Object-wise PSF-leakage correction zeros the same-object slope, not angular leakage; on v2 it raises τ0 by 52%
维护者通常 1 天内回复
还没有人认领这个 Issue。
评估
- 难度
- 5/5
- 预计耗时
- 一周以上
- 新手友好度
- 8/100
- Issue 类型
- 缺陷
- 描述清晰度
- 需要澄清
- 活跃度
- 活跃
- 技术栈
- python
调研方向
The entry point is compute_PSF_leakage and the correction e_leak_corrected = e − α p, which fits α per SNR × size bin from the same-object galaxy–PSF slope. The payload does not name specific test files. Done would require a fit that targets angular leakage, validated on held-out stars, with per-bin α, errors and the global scalar persisted to the catalogue. This is design work and not a first-timer task.
由索引模型根据 Issue 内容生成。
描述
The object-wise PSF-leakage correction (compute_PSF_leakage → e_leak_corrected = e − α p) fits α from the same-object galaxy–PSF slope in SNR × size bins. Angular leakage is measured by ρ/τ at finite separation. These are different quantities, and on v2 they disagree in sign:
- same-object slope (global scalar): −0.0030
- the scalar that would zero first-bin τ0: +0.0058
So on v2, e_leak_corrected raises first-bin τ0 by 52% (5.25e-6 → 8.00e-6); on v1.4.6.3 it lowered τ0 by 59%. A perfect global same-object correction predicts the same 8.00e-6. The implementation itself checks out: the columns reconstruct to 4.6e-14, and the sign convention against stellar models is correct. Mechanism (verified): the same-object slope is a zero-lag mixture, α − β·Cov(p,δp)/Var(p) + η·Cov(p,q)/Var(p), where δp is the PSF ellipticity model error and q = p·δT_PSF/T_PSF the size-error term. The angular α, β, η, together with covariances from held-out stars, reproduce the measured slope: v2 −0.00310 predicted vs −0.00303 measured; v1.4.6.3 +0.0185 vs +0.0164. The size-error term is about −0.010 in both versions. v2's α is 2.5× smaller than v1.4.6.3's, so the sum turns negative. A per-object fit therefore can't isolate α, and a corrected v2 fiducial needs a fit that targets angular leakage.
Consequence: for v2, the _leak_corr columns are not a validated fiducial, so raw E is the reference.
Proposed:
- make the target of
compute_PSF_leakageexplicit (object-wise vs angular on declared scales), and validate a correction on held-out stars before treating it as fiducial; - persist the fit diagnostics (per-bin α, errors, global scalar) with the catalogue;
- label these columns as object-wise corrections in headers and docs.
Related: #382 (the trend-fit 1/σ⁴ weighting, negligible here at 5e-10), #413 (full a_ij / spin components).
Claude (Opus 5.5) on behalf of Cail
- 主要语言
- Python
- 星标
- 2
- 派生
- 5
- 平均合并
- 1 天 1 小时
- 30 天内合并 PR
- 26
环境准备
- 提供 Dockerfile 或 Docker Compose 文件
- 没有 Pull Request 模板
- 阅读贡献指南
从这里开始
- 先读完整个 Issue，再读项目的贡献指南。
- 在 Issue 下留言说明你要接手 —— 这能避免两个人做同样的事。
- Fork 仓库，在一个分支上完成修改。
- 提交 Pull Request，并在描述里引用这个 Issue 编号。
CosmoStat/sp_validation 的其他 Issue
-
难度 2/5 1-3 小时 新手友好度 74/100
CosmoStat/sp_validation#315 ·
维护者通常 1 天内回复
-
难度 2/5 半天 新手友好度 65/100
CosmoStat/sp_validation#272 ·
维护者通常 1 天内回复
-
Decide whether the catalogue cuts on ShapePipe's external_paired_fraction可能已有人在做 @cailmdaley 今天认领。 未关闭
难度 5/5 一周以上 新手友好度 25/100
CosmoStat/sp_validation#444 ·
维护者通常 1 天内回复
-
难度 4/5 3-5 天 新手友好度 42/100
CosmoStat/sp_validation#443 ·
维护者通常 1 天内回复
-
难度 4/5 3-5 天 新手友好度 38/100
CosmoStat/sp_validation#435 ·
维护者通常 1 天内回复
查看 CosmoStat/sp_validation 的全部 Issue
相似的 Issue
-
难度 2/5 1-3 小时 新手友好度 68/100
-
难度 2/5 1-3 小时 新手友好度 70/100
维护者通常 2 天内回复
-
难度 2/5 1-3 小时 新手友好度 62/100
维护者通常 2 天内回复
-
bug
难度 2/5 1-3 小时 新手友好度 82/100
developmentseed/titiler-cmr#278 ·
维护者通常 1 天内回复
-
难度 2/5 1-3 小时 新手友好度 82/100
维护者通常 2 天内回复