3i atlas ata drift rate filter

Sharks, Lee

SPXI instrument · method 0.9 of 87, level 0 (Measurement): Capture Registry (longitudinal observation). An instrument of SPXI, the Semantic Packet for eXchange & Indexing; the whole practice is itemized at spxi.dev/methods.

Capture Registry › capture 3i-atlas-ata-drift-rate-filter-aio-20261104

One record of the canonical Capture Registry (EA-WG-CAPTURES-01), cited at https://www.alexanarch.org/captures/3i-atlas-ata-drift-rate-filter-aio-20261104/. the canonical Capture Registry (version 12.559) · the address page · this card in the gallery · this record as data · table of contents.

AXN:0C00.CAPTURE — this address. Each observation below is one AXN, sealed with its analysis and measures; the identifier names the reading together with the response it reads.
AXN:0C00.CAPTURE.🟤🌋💙👁️🔐💥 — Google AI Overview, 2026-11-04 · sealed observation (SHA-256 c915cb57fbeb7887…)

Machine Reception2026-11-04

3i atlas ata drift rate filter

Originator: Breakthrough Listen and collaborators (the 3I/ATLAS radio searches) · outside the archive (out-universe) · institution · SPXI treatment: partial

BROAD MATCH

no
image

'3I ATLAS ATA DRIFT RATE FILTER', SIGNED OUT, 2026-11-04: 'researchers applied a drift rate filter of 0.05 to 1.5 Hz/s across all frequencies.' Purpose: 'To capture the expected frequency shift (acceleration) caused by the relative motion between 3I/ATLAS and Earth'; the minimum drift at 1336 MHz about 0.15 Hz/s; with frequency blanking, the 74 million hits reduced to about 1.9–2 million before localization and inspection; FAST's maximum of 2 Hz/s. The interval composed with no sign. Six chips, four Berkeley SETI and two IOPscience.

Full record — 2,632 characters, 6 sources

Capture record

captured: 2026-11-04
surface: Google AI Overview
auth state: signed out, incognito
evidence class: paste
PER (historical scalar): 0.5
PER units retained: inst, src
citations read: 6
observation id: OBS-0cb410947c4b
address id: ADDR-a77b955b4cd5

Reading

The innocent reading first. Asked for the ATA drift-rate filter, the Overview gives it as the paper gives it: 0.05 to 1.5 Hz/s at all frequencies, its purpose as the paper states it, the minimum expected drift the paper computes, and the reduction in hits, which matches the press (Astrobiology Web: 'reducing the total number of hits by 97.4%'). It is accurate to the paper's text. The paper's text gives no sign, and neither does the composition; the countertest finds the interval composed and its sign absent.

Findings

THE COUNTERTEST ANSWERED. 3i-atlas-signal-studies-aio-20261104 set this address to record whether the drift interval or its sign is composed. The interval is composed exactly ('researchers applied a drift rate filter of 0.05 to 1.5 Hz/s across all frequencies.'). The sign is not: the paper's sentence carries none, and its Figure 4 places the retained hits at 0 to +1.5 Hz/s (draft §5.1).
THE STATED PURPOSE AND THE EXPECTED SIGN. 'Purpose: To capture the expected frequency shift (acceleration) caused by the relative motion between 3I/ATLAS and Earth, while accounting for uncertainties like potential object rotation or tumbling.' The shift that motion produces on a tone carried by the object is negative in every ATA session: 'A rising range-rate lowers the received frequency, so a positive acceleration gives a negative drift.' (draft §5.1.1, Horizons at the ATA site: 'the drift of a constant tone riding on the object is −0.125 Hz/s at 1075 MHz and −0.19 Hz/s at 1623.75 MHz'). An interval stated without a sign reads as covering the expected shift; the plotted interval holds the opposite sign. The composition reproduces the paper's purpose and its unsigned interval, and the discrepancy between them stays where the paper left it.
WHAT THE FILTER REMOVED, COMPOSED AS RFI CONTROL. 'the calculated minimum drift rate for 3I/ATLAS was approximately 0.15 Hz/s, prompting a middle-ground range to filter out excessive radio frequency interference (RFI) without missing real signals.' The filter is described as removing interference 'without missing real signals'; the class a transmitter on the object would occupy sits outside the plotted interval. The archive's own look at that class in the public July 3 and July 8 sessions (draft §6) found nothing beyond background at the windows examined.
ACCURATE FIGURES. 'reduced the initial set of nearly 74 million narrowband hits (detected via the bliss pipeline) down to about 1.9–2 million hits before further localization and visual inspection.' The figure agrees with the press account's 'reducing the total number of hits by 97.4%'. The FAST note ('(Note: Other observatories like FAST utilized a maximum drift rate up to 2 Hz/s in search routines, corresponding to similar relative acceleration models).') gives a maximum and no sign, and is not checked here.
SMALLEST REPAIR. 'The paper filters hits to drift rates of 0.05–1.5 Hz/s; its Figure 4 shows the retained hits at positive drift only, while a tone fixed on 3I/ATLAS drifts negative throughout the ATA sessions.' COUNTERTEST: '3i atlas ata drift rate sign'.

Analysis analyst prose, not machine text

A composition faithful to its source at the grain of the source's sentence: the interval, the purpose and the counts are the paper's. The paper's own gap passes through intact, the sign that the sentence omits and the figure supplies. What the summarizer can carry is what the published sentence states.

Machine text, verbatim

CAPTURE-TIME VERBATIM RECORD — paste of the results page: the Overview with its source chips, and the organic results · complete as supplied · READ IN FULL 2026-11-04, against the draft's §5.1

[Google AI Overview at the query, signed out and incognito (operator defaults of 2026-10-01 and 2026-10-14). Received 2026-11-04 23:14 EST. The address is the countertest named in 3i-atlas-signal-studies-aio-20261104. The body runs from the 'AI Overview' label to the follow-up offer; the six source chips are kept as pasted. The organic results below the Overview are in the raw transcript.] [QUERENT] 3i atlas ata drift rate filter [SYSTEM] In the SETI Institute's Allen Telescope Array (ATA) search for radio technosignatures from the interstellar object 3I/ATLAS, researchers applied a drift rate filter of 0.05 to 1.5 Hz/s across all frequencies. Berkeley SETI Key Details of the Filter Filtered Range: 0.05 to 1.5 Hz/s Berkeley SETI Purpose: To capture the expected frequency shift (acceleration) caused by the relative motion between 3I/ATLAS and Earth, while accounting for uncertainties like potential object rotation or tumbling. Berkeley SETI +1 Baseline Calculation: At the lowest tuning frequency (1336 MHz), the calculated minimum drift rate for 3I/ATLAS was approximately 0.15 Hz/s, prompting a middle-ground range to filter out excessive radio frequency interference (RFI) without missing real signals. Berkeley SETI Impact: Applying this drift-rate limit—along with initial frequency blanking—reduced the initial set of nearly 74 million narrowband hits (detected via the bliss pipeline) down to about 1.9–2 million hits before further localization and visual inspection. IOPscience +1 (Note: Other observatories like FAST utilized a maximum drift rate up to 2 Hz/s in search routines, corresponding to similar relative acceleration models). IOPscience Would you like more details on how the SETI Institute's ATA study handled RFI blanking or spatial localization with NBeamAnalysis?

Sources (6) as cited, and as the copy produced them

Berkeley SETI third_party
Berkeley SETI
source chip after the opening sentence; the organic result: Sheikh et al., 'A Search for Radio Technosignatures from Interstellar Object 3I/ATLAS with the ...', PDF, seti.berkeley.edu
Berkeley SETI third_party
Berkeley SETI
source chip after 'Filtered Range'
Berkeley SETI third_party
Berkeley SETI (+1)
source chip after 'Purpose'; one further source behind the chip
Berkeley SETI third_party
Berkeley SETI
source chip after 'Baseline Calculation'
IOPscience third_party
IOPscience (+1)
source chip after 'Impact'; one further source behind the chip
IOPscience third_party
IOPscience
source chip after the FAST note; the organic result: Li et al., 'Narrowband Radio Technosignature Search Toward 3I/ATLAS with FAST', 2026

↻ Re-run permalink