diff --git a/CHANGELOG.md b/CHANGELOG.md index e57a0c9..623362c 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0 ### Deprecated +- `sar:product_type` in favor of `product:type` + ### Removed ### Fixed diff --git a/README.md b/README.md index a1a7f28..67d256e 100644 --- a/README.md +++ b/README.md @@ -36,7 +36,7 @@ To describe frame start and end times, use the | sar:frequency_band | string | **REQUIRED.** The common name for the frequency band to make it easier to search for bands across instruments. See section "Common Frequency Band Names" for a list of accepted names. | | sar:center_frequency | number | The center frequency of the instrument, in gigahertz (GHz). | | sar:polarizations | \[string] | **REQUIRED.** Any combination of polarizations. | -| sar:product_type | string | **REQUIRED.** The product type, for example `SSC`, `MGD`, or `SGC` | +| sar:product_type | string | ***DEPRECATED** in favor of [`product:type`](https://github.com/stac-extensions/product).* The product type, for example `SSC`, `MGD`, or `SGC` | | sar:resolution_range | number | The range resolution, which is the maximum ability to distinguish two adjacent targets perpendicular to the flight path, in meters (m). | | sar:resolution_azimuth | number | The azimuth resolution, which is the maximum ability to distinguish two adjacent targets parallel to the flight path, in meters (m). | | sar:pixel_spacing_range | number | The range pixel spacing, which is the distance between adjacent pixels perpendicular to the flight path, in meters (m). Strongly RECOMMENDED to be specified for products of type `GRD`. | @@ -61,23 +61,6 @@ for instance for `HH+HV` add both `HH` and `HV`. **Important:** In the `properties` of a STAC Item `sar:polarizations` must be a set with unique elements. In assets `sar:polarizations` can contain duplicate elements and, if possible, the polarizations must appear in the same order as in the file. -#### sar:product_type - -The product type defines the type of processed data contained in the assets. A list of suggestions include: - -| sar:product_type | Type | Description | -| ----------------- | --------- | ----------- | -| SSC | complex | Single-look Slant-range Complex image (standard SLC) | -| MGD | amplitude | Multilooked Ground-range Detected image | -| GRD | amplitude | Multilooked Ground-range Detected image (used by Sentinel-1) | -| GEC | amplitude | Geocoded Ellipsoid Corrected image | -| GTC | amplitude | Geocoded Terrain Corrected image | -| RTC | amplitude | Geocoded Radiometrically Terrain Corrected image | -| SGC | complex | Single-look Ground projected Complex image | -| SLC | complex | Single-look Ground projected Complex image (used by Sentinel-1) | - -This can vary by data provider, who all may use slightly different names. Sentinel-1 for instance uses `GRD`, which is the same as the more general `MGD` and `SLC` instead of `SGC`. - ### Common Frequency Band Names The `sar:frequency_band` is the name that is commonly used to refer to that band's spectral @@ -94,6 +77,30 @@ properties. The table below shows the common name based on the wavelength and fr | K | 1.1 - 1.7 | 18 - 26.5 | | | Ka | 0.75 - 1.1 | 26.5 - 40 | | +### Product type + +The product type for SAR data defines the type of processed data contained in the assets. +A list of suggestions for [`product:type`](https://github.com/stac-extensions/product) include: + +| product:type | Type | Description | +| ------------ | --------- | ----------- | +| SSC | complex | Single-look Slant-range Complex image (standard SLC) | +| MGD | amplitude | Multilooked Ground-range Detected image | +| GRD | amplitude | Multilooked Ground-range Detected image (used by Sentinel-1) | +| GEC | amplitude | Geocoded Ellipsoid Corrected image | +| GTC | amplitude | Geocoded Terrain Corrected image | +| RTC | amplitude | Geocoded Radiometrically Terrain Corrected image | +| SGC | complex | Single-look Ground projected Complex image | +| SLC | complex | Single-look Ground projected Complex image (used by Sentinel-1) | + +This can vary by data provider, who all may use slightly different names. +Sentinel-1 for instance uses `GRD`, which is the same as the more general `MGD` and `SLC` instead of `SGC`. + +**Note:** +- v1.0 of the extension did require `sar:product_type`. +- v1.1 deprecates `sar:product_type` and it's not required any longer, but `product:type` is **strongly recommended**. +- v2.0 will require `product:type` as part of this extension and remove `sar:product_type`. + ### Date and Time In SAR, you usually have frame start and end time. To describe this information it is recommended to use the [Date and Time Range fields](https://github.com/radiantearth/stac-spec/blob/master/item-spec/common-metadata.md#date-and-time-range). diff --git a/examples/envisat.json b/examples/envisat.json index 978daf9..08399a2 100644 --- a/examples/envisat.json +++ b/examples/envisat.json @@ -2,7 +2,8 @@ "type": "Feature", "stac_version": "1.0.0", "stac_extensions": [ - "https://stac-extensions.github.io/sar/v1.0.0/schema.json" + "https://stac-extensions.github.io/sar/v1.0.0/schema.json", + "https://stac-extensions.github.io/product/v0.1.0/schema.json" ], "id": "sar-envisat-example", "properties": { @@ -26,7 +27,7 @@ "sar:looks_azimuth": 4, "sar:frequency_band": "C", "sar:center_frequency": 5.331, - "sar:product_type": "GM1_1P" + "product:type": "GM1_1P" }, "geometry": { "type": "Polygon", diff --git a/examples/sentinel-1.json b/examples/sentinel-1.json index e5db7e7..f51407c 100644 --- a/examples/sentinel-1.json +++ b/examples/sentinel-1.json @@ -2,7 +2,8 @@ "type": "Feature", "stac_version": "1.0.0", "stac_extensions": [ - "https://stac-extensions.github.io/sar/v1.0.0/schema.json" + "https://stac-extensions.github.io/sar/v1.0.0/schema.json", + "https://stac-extensions.github.io/product/v0.1.0/schema.json" ], "id": "sentinel-1-example", "properties": { @@ -27,7 +28,7 @@ "sar:looks_equivalent_number": 2.7, "sar:frequency_band": "C", "sar:center_frequency": 5.405, - "sar:product_type": "GRD" + "product:type": "GRD" }, "geometry": { "type": "Polygon", diff --git a/json-schema/schema.json b/json-schema/schema.json index 0cb85bf..9ab00f4 100644 --- a/json-schema/schema.json +++ b/json-schema/schema.json @@ -34,8 +34,7 @@ "required": [ "sar:instrument_mode", "sar:frequency_band", - "sar:polarizations", - "sar:product_type" + "sar:polarizations" ], "properties": { "sar:polarizations": {