Library · day and night

Does the signal change when the library is busy?

Compare daytime measurements with the preceding night on the same receiver and radio configuration. Recent recordings include the newer library capture profiles. Gaps mean no measurement, never an empty room.

Companion labs in Occupancy

Snapshot built 2026-10-26 23:22. Library clock: Europe/Bratislava. Back to people per minute · The instrument.

Headcounts remain withheld where unsupported. A stronger signal change does not by itself mean more people: seated people, movement, radio delivery and transmitter changes can have different effects.

One week of signal and packet delivery

The upper chart shows hourly medians of amplitude variation, in dB, with the 10th–90th percentile spread of observed minutes. The lower chart shows packet delivery in Hz. Shading marks 22:00–04:00. Points summarise the recorded part of an hour; empty hours stay blank. The spread describes observations, not uncertainty in a headcount.

Day against its preceding night

Day 08:00–20:00; preceding night 22:00–04:00, Europe/Bratislava. The raw difference uses all capture ages. The matched difference always uses age ≥20 minutes and similar packet rates, independently of the chart's age selector. Positive values mean more amplitude variation in daytime; negative values mean less. Night is a clock reference, not a verified empty-room label.

Same receiver, exact profile/channel/width/decoder/record class; age ≥20 min in 5-minute bins; packet rate in quarter-octave bins; ≥5 observations per period per bin and ≥30 matched per period. These are descriptive comparisons. Receivers and adjacent minutes are not independent repeats. Low support means the matched result covers only a small part of the recorded day. Rate matching is coarse; delivery can still differ inside a bin. Fleet injector MAC-prefix scope; a single transmitter is not verified.

Recorded hours for the selected receiver

Library time	Valid / recorded observations	Median (dB)	10th–90th percentile (dB)	Delivery (Hz)

Where are the recent recordings?

The count archive covers only walk-abba-48-night. This view also includes explore-lib-*, with legacy 52-tone and VHT 242-tone records kept separate. A recording can exist without a usable injector signal.