REAL OJAI / CA-33 GEOSPATIAL INPUTS — 20 October 2026

Primary files for the public compiler/site:
  ojai-ca33-dem.f32         512x512 little-endian Float32, row-major
  grid-manifest.json       Bounds, transform, CRS, datum, exact request, hashes
  ojai-ca33-naip.jpg        1024x1024 RGB aligned requested extent
  imagery-manifest.json    Exact imagery request, checksum, dates, attribution
  corridor-roads-public.json 6 clipped license-matched Caltrans SHN features
  epqs-spotchecks.json      16 source-backed terrain spot checks and receipts

Projection: EPSG26911, NAD83 / UTM zone11N, horizontal meters.
Terrain vertical reference: NAVD88 meters, according to intersecting primary
source catalog records. Output is a dynamic multi-resolution mosaic; contributor
rasters were not explicitly locked per pixel. Requested export sampling is
15.446957781427955 m, not native source resolution. GeoTIFF is pixel-area; use
half-pixel offsets for sample centers. Actual served bounds in manifest are
authoritative and differ from requested WGS84 bounding box due to aspect ratio.

Terrain provenance: USGS3DEP ImageServer; GeoTIFF and source metadata retained.
The exact original GeoTIFF SHA256 is
b7c5c094915a628b74c1a0d72fcd612c6458b45f233256e849691c636ec61fcb
The derived .f32 SHA256 is
996a01f14f93cc2d27a9e3386c5cef4558a27d3be68ffa1023ff08900714c0d1
USGS3DEP is public domain/free of charge/without use restrictions.
https://www.usgs.gov/3d-elevation-program/about-3dep-products-services

Dates: retrieval/publication date is not capture date. DEM source catalog includes
2018 primary lidar-derived data and2023 coarse surfaces. EPQS preserves provider
AcquisitionDate values verbatim, including the imprecise string '6/0/2018'.
All nine primary NAIP tile records intersecting served extent list2022-05-13;
this is a nominal catalog acquisition, not a per-pixel contributor lock.
NAIP imagery is public domain. Credit USGS, USDA, The National Map.

Caltrans: final public routes come from CHhighway/SHN_Lines/FeatureServer/0,
linked directly by the Data.CA.gov State Highway Network Lines catalog. That
catalog states Creative Commons Attribution and no restrictions on public use.
https://data.ca.gov/@caltrans/state-highway-network-lines
Routes were server-simplified at maxAllowableOffset10m and clipped locally to
the DEM rectangle. Only identifiers and cartographic geometry are retained.
This is not lane geometry, road elevation, a surveyed route, or live road status.
Earlier engineering receipt caltrans-corridor-roads.json came from the RH service
and includes unnecessary staff editor attributes. Do not serve that raw file.
Use corridor-roads-public.json and the minimal caltrans-shn-licensed-source.json.

SAME-SOURCE SPOT CHECKS:
16 exact raster pixel centers, regular4x4 distributed grid. USGS GeometryServer
projected actual UTM centers to EPSG4326; the request and returned coordinate
arrays are retained. EPQS queries use those exact projected points. Every raw
EPQS response is retained and hashed in epqs/00.json through15.json.
DEM minus EPQS RMS:0.6362206850769951m; median signed:0.021629333253898153m;
maximum absolute:1.782958984375m.
These are service-sampling differences, NOT independent absolute accuracy.
EPQS and raster export can share source rasters. No survey checkpoints used.

OPTIONAL PRESENTATION FIDELITY BENCHMARK:
benchmark_terrain.py measures downsample/reconstruction deviation from served
512x512 raster, not ground truth. terrain-fidelity-results.json preserves results.
128x128 retains6.25% of height samples and reconstructs with RMS3.9365196828m
relative to the original sampled raster. Narrow features can be suppressed.
Single-run CPU diagnostic timings are not production performance benchmarks.

REPRODUCTION:
python extract_dataset.py --output NEW_EMPTY_OUTPUT_DIRECTORY
Verifies retained GeoTIFF hash, TIFF transform and derived float32 checksum.
Dependencies actually used: Python3.12.14; NumPy2.3.5; Pillow12.3.0.
No pyproj dependency: coordinate transformation was performed by public USGS
GeometryServer and source responses retained. Dynamic requests may change in
future; exact reproduction uses retained and hashed input bytes.

The initial DEM request accidentally prefixed the interpolation token with '+'.
A corrected RSP_BilinearInterpolation request was fetched and verified byte-
identical to the retained GeoTIFF; final manifest uses corrected request URL.
The NAIP catalog request was corrected to an explicit JSON projected envelope;
retained catalog now contains nine California tiles, not an unfiltered response.

No independent image/terrain feature registration, ground accuracy, geodetic
integrity, real-time navigation, or freshness guarantee has been established.
