About

The SpatioTemporal Asset Tasking (STAT) API defines a JSON-based web API to query for potential future data and place orders ("tasking") for potential future data from remote sensing data providers (satellite or airborne).

STAT takes much of the work done by the STAC community and applies the lessons learned to this specification. The major departure from STAC is the requirement for uncertainty in many of the STAT properties.For example, a user requesting a data capture can provide a range of dates when they would like to capture. Conversely, a data provider cannot be certain of cloud cover in the future and must return a range of cloud cover probabilities to a user.

The STAT specifications define several new entities: Products, Opportunities, and Orders. These are
derived from the SpatioTemporal Asset Catalog (STAC) specification. Ideally, STAT requests to providers will be ultimately fulfilled via delivery of a STAC Item, so STAT aims to align with STAC core and extensions.

The core STAT specification provides a structure and language to describe Products, Opportunities, and Orders. The process of interacting with a data provider is done through a REST API.

STAT API Description

Core

The core of STAT API includes the /products endpoint and the /orders endpoint.

To know which constraints are available for which product_id, users first explore /products. These constraints can be used to form a POST to the /orders endpoint.

Opportunities

The /opportunities endpoint provides additional functionality on top of core and is designed to be used after /products and before /orders. It allows users more fine-grained control and selection of available tasking opportunities by letting them explore the opportunities which are available for a chosen order configuration. The opportunities are represented in a FeatureCollection, with order specific attributes and values in the feature properties.

Endpoints

STAT APIs follow the modern web API practices of using HTTP Request Methods ("verbs") and the Content-Type header to drive behavior on resources ("nouns") in the endpoints listed below.

The following table describes the service resources available in a STAT API implementation that supports all three of the foundation specifications. Note that the 'Endpoint' column is more of an example in some cases.

Endpoint	Specified in	Returns	Description
`/`	Core	?
`/products`	Core	ProductsCollection	Figure out which constraints are available for which `product_id`
`/orders`	Core	OrdersCollection
POST `/orders`	Core	Order	Order a capture with a particular set of constraints
`/products/{productId}`	Core	Product
`/opportunities`	Opportunities	OpportunitiesCollection
POST `/opportunities`	Opportunities	OpportunitiesCollection	Explore the opportunities available for a particular set of constraints

Conformance Classes

STAT API utilizes OGC API Features Conformance JSON structure. For STAT API, we declare new STAT conformance classes, with the core ones detailed in the table below.

The core STAT conformance classes communicate the conformance JSON only in the root (/) document, while OGC API requires they also live at the /conformance endpoint. STAT's conformance structure is detailed in the core. Note all conformance URIs serve up a rendered HTML version of the corresponding OpenAPI document at the given location.

Conformance Class Table

Name	Specified in	Conformance URI	Description
STAT API - Core	Core		Specifies the STAT Landing page `/`, communicating conformance and available endpoints.
STAT API - Opportunities	Opportunities		Enables request of potential tasking opportunities

See the STAT API Demo

Example Landing Page

The Landing Page will at least have the following conformsTo and links:

{
    "stat_version": "0.1.0",
    "id": "example-stat-api",
    "title": "A simple STAT API Example",
    "description": "This API demonstrated the landing page for a SpatioTemporal Asset Tasking API",
    "conformsTo" : [
        "https://stat-api.example.com/v0.1.0/core"
    ],
    "links": [
        {
            "rel": "conformance",
            "type": "application/json",
            "href": "https://stat-api.example.com/conformance"
        },
        {
            "rel": "service-desc",
            "type": "application/vnd.oai.openapi+json;version=3.0",
            "href": "https://stat-api.example.com/api"
        },
        {
            "rel": "service-doc",
            "type": "text/html",
            "href": "https://stat-api.example.com/api.html"
        },
    ]
}

captaincoordinates/stat-api-spec