{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2018:7ZCIFFHWN4436DTTK3FQ4TI5KO","short_pith_number":"pith:7ZCIFFHW","schema_version":"1.0","canonical_sha256":"fe448294f66f39bf0e7356cb0e4d1d53aaba05d8d54a89d6fe1337015e98a620","source":{"kind":"arxiv","id":"1811.08259","version":2},"attestation_state":"computed","paper":{"title":"Extracting the Spectrum by Spatial Filtering","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.ao-ph"],"primary_cat":"physics.flu-dyn","authors_text":"Hussein Aluie, Mahmoud Sadek","submitted_at":"2018-11-20T14:17:48Z","abstract_excerpt":"We show that the spectrum of a flow field can be extracted within a local region by straightforward filtering in physical space. We find that for a flow with a certain level of regularity, the filtering kernel must have a sufficient number of vanishing moments in order for the \"filtering spectrum\" to be meaningful. Our derivation follows a similar analysis by Perrier et al. 1995 for the wavelet spectrum, where we show that the filtering kernel has to have at least $p$ vanishing moments in order to correctly extract a spectrum $k^{-\\alpha}$ with $\\alpha < p+2$. For example, any flow with a spec"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1811.08259","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2018-11-20T14:17:48Z","cross_cats_sorted":["physics.ao-ph"],"title_canon_sha256":"cef0b265bcedc739b532d41646fbf4b09c35c988aeacb1552ca93e4663a7a119","abstract_canon_sha256":"a713e71462407a8ae35d30bc8b89a4dfe65dd8034b62959ded266e50eee85106"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:59:22.001211Z","signature_b64":"466v6eubY1Ox92hGs5goImyKmQ7JbxpEJ4mysE1VlKK2GIIcGfJO9m7741B3DW5d4ICZM4ze9dc8ghhtTkDoAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fe448294f66f39bf0e7356cb0e4d1d53aaba05d8d54a89d6fe1337015e98a620","last_reissued_at":"2026-05-17T23:59:22.000786Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:59:22.000786Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Extracting the Spectrum by Spatial Filtering","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.ao-ph"],"primary_cat":"physics.flu-dyn","authors_text":"Hussein Aluie, Mahmoud Sadek","submitted_at":"2018-11-20T14:17:48Z","abstract_excerpt":"We show that the spectrum of a flow field can be extracted within a local region by straightforward filtering in physical space. We find that for a flow with a certain level of regularity, the filtering kernel must have a sufficient number of vanishing moments in order for the \"filtering spectrum\" to be meaningful. Our derivation follows a similar analysis by Perrier et al. 1995 for the wavelet spectrum, where we show that the filtering kernel has to have at least $p$ vanishing moments in order to correctly extract a spectrum $k^{-\\alpha}$ with $\\alpha < p+2$. For example, any flow with a spec"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1811.08259","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"aliases":[{"alias_kind":"arxiv","alias_value":"1811.08259","created_at":"2026-05-17T23:59:22.000847+00:00"},{"alias_kind":"arxiv_version","alias_value":"1811.08259v2","created_at":"2026-05-17T23:59:22.000847+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1811.08259","created_at":"2026-05-17T23:59:22.000847+00:00"},{"alias_kind":"pith_short_12","alias_value":"7ZCIFFHWN443","created_at":"2026-05-18T12:32:13.499390+00:00"},{"alias_kind":"pith_short_16","alias_value":"7ZCIFFHWN4436DTT","created_at":"2026-05-18T12:32:13.499390+00:00"},{"alias_kind":"pith_short_8","alias_value":"7ZCIFFHW","created_at":"2026-05-18T12:32:13.499390+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO","json":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO.json","graph_json":"https://pith.science/api/pith-number/7ZCIFFHWN4436DTTK3FQ4TI5KO/graph.json","events_json":"https://pith.science/api/pith-number/7ZCIFFHWN4436DTTK3FQ4TI5KO/events.json","paper":"https://pith.science/paper/7ZCIFFHW"},"agent_actions":{"view_html":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO","download_json":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO.json","view_paper":"https://pith.science/paper/7ZCIFFHW","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1811.08259&json=true","fetch_graph":"https://pith.science/api/pith-number/7ZCIFFHWN4436DTTK3FQ4TI5KO/graph.json","fetch_events":"https://pith.science/api/pith-number/7ZCIFFHWN4436DTTK3FQ4TI5KO/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO/action/timestamp_anchor","attest_storage":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO/action/storage_attestation","attest_author":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO/action/author_attestation","sign_citation":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO/action/citation_signature","submit_replication":"https://pith.science/pith/7ZCIFFHWN4436DTTK3FQ4TI5KO/action/replication_record"}},"created_at":"2026-05-17T23:59:22.000847+00:00","updated_at":"2026-05-17T23:59:22.000847+00:00"}