TanagerMethane
Methane Products Overview
Each TanagerMethane item has an automated methane detection algorithm run on it, derived from a matched filter (doi:10.5194/amt-8-4383-2015).
TanagerMethane products are only offered in their orthorectified format. These products can be obtained from the Planet APIs using the TanagerMethane item type.
A Tanager Methane Product is representative of a methane detection attempt on a TanagerScene item. They have the same extent as a TanagerScene. They are represented in the Planet Platform as the TanagerMethane item type.
The Methane QuickLook (MQL) bundle is designed for easy interpretation by methane experts with limited remote sensing knowledge. Within each bundle, you can access multiple imagery assets listed below for their purposes.
Tanager Methane QuickLook Products
Tanager’s Methane QuickLook is a low-latency, derived methane product that reveals point source emission locations and estimates of magnitude in kg/hr for observed plumes. It will be delivered to customers within 72 hours of acquisition, enabling you to identify and take action quickly when emissions are detected.
Methane Plume Metadata
Relevant for ql_ch4_json TanagerMethane assets.
| Parameter | Description | Type |
|---|---|---|
| plume_id | Unique identifier for each plume. The format is <stripid>_<part>. The “part” postfix (For example, A, B, C) identifies multiple plumes captured in the same image in the order they were detected. | string |
| plume_quality | ** This field is used for Methane QuickLook, ql_ch4_json asset-type. ** Qualitative assessment of plume quality captured by a human operator during the plume detection process (good, questionable, or bad). More on the Plume quality classification below. | string |
| plume_provider | Identifies the organization who identified the plume. | string |
| plume_provider_id | Plume ID according to the plume_provider. Planet assigns a new plume ID to match existing naming conventions. | string |
| plume_provider_version | Plume provenance information. This information is not directly useful to customers, but can be used by Planet and the plume_provider to inspect data quality issues. | string |
| datetime | Date and time of the acquisition in Coordinated Universal Time (UTC). | datetime |
| ime | The total kilograms (kg) of methane in a plume above the background concentration at the time of image capture. | float |
| fetch | Plume length, meters (m) | float |
| emission | Quantified emission rate of a plume, estimated using the Integrated Methane Enhancement method. (Duren et al., 2019 - "California's Methane Super-Emitters", Nature) | |
| emission_uncertainty | The uncertainty in an emission rate is derived from uncertainty in IME and wind speed. | |
| wind_speed_avg | Mean wind speed m/s | float |
| wind_speed_std | Standard deviation wind speed m/s | float |
| wind_direction_avg | Wind direction (degrees) | float |
| wind_direction_std | Wind direction standard deviation (degrees) | float |
| wind_source | Wind source from reanalysis. (For example, Openmeteo, HRRR, ERA5) | string |
| strip_id | Strip ID of the Tanager collect used for plume detection. | string |
Plume Quality Classification
Planet classifies detected plumes into three categories: Good, Questionable, and Bad, based on the following criteria:
Good: The plume is unambiguous, with a well-defined shape and minimal artifacts, making it reliable for further analysis.Questionable: The plume is clearly present, but there are issues. For example: irregular shape or retrieval artifacts that could affect the accuracy of quantification. A post-emission QC process will also assess whetherQuestionableplumes are suitable for publishing an emission rate or if only the detection will be reported.Bad: It is unclear whether the detected feature is a plume. However, this is not a final state. After an initial review, a secondary post-emission quality control process is conducted. This review determines whether the detection should be discarded or reclassified asQuestionable.
TanagerMethane Item Type
Tanager Methane — Extent: Global, 2024-01-01T00:00:00Z to present
Description
Tanager Methane Derived Products
TanagerMethane Assets
ql_ch4_json: Preliminary plume locations, length, size in kg/hr and confidence measure indicating the level of visual interpretation certainty, in GeoJSON format.
ortho_ql_ch4: Preliminary 8-bit scaled methane plume intensity in (ppm-m) parts-per-million-meter, in GeoTIFF format. The image will contain an alpha channel indicating pixels with no plume detections.
recent_monthly_mosaic: RGB contextual baselayer from the most recent PlanetScope Global Monthly Mosaic, in GeoTIFF format.
Item Properties
| Field | Description | Data Type |
|---|---|---|
| acquired | Timestamp representing the nominal date and time of acquisition (in UTC). | datetime |
| cloud_percent | The percentage of the image obscured by clouds. | range-integer |
| collection_mode | Imaging sensitivity mode | enum-string |
| geometry | Geospatial extent of image, represented as a geo-json Polygon vs Multi-Polygon. | geometry |
| ground_control | If the image meets the positional accuracy specifications this value will be true. If the image has uncertain positional accuracy, this value will be false. | boolean |
| gsd | The ground sampling distance of the image acquisition. | float |
| id | Provider-specific unique identifier | string |
| item_type | The identifier of the asset | string |
| light_haze_percent | The percentage of the image containing light haze. | range-integer |
| pixel_resolution | Pixel resolution of the ortho product files in meters. | range-float |
| provider | Imagery Provider, as a member of the enum of known providers. | enum-string |
| published | Timestamp representing the first publish of the item id (in UTC). | datetime |
| publishing_stage | Metric for an item's publishing stage. 'Preview' items have not been rectified and may change substantially upon subsequent publish. 'Standard' items are rectified and subject to minimal change upon subsequent publish. 'Finalized' items are rectified and additional changes are not expected. | enum-string |
| quality_category | Metric for image quality. To qualify for 'standard' image quality an image must meet the following criteria: sun altitude greater than or equal to 10 degrees, off nadir view angle less than 20 degrees, and saturated pixels fewer than 20%. If the image does not meet these criteria it is considered 'test' quality. | enum-string |
| satellite_azimuth | Spacecraft off track pointing direction, in degrees (0-360) | range-float |
| satellite_id | human-readable identifier for the satellite(e.g. SSC11, 0c18, RapidEye-2, Sentinel-2A) | string |
| strip_id | Unique Identifier for the underlying RapidEye collect spanning the Item's capture. | string |
| sun_azimuth | Angle from true north to the sun vector projected on the horizontal plane in degrees. | range-float |
| sun_elevation | Elevation angle of the Sun in degrees. | range-float |
| updated | Timestamp representing the last update of the item id (in UTC). | datetime |
| view_angle | Spacecraft across track viewing angle used for imaging. | range-float |