, checking it took, the model (base.en, 148 MB,
from Hugging Face into ~/.cache/huggingface, fetched deliberately rather
than in the middle of a scan), then turning it on. With the sizes of
every model, the offline routes, and what to do when --engines says no
although pip says yes.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016PsWPTweCT6pwxKngvVxcg
Resizing the terminal during a scan left the screen full of wreckage:
box corners in the middle of a line, borders twice the width of the
window, a "receiver" header printed eight times down the left edge. Four
separate defects, which is why it looked so bad.
Live rendering works by moving the cursor back over the frame it drew
last time and overwriting it. That is only correct while the frame is
still where it was put, and none of these programs noticed when it was
not.
1. Nothing detected a resize. Both the scan display and saunterbrowse
now compare the console size on every frame and clear the screen when
it changes -- polled rather than handled as a signal, because the
display is redrawn several times a second anyway and a signal handler
that runs in the middle of a write has to be right about far more than
this does. Anything printed before the scan started scrolls away at
that point, which the manual now says.
2. The layout's model of its own height was wrong, in two places that
cancelled. The sweep panel was counted as one line shorter than it
is, the hit list as one line taller. The sum came out right whenever
both were drawn and wrong on a terminal too short for the hit list --
where the frame then overflowed by one line on every refresh and the
top of it marched down the screen. That is what the eight headers
were. Each panel height is a named constant now, and a test checks
every one of them against what is actually rendered.
3. Lines inside the panels could wrap. A band name, a long status line
or a decoded message made a panel a row taller than the arithmetic
allowed for, with the same result. Every one is drawn on a single
line and ellipsised now. The receiver panel drops its optional parts
instead, keeping the tuner and the flags: "SIMULATED" disappearing off
the end of a narrow line is how somebody comes to believe they are
listening to the air.
4. saunterbrowse's full-screen views did not fill the screen. Nothing
erases the alternate screen between frames -- the cursor is sent home
and the new frame written over the old one -- so pressing t or ? on a
tall window left most of the recording list visible underneath. Both
are wrapped in a layout now, which fills the terminal exactly.
The layout also gives up the receiver panel on a very short terminal,
which it previously had no way to do: on eight rows the smallest frame it
could describe was nine lines.
Testing this by rendering to a wide Console and reading the text back
cannot work -- whether the cursor lands where it should is a property of
the terminal, not of the renderable. So tests/terminal.py runs the
program in a pty, resizes the window underneath it the way a window
manager does, and feeds what it writes to a terminal emulator whose
screen is then read. Every fix above has a test that fails without it,
checked by reverting each one in turn. pyte is a dev dependency and
those tests skip without it; the arithmetic ones need nothing.
Also: t now opens the reader for a capture that carries decoded data
rather than speech, because the decoded panel already told the reader to
press it.
869 -> 949 tests.
A long scan leaves hundreds of recordings, each with a JSON sidecar of
measurements and, where a recogniser heard speech, a transcript. Reading
that meant opening files one at a time and guessing which were worth
playing.
saunterbrowse is a second executable in the same package. Arrow keys move
through the recordings; the transcript of whichever is highlighted fills
the top of the screen, because that is the part anyone actually wants to
read. Enter plays it, handing the file to whichever player is installed
-- the recordings are ordinary WAVs, every desktop already has something
that plays them, and a browser that cannot start would be worse than one
that cannot play. t opens the whole transcript full screen when it is
longer than the panel, and says so rather than cutting the end off
silently. / filters on the frequency, the name, the identification, or
anything that was said, which is the point of it: "was the repeater
mentioned" is a question about content.
Sidecars are read only for the rows on screen, so a directory of ten
thousand recordings opens instantly. Where there is no transcript the
panel says which of the reasons applies -- Morse (decoded, and shown),
data, a bare carrier, or speech never offered to a recogniser -- because
those want different things done about them. It only ever reads.
Two things were only found by driving it through a real terminal.
sys.stdin.read(1) goes through a buffered text wrapper, which in cbreak
mode waits for more bytes than one keypress provides: the program drew its
first frame and then hung, while tests against a stand-in stream object
passed. It reads the file descriptor now, and the tests drive a pty. And
stopping playback signalled only the direct child, so a player that is a
wrapper script kept the sound going with nothing on screen to stop it; the
whole process group is signalled instead, which is what start_new_session
was there for.
man saunterbrowse ships beside man bandsaunter, and the two point at each
other.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016PsWPTweCT6pwxKngvVxcg
Versions are now the release date and a revision within that day, padded to
two digits so they sort as text: 2026-08-21_01.
Neither packaging system accepts that form, so it is converted at the edge
rather than kept as a second version string that could drift out of step:
PEP 440 forbids dashes and underscores in a release segment, and a Debian
version may not contain an underscore at all. The date and revision in
__init__.py are the single source; pyproject reads the converted form, and
the tests check that pip and dpkg both order releases correctly.
packaging/build-deb.sh builds a .deb with plain dpkg-deb. Every dependency
is already in Debian, so apt resolves the lot; the package also blacklists
the DVB-T driver that would otherwise claim the receiver. Deliberately not
debhelper: the payload is pure Python with nothing to compile, and this way
the build needs nothing installed beyond dpkg.
The speech recognisers are not packaged for Debian and can only come from
pip, so they are suggested rather than depended on -- transcription is off
by default and reports plainly when no recogniser is present.
README now documents every dependency with its package name on Debian,
Fedora and Arch, how to let a user reach the receiver, and how to check the
install worked.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Sweeps any set of frequency ranges, records what it finds, and works out
what kind of signal it was.
- Frequency ranges entered by hand or picked from a 135-entry US band plan,
including whole-band and all-CW sweeps that resolve the demodulator per
segment.
- Detection calibrated against the peak-hold detector's own noise statistics,
so the threshold means real margin over static rather than over the floor.
- A content gate: captures are kept only if they carry voice, decodable CW,
or an identified digital keying scheme. Speech is recognised by a pitch
track that drifts, which static cannot imitate.
- Identification of NFM/WFM/AM/SSB, CW with Morse decoded to text, P25, DMR,
NXDN, D-STAR, POCSAG, FLEX, ACARS, AIS, APRS, n-FSK and n-PSK.
- Gapless streaming capture, with the signal path fast enough to keep up in
real time, so recordings play back at the right speed.
- Optional one-file-per-frequency recording with spoken timestamps, and
speech-to-text transcription.
- Menus and command line generated from one settings table, so neither can
offer something the other cannot; settings persist in ~/.config.
367 tests, run against synthetic signals, a built-in receiver simulator, and
real hardware.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The Dust Council