Roadmap#

Note

PYSTILT is alpha software (v0.1.0a1). The public API may change while the package settles. No backward compatibility guarantees before v1.0.

Current status#

The core transport is stable and exercised by the test suite:

  • HYSPLIT trajectory and footprint generation

  • Numerical parity with uataq/stilt (R-STILT) at rtol=1e-7 per cell

  • Local and SLURM execution paths

  • Simulation registry (skip-existing, status tracking)

  • Observation layer for science-facing workflows

Active development is focused on finishing the core runtime simplification (plan 036: simulation registry and bounded index) before expanding into new science or packaging features.

Execution and orchestration (from stiltctl)#

stiltctl is a cloud-native STILT orchestration system. PYSTILT borrows its thin CLI → model → worker call path: no separate service facade, no broad queue abstraction — just a direct connection from the CLI to Model and from Model to the execution backend.

Feature

Status

Pull-mode queue workers (stilt pull-worker)

Implemented

Long-lived streaming mode (stilt serve)

Implemented

PostgreSQL-backed simulation registry for distributed coordination

Implemented

Scene-based submission grouping (stilt register --scene-id)

Implemented

Thin CLI → Model → worker call path

Implemented

Kubernetes worker deployment

Partial

Cloud object store outputs (GCS, S3)

In scope

Column and satellite science (from X-STILT)#

X-STILT extends STILT for column and slant-path satellite retrievals. PYSTILT absorbs X-STILT’s observation-layer design and column-weighting concepts. Full X-STILT feature parity is not a goal.

Feature

Status

stilt.observations layer (Observation, Scene, PointSensor, ColumnSensor)

Implemented

Column receptor support

Implemented

Vertical operator particle transforms (averaging kernel / pressure weighting)

Implemented

First-order lifetime decay transform

Implemented

Declarative per-footprint transforms in config YAML

Implemented

Slant-column receptor support

In scope (pending HYSPLIT vertical-coordinate validation)

Additional transform types

In scope

Specific sensor adapters (OCO-2/3, TROPOMI, TCCON)

Deferred

Inventory coupling and background estimation

Deferred

Future plans#

The following work is planned but blocked on stabilizing the current runtime surface first:

  • Spatial-target and footprint aggregation: ergonomic projection/aggregation bridge between footprints and non-rectilinear flux grids.

  • Slant receptor geometry: satellite-geometry receptors once HYSPLIT vertical-coordinate behavior is validated.

  • Observation-layer maturation: specific sensor adapters, weighting pipelines, and chemistry hooks after the observation foundation proves stable.