Source data (PGDA product 78, Site01)

This page states the facts about the source data used by the Site01 result. It draws only on the frozen source manifest research/sources/pgda78-site01.manifest.json and on the code that reads it. Items the manifest does not record are marked as not recorded.

Source product

Field	Value (from the manifest)
Witness identifier	`pgda78-site01`
Status	`SOURCE_FROZEN`
Title	PGDA product 78: LOLA 5 m/pix polar DEMs and derived products, Site01 (Connecting ridge)
Publisher	NASA GSFC Planetary Geodesy Data Archive (PGDA)
Landing page	`https://pgda.gsfc.nasa.gov/products/78`

The manifest lists two citations for the upstream publications, both with DOIs:

Barker, M.K., Mazarico, E., Neumann, G.A., Smith, D.E., Zuber, M.T., Head, J.W. (2021). Planetary and Space Science 203, 105119. DOI 10.1016/j.pss.2020.105119.
Mazarico, E., Neumann, G.A., Smith, D.E., Zuber, M.T., Torrence, M.H. (2011). Icarus 211, 1066–1081. DOI 10.1016/j.icarus.2010.10.030.

These DOIs identify the upstream publications. They do not identify LunarTrace software or results. The manifest does not state that the cited papers’ findings are reproduced here.

Roles used by the method

The manifest maps roles to entries. The method uses these roles.

Role	File	Native meaning (manifest `native_semantics`)
`slope`	`Site01_final_adj_5mpp_slp.tif`	Slope, degrees
`slope_rms`	`Site01_final_adj_5mpp_slperr.tif`	Slope RMS uncertainty, degrees
`roi_shp`, `roi_shx`, `roi_dbf`, `roi_prj`	`Site01_ROIs.shp`, `.shx`, `.dbf`, `.prj` (members of `Site01_ROIs.tgz`)	ROI polygons, 7 polygons
`roi_archive`	`Site01_ROIs.tgz`	Archive containing the four ROI sidecars

The manifest records other roles that the method does not read: surface_height (surf), surface_height_rms (toterr), ldec_count (ldec) and readme. Their meanings are given in the manifest’s native_semantics block. The manifest describes toterr as total Z uncertainty in metres and surf as surface height in metres. The method does not use them.

Grid and coordinate reference system

The manifest’s native_semantics block records the following.

Grid. 5 m per pixel, GMT pixel registration (node_offset=1), 3200 × 3200 cells.
Affine transform. $(5, 0, -19000, 0, -5, -4000)$ .
CRS. +proj=stere +lat_0=-90 +lat_ts=-90 +lon_0=0 +x_0=0 +y_0=0 +R=1737400 +units=m, with the manifest note “MOON_ME / DE421 per README”.
Reference frame. The README describes the frame as MOON_ME with ephemeris DE421.
Registration. Pixel-registered X and Y identify pixel centres. For column $c$ and row $r$ , the centre is $x = x_0 + 5(c + \tfrac12)$ and $y = y_0 - 5(r + \tfrac12)$ , where $x_0 = -19000$ and $y_0 = -4000$ (see Method, equation 1).

The primary code requires the CRS to be proj=stere, lat_0=-90, lon_0=0, x_0=0, y_0=0 and sphere radius $R = 1737400$ m. It checks this for both rasters and for the .prj file (_require_south_polar_stereographic, src/lunartrace/science/slope_quality.py). The projection is a polar stereographic projection on a lunar sphere. Its scale factor varies with position, so cells are not equal in area (see Limitations).

NoData and value ranges

Declared NoData. NaN. The manifest records zero NaN cells observed in the two slope rasters (slp and slperr).
Loader behaviour. A declared non-NaN NoData value would be replaced by NaN on load (load_grid, slope_quality.py). The Site01 NoData declaration is NaN, so no replacement occurs.
Validity. The manifest’s zero-NaN observation does not replace the per-cell checks. The method applies the validity predicates to every cell (see Method, equations 2–4).

ROI polygons

The manifest records the ROI archive as “Site01_ROIs: 7 polygons”. Its native_semantics note reads, “regionProps avg illumination > 70%”. The manifest states that this description is taken from the archive symlink target name Site01_final_adj_5mpp_01_regionProps_avgillGT070.gmt, and that the symlink was excluded at extraction. This project did not verify the illumination criterion. It is recorded here as the manifest’s description.

The ROI polygons are in metres in the same polar stereographic CRS. The manifest does not describe whether any polygon has interior rings. The method rejects any polygon with holes, so a shapefile with holes fails closed (load_rois).

The method documentation describes two features of these rings. ROI 5 has two lobes that meet at a pinch vertex, and ROI 6 has a collapsed out-and-back spur forming a one-cell-wide filament (docs/guide/method.md). The closed rule is designed for these features (see Method, ROI membership).

Content-addressed custody

The manifest records the local store and its layout.

Store. Local, outside Git; location configured via LUNARTRACE_SOURCE_STORE. The store is single-copy. The manifest notes that durable custody is a residual.
Layout. cas/sha256/<2>/<64>, where the 64-character hex digest is the file’s SHA-256.
Resolution. The STUDY plane resolves each entry’s cas path under the store and re-verifies its digest before use (see Verification).

Each entry carries a fetched_at timestamp (2026-10-10, UTC) and HTTP metadata from the download. These fields describe the fetch. They do not describe the currentness of the upstream product.

Frozen entries

These are the byte identities the method pins. Sizes are in bytes.

Name	Role	Size	SHA-256
`Site01_final_adj_5mpp_slp.tif`	`slope`	40 980 776	`3a90035a4946b4a04b7332c52f0b2b1cff71648bd8c105e14d8a7e15c6bcfe8e`
`Site01_final_adj_5mpp_slperr.tif`	`slope_rms`	40 980 810	`52bc3b239f61605e6bb98bab6d6b17acd22389c59e57336862157f2fbd643a33`
`Site01_ROIs.shp`	`roi_shp`	10 204	`7becad19a382db4f14ec33dd652ae37e18cc58d9c9236afa75679c70c1d7a099`
`Site01_ROIs.shx`	`roi_shx`	156	`9ec4f272bf4c431be3da8322d695549f0f4d3a6a0e7b8f367969fcfcb88b0319`
`Site01_ROIs.dbf`	`roi_dbf`	441	`953b9d25f6bc0309eb07722c9e3d90243b47cbead176b8a5d1c306f0fad0dd80`
`Site01_ROIs.prj`	`roi_prj`	352	`d9d9a069d1353411f290d100d6e1cce79878e6efdf9f9bb43450df675f49db15`

The manifest also records the .tgz archive, the README and the surf, toterr and ldec rasters. They are omitted from the table because the method does not read them.

The manifest records one rejected entry. README_LOLA_5mpp.txt returned an HTML “Not Found” page with HTTP 200, so it was replaced by the README at /data/LOLA_5mpp/README. The rejected blob remains in the store as evidence and is not a source.

Rights and redistribution

Rights status. The frozen manifest records UNVERIFIED: PGDA states no licence for product 78, and the NASA-produced data is presumed, not confirmed, to be U.S. Government work. The owner decided on 2026-10-14 not to redistribute the bytes, so no rights claim is needed.
How to obtain the bytes. Run task sources:fetch with LUNARTRACE_SOURCE_STORE set. It downloads each manifest entry from its PGDA URL, extracts the ROI shapefile members from the archive, and admits each file only when its size and SHA-256 match the manifest. A changed upstream file fails closed. task sources:fetch -- --check verifies an existing store without network access. The raster files are not included in this repository or documentation.

Limits of what the manifest establishes

A frozen witness fixes the exact bytes that were fetched. It does not establish that they are the latest upstream version. An upstream reissue would be a new witness.
The digest of the ROI shapefile covers the .shp file. The other sidecars are pinned in the STUDY and oracle paths. The manifest and the primary loader do not describe every member file in the same way (see Verification).
The manifest records a single site, Site01. The method has no multi-site coverage.