canvodpy 0.2.2

Python ecosystem for GNSS-Transmissometry canopy VOD retrievals

canvodpy

Umbrella package for the canVODpy GNSS-Transmissometry ecosystem.

Part of the canVODpy ecosystem.

Overview

canvodpy is the unified entry point for deriving canopy Vegetation Optical Depth (VOD) from GNSS Signal-to-Noise Ratio (SNR) observations. It orchestrates the full pipeline from raw RINEX/SBF files through ephemeris augmentation, hemispheric gridding, and VOD retrieval via the Tau-Omega radiative transfer model.

Four API levels are available to match your workflow:

Level	Style	Entry point	Use case
L1	Convenience	process_date(), Site	Quick exploration, notebooks
L2	Fluent	FluentWorkflow().read().augment().grid().vod()	Scripted pipelines
L3	Low-level	Direct subpackage access	Full control, custom integrations
L4	Functional	read_rinex(), augment_with_ephemeris(), ...	Airflow / orchestrators

Installation

# Installs canvodpy + all 11 sub-packages
uv pip install canvodpy

Quick Start

L1: Convenience (fastest path)

from canvodpy import Site

site = Site("Rosalia")
result = site.process_date("2025001")

L2: Fluent workflow

import canvodpy

result = (
    canvodpy.workflow("Rosalia")
    .read("2025001")
    .augment()
    .grid()
    .vod("canopy_01", "reference_01")
    .result()
)

L3: Direct subpackage access

from canvod.readers import Rnxv3Obs
from canvod.auxiliary import AuxDataAugmenter
from canvod.grids import create_hemigrid
from canvod.vod import TauOmegaZerothOrder
from canvod.store import GnssResearchSite

L4: Functional API (Airflow-compatible)

from canvodpy import read_rinex, augment_with_ephemeris, assign_grid_cells

ds = read_rinex("path/to/ROSA01TUW_R_20250010000_01D_01S_AA.rnx")
ds = augment_with_ephemeris(ds, agency="COD")
ds = assign_grid_cells(ds, grid_type="equal_area", resolution=2.0)

Included Packages

Installing canvodpy provides access to all 11 sub-packages:

Package	Namespace	Role
canvod-readers	canvod.readers	RINEX v2/v3 and SBF binary readers → xarray.Dataset
canvod-auxiliary	canvod.auxiliary	Ephemeris augmentation (SP3/CLK and broadcast)
canvod-grids	canvod.grids	Equal-area hemisphere grid operations
canvod-store	canvod.store	Icechunk/Zarr versioned storage layer
canvod-store-metadata	canvod.store_metadata	FAIR/DataCite/ACDD/STAC metadata lifecycle
canvod-vod	canvod.vod	Tau-Omega VOD retrieval algorithms
canvod-viz	canvod.viz	2D polar and 3D interactive visualization
canvod-utils	canvod.utils	Pydantic configuration models, shared utilities
canvod-ops	canvod.ops	Composable preprocessing operations pipeline
canvod-virtualiconvname	canvod.virtualiconvname	Canonical GNSS-T filename parser and validator
canvod-audit	canvod.audit	Three-tier verification and regression suite

Platform Support

Platform	Status	Notes
Linux	Full support	Recommended for production
macOS	Full support	Fully tested
Windows	WSL only	Native not supported (reserved aux name)

Configuration

Site and processing configuration lives in YAML files (not committed):

just config-init      # create config/processing.yaml + sites.yaml + sids.yaml
just config-validate  # validate against Pydantic models

Optional NASA CDDIS access (for SP3/CLK ephemeris downloads):

# config/processing.yaml
credentials:
  nasa_earthdata_acc_mail: [e-mail]

Without credentials, canvodpy uses ESA GSSC (no authentication required).

Documentation

Full documentation: nfb2021.github.io/canvodpy

Development

See the main repository for workspace development setup.

uv sync                    # install all workspace deps
just check                 # lint + format
just test                  # run all tests

License

Apache License 2.0