SkySat
SkySat is one of the satellite constellations operated by Planet. It is now possible to purchase, order and access SkySat archive data using Sentinel Hub (SH).
Discover samples of SkySat, free to all active Planet users and Sentinel Hub users with a paid subscription: Sandbox Data for SkySat.
About SkySat data
Highlights
- capacity to image an area of interest up to 10x daily
- 0.5 - 0.9 m pixel size (resampled to 0.5 m)
- Blue, Green, Red, Near Infrared, and Panchromatic bands
Mission information
SkySat satellite constellation consists of 21 satellites, which were launched between 2013 and 2020. The satellites are based on a CubeSat concept but are a bit bigger comparing to the PlanetScope's satellites. Because of its rapid revisit time, this data is suitable to monitor fast changes on earth's surface. However, note that the data acquisition must be tasked, data is not acquired systematically. If you are interested in tasking SkySat imagery, please contact Planet.
Basic facts
| Property | Info |
|---|---|
| Spatial resolution | 0.5 m (resampled) |
| Sensor | CMOS Frame Camera with Panchromatic and Multispectral halves. Blue, Red, Green, Near-Infrared, and Panchromatic band |
| Revisit time | Capacity to image up to 10x a day but acquisitions must be tasked (ordered). |
| Spatial coverage | global |
| Data availability | 2014 -> now |
| Available measurements | Top of the atmosphere reflectance, surface reflectance. |
More information:
- https://developers.planet.com/docs/data/skysat/
- https://assets.planet.com/docs/Planet_Combined_Imagery_Product_Specs_letter_screen.pdf
Attribution and use
The SkySat products are released under the license available here.
Purchasing SkySat archive data
Note: If you already have your Planet's api key that has access to SkySat archive, you can skip this section and continue with Ordering SkySat Data.
The process of purchasing of archive SkySat data in Sentinel Hub goes as follows:
- Check the pricing and conditions. If you would like to buy bigger area send us an e-mail and we will prepare a custom offer.
- Go to the "Billing" section in your SH Dashboard and buy the SkySat plan.
- You will get an invitation from Planet to sign EULA, after which you will receive your Planet's api key.
Once you have your Planet's api key you can proceed to Ordering SkySat Data.
Additional info
- Vouchers for non-commercial use available, sponsored by ESA, follow this link.
- Volume discounts possible for large users. Contact us.
- Existing Planet users can use the data through Sentinel Hub using their own credentials.
- If you are interested in tasking SkySat imagery, please contact Planet.
Ordering SkySat Data
For ordering of SkySat data you will need your Planet api key. To order SkySat data, please use our Third Party Data Import API. Minimum individual order is 25 km2. You can order smaller areas, however, you will be billed for the minimum area. If you order a multipolygon, the minimum billed area applies to the entire multipolygon and not per polygon. Please note that you can only order the already acquired data, while tasking your own SkySat data acquisitions is not currently possible through Sentinel Hub. You can check the cost of your order before confirming it.
itemType parameter
SkySat data are available as SkySatScene or SkySatCollect, of which Sentinel Hub supports SkySatCollect.
productBundle parameter
SkySat data can be ordered through Sentinel Hub either as scaled top of the atmosphere reflectance or surface reflectance, according to the requested asset type.
The value of the productBundle parameter specifies what will be ordered:
itemType value | productBundle value | Ordered Optical Asset Type | Ordered Bands |
|---|---|---|---|
SkySatCollect | analytic_udm2 | top of the atmosphere reflectance | red, blue, green, nir, udm1, clear, snow, shadow, haze_light, haze_heavy, cloud, confidence |
SkySatCollect | analytic_sr_udm2 | surface reflectance | red, blue, green, nir, udm1, clear, snow, shadow, haze_light, haze_heavy, cloud, confidence |
SkySatCollect | panchromatic | top of the atmosphere radiance | pan, udm |
harmonizeTo parameter
Harmonization tool is not available for SkySat data, always use value NONE.
Other parameters
Other parameters are set by SH and cannot be changed by the user.
| Provider's parameter / tool | The values used by SH for ordering |
|---|---|
| Top of Atmosphere Reflectance (toar) tool | is applied for top of atmosphere asset types with toar scale factor 10000 not applied for panchromatic band. |
| Clip tool | is applied |
More information:
- https://developers.planet.com/apis/orders/tools/#tools-reference
- https://developers.planet.com/apis/orders/product-bundles-reference/
Note: If you would need any other SkySat product, please contact us.
Once your order is successfully finished the ordered data will be available in one of your BYOC collections. The tiles in the collection will correspond to SkySat products. To access the data you will need the id of this collection.
Accessing SkySat archive data
Accessing of the SkySat data is similar to accessing any other BYOC data. All processing and filtering options listed there can be used. However, the settings specific for accessing of SkySat data are listed below.
Endpoint Locations
| Service | Notes |
|---|---|
| https://services.sentinel-hub.com/ | Contains the data purchased by individual user |
Filtering Options
collectionId
Use the id of the BYOC collection into which your SkySat data was delivered as a value of parameter input.data.type in the process API requests. See BYOC data access for more information.
Available Bands and Data
This chapter will explain the bands and data which can be set in the evalscript input object.
Any string listed in the column Name can be an element of the input.bands array in your evalscript.
Note that the panchromatic band can only be ordered separately from other bands. It must also be stored in a separate BYOC data collection.
Product bundle analytic_udm2 and analytic_sr_udm2
| Name | Description | Resolution |
|---|---|---|
| blue | Blue, 450 - 515 nm | 0.5 m |
| green | Green, 515 - 595 nm | 0.5 m |
| red | Red, 605 - 695 nm | 0.5 m |
| nir | Near Infrared, 740 - 900 nm | 0.5 m |
| clear | Usable Data mask - Clear mask | 0.5 m |
| snow | Usable Data mask - Snow mask | 0.5 m |
| shadow | Usable Data mask - Shadow mask | 0.5 m |
| haze_light | Usable Data mask - Light haze mask | 0.5 m |
| haze_heavy | Usable Data mask - Heavy haze mask | 0.5 m |
| cloud | Usable Data mask - Cloud mask | 0.5 m |
| confidence | Usable Data mask - Confidence map | 0.5 m |
| udm1 | Unusable Data Mask | 0.5 m |
| dataMask | The mask of data/no data pixels (more). | N/A* |
* dataMask has no source resolution as it is calculated for each output pixel.
Note: Band names were updated in March 2024 for consistency. Previously the band names were: Blue, Green, Red, NIR, UDM2_Clear, UDM2_Snow, UDM2_Shadow, UDM2_LightHaze, UDM2_HeavyHaze, UDM2_Cloud, UDM2_Confidence, UDM. Although evalscripts with the old band names still work, we recommend always use the new band names.
Product bundle panchromatic
| Name | Description | Resolution |
|---|---|---|
| pan | Pan, 450 - 900 nm | 0.5 m |
| udm | Unusable Data Mask | 0.5 m |
| dataMask | The mask of data/no data pixels (more). | N/A* |
* dataMask has no source resolution as it is calculated for each output pixel.
Note: Band names were updated in March 2024 for consistency. Previously the band names were: PAN, UDM. Although evalscripts with the old band names still work, we recommend always use the new band names.
Units
The data values for each band in your custom script are presented in the units as specified here. In case more than one unit is available for a given band, you may optionally set the value of input.units in your evalscript setup function to one of the values in the Sentinel Hub Units column. Doing so will present data in that unit. The Sentinel Hub units parameter combines the physical quantity and corresponding units of measurement values. As such, some names more closely resemble physical quantities, others resemble units of measurement.
The Source Format specifies how and with what precision the digital numbers (DN) from which the unit is derived are encoded. Bands requested in DN units contain the pixel values which are the result of ordering the data as explained in the chapter Ordering SkySat Data. Note that resampling may produce interpolated values. DN is also used whenever a band is derived computationally (like dataMask); such bands can be identified by having DN units and N/A source format.
For SkySat bands, DN are the default and only unit. Reflectance values can be obtained for the Red, Green, Blue and NIR bands using the simple formula: reflectance = DN / 10000. Radiance values can be obtained for PAN band using the simple formula: radiance = DN / 10000.
The Typical Range indicates what values are common for a given band and unit, however outliers can be expected.
| Band | Physical Quantity (units) | Sentinel Hub Units | Source Format | Typical Range |
|---|---|---|---|---|
| red, green, blue, nir | Scaled reflectance (unitless) | DN | UINT16 | 0 - 4000. Highly reflective pixels can have values above 10000. |
| pan | Scaled radiance | DN | UINT16 | 0 - 4000. Highly reflective pixels can have values above 10000. |
| clear | Clear mask (unitless) | DN | UINT8 | 0 - not clear 1 - clear |
| snow | Snow mask (unitless) | DN | UINT8 | 0 - not snow 1 - snow |
| shadow | Shadow mask (unitless) | DN | UINT8 | 0 - not shadow 1 - shadow |
| haze_light | Light haze mask (unitless) | DN | UINT8 | 0 - not light haze 1 - light haze |
| haze_heavy | Heavy haze mask (unitless) | DN | UINT8 | 0 - not heavy haze 1 - heavy haze |
| cloud | Cloud mask (unitless) | DN | UINT8 | 0 - not cloud 1 - cloud |
| confidence | Confidence map (percent) | DN | UINT8 | 0 - 100 |
| udm1/udm | Unusable data mask (unitless) | DN | UINT8 | 0 - fully usable data other - potentially problematic/unusable data Full description is in Planet's documentation (Page 91, Section 2. UNUSABLE DATA MASK FILE). |
| dataMask | N/A | DN | N/A | 0 - no data 1 - data |
Mosaicking
All mosaicking types are supported.
Note: Part of SkySat data delivery are also cover geometries, which get automatically assigned to tiles in Sentinel Hub SkySat data collection. There are instances where the cover geometries contain nodata pixels, often at the edges of tiles. This might result in data gaps when visualizing the data in EO Browser or accessing it with Sentinel Hub APIs. Please review the Workarounds section in BYOC API documentation to learn how you can utilize mosaicking TILE and dataMask band in your evalscript to obtain data values in such cases.