SMOS Level-2C Datacube Service
The service provides
ESA SMOS
Level-2 data in form of analysis-ready Level-2C datacubes with the
dimensions
time,
lat, and
lon. The datacubes are computed on-the-fly
from the SMOS data archive
s3://EODATA/SMOS hosted on
CREODIAS.
Spatial coverage and resolution
The SMOS data is provided globally or for a custom area of interest
using a geographic projection (
EPSG:4326 aka WGS84,
World Geodetic System 1984). Users can choose from five spatial resolutions by specifying a resolution
level ranging from zero to four. Zero refers to a resolution of
360/8192 ~ 0.044 degrees ~ 4.88 km. Higher levels subsequently increase the
resolution by a factor of two.Note that the native spatial resolution of SMOS data is roughly 25 km.
This service performs an oversampling of the data to ensure no information
is lost during spatial projection. It therefore uses a nearest-neighbor
resampling at higher resolution involving pixel duplication.
Temporal coverage and resolution
The SMOS satellite completes one orbit approximately every 100.1 minutes.
Therefore, 29 (number of orbits times two) level-2 data products are stored per
day. If no aggregation interval is specified, the service will append a time
step for each level-2 data product to the datacube. Otherwise, data variables
are aggregated by their mean, with a minimum aggregation interval of one day.Currently, the provided time range must not exceed 400 days.
Service parameters
| Name |
Type |
Value range |
| product_type |
string |
"SMOS-L2C-SM" or "SMOS-L2C-OS" |
| time_range |
string |
"YYYY-MM-DD/YYYY-MM-DD" |
| agg_interval |
string |
"none", "1D", "2D", "4D", defaults to "1D" |
| bbox |
string |
Spatial AOI as Geometry WKT, defaults global coverage |
| res_level |
integer |
0 to 4, defaults to 0 |
Service output
The output of the service is a SMOS Level-2C raster datacube comprising
a number of geophysical data variables with the dimensions
time,
lat,
and
lon. The variables depend on the selected SMOS product type, either
Soil Moisture or Ocean Salinity. The datacube is provided as a
Zarr v2 dataset (
.zarr).Soil Moisture datacubes of type
SMOS-L2C-SM contain the following variables:
| Variable |
Type |
Units |
| Soil_Moisture |
float32 |
m3 m-3 |
| Soil_Moisture_DQX |
float32 |
m3 m-3 |
| Chi_2 |
uint8 |
- |
| Chi_2_P |
uint8 |
- |
| N_RFI_Y |
uint16 |
- |
| N_RFI_X |
uint16 |
- |
| RFI_Prob |
uint8 |
- |
Ocean Salinity datacubes of type
SMOS-L2C-OC contain the following variables:
| Variable |
Type |
Units |
| SSS_anom |
float32 |
psu |
| SSS_corr |
float32 |
psu |
| Sigma_SSS_anom |
float32 |
psu |
| Sigma_SSS_corr |
float32 |
psu |
| Dg_quality_SSS_anom |
uint16 |
- |
| Dg_quality_SSS_corr |
uint16 |
- |
| Dg_chi2_corr |
uint16 |
- |
| Dg_RFI_X |
uint16 |
- |
| Dg_RFI_Y |
uint16 |
- |
| Coast_distance |
uint8 |
- |
| Mean_acq_time |
float32 |
dd |
| X_swath |
float32 |
m |
Supported delivery methods
- AWS S3 bucket
- EOxHub Managed Object Storage
- One-time Download
Pricing
The price depends on the selected time range and area of interest.
The minimum price per request is 10€; a non-linearly increasing discount
is provided for larger coverages:
| Time range |
Spatial AOI |
Price |
| 1 day |
10° x 10° |
10€ |
| 1 day |
90° x 90° |
10€ |
| 1 month |
90° x 90° |
25€ |
| 1 month |
global |
140€ |
| 1 year |
90° x 90° |
150€ |
| 1 year |
global |
1150€ |