D-HSSM - Home

Product overview¶

D-HSSM further enhances spatial resolution to 100 m (0.0009° grid spacing) using the same Sentinel-1 SAR downscaling methodology as D-ESSM. This product is available for custom regions only and uses the same variable and flag structure as D-ESSM.

Figure 1:D-HSSM high-resolution surface soil moisture over Mexico, 30 August 2025. Values in m³/m³.

Property	Value
Spatial resolution	100 m (0.0009° grid spacing)
Data level	L5
Temporal coverage	May 2015–present
Unit	m³/m³
Coverage	Custom regions only

Variants:

d-hssm — Standard product with ~4-day latency
d-hssm-nrt — Near-real-time product with ~1-day latency

NetCDF4 format¶

Global attributes¶

Attribute	Description
`description`	Daily High-resolution Surface Soil Moisture
`creator`	SPIRE GLOBAL
`processing_center`	Spire EILAND
`file_created_time_utc`	UTC creation timestamp
`data_level`	L5
`source`	D-MSSM vMA.mi and Sentinel-1 downscaling parameters vMA.mi
`input_data_version`	Input data release version (e.g. v02.01.98)
`release_tag`	Data release version (e.g. v04.00.98)
`code_version`	Production code version (may not be present in all files)
`git_hash`	Production code commit hash (may not be present in all files)
`grid_mapping`	spatial_ref
`feed`	Data tier: `"standard"` or `"nrt"`

Variables¶

Variable	Description	Dims	Type	Fill value	Scale factor	Unit
`d_hssm`	Daily High-resolution Surface Soil Moisture downscaled from D-MSSM	(y, x)	uint8	255	0.005	m³/m³
`eflag`	Enhanced flag — 0 = Enhanced, 1 = Not enhanced	(y, x)	uint8	255	—	—
`qflag`	Quality flag — 8-bit flags (same definitions as D-ESSM)	(y, x)	uint8	255	—	—
`aflag`	Advisory flag — 0 = recommended, 1 = not recommended	(y, x)	uint8	255	—	—
`y`	Latitude coordinate	(y)	float64	NaN	—	degrees_north
`x`	Longitude coordinate	(x)	float64	NaN	—	degrees_east
`spatial_ref`	Coordinate reference system (WGS 84, EPSG:4326)	()	int64	—	—	—

The eflag and qflag use the same definitions as D-ESSM.

CSV and GeoJSON format¶

Same structure as D-ESSM CSV/GeoJSON, with d_hssm replacing d_essm.

JSON (point API) response¶

{
  "data": [
    {
      "location": {
        "coordinates": {
          "lat": 14.0,
          "lon": 100.5
        }
      },
      "times": {
        "valid_time": "2026-02-10 12:00:00"
      },
      "values": {
        "d_hssm": 0.335,
        "eflag": 0.0,
        "qflag": 0.0,
        "lat": 14.0,
        "lon": 100.5,
        "aflag": 0,
        "feed": "standard"
      }
    }
  ],
  "meta": {
    "message": null
  }
}