Level-2 product definition

Level-2 product definition#

The following is an initial proposal for a CIMR L2 soil moisture product structure. Two L2 products are envisioned: One based on L-band TBs at their native resolution and one based on L-band TBs sharpened with C-/X-band TBs for an enhanced resolution.

The main content of the L2 files are the gridded soil moisture and vegetation optical depth fields. Scene and status flags provide information about the quality and status of the retrieval, respectively. For this prototype implementation, the gridded brightness temperature fields and the RMSE between measured and modelled brightness temperatures are provided as additional output.

Table 1 Level-2 Soil Moisture product (36 km grid)#

Parameter

Description

Units

Dimensions*

time

Time of observation

seconds

(964, 406)

EASE row index

Row index in EASE2 grid

-

(964, 406)

EASE column index

Column index in EASE2 grid

-

(964, 406)

lon

Longitude [0\(^{\circ}\), 360\(^{\circ}\)]

deg East

(964, 406)

lat

Latitude [90\(^{\circ}\)S, 90\(^{\circ}\)N]

deg North

(964, 406)

SM

Soil Moisture

m\(^{3}\)/m\(^{3}\)

(964, 406)

VOD

Vegetation Optical Depth

-

(964, 406)

scene_flags

Flag to indicate difficult inversion situations

8-bit flag

(964, 406)

status_flag

Retrieval status flag

n/a

(964, 406)

TBV_L

Gridded L-band TBV

K

(964, 406)

TBH_L

Gridded L-band TBH

K

(964, 406)

TB_L_RMSE

RMSE between measured and modeled TB

K

(964, 406)

Table 2 Level-2 enhanced Soil Moisture product (9 km grid)#

Parameter

Description

Units

Dimensions*

time

Time of observation

seconds

(3856, 1624)

EASE row index

Row index in EASE2 grid

-

(3856, 1624)

EASE column index

Column index in EASE2 grid

-

(3856, 1624)

lon

Longitude [0\(^{\circ}\), 360\(^{\circ}\)]

deg East

(3856, 1624)

lat

Latitude [90\(^{\circ}\)S, 90\(^{\circ}\)N]

deg North

(3856, 1624)

SM_E

Soil Moisture (enhanced resolution)

m\(^{3}\)/m\(^{3}\)

(3856, 1624)

VOD_E

Vegetation Optical Depth (enhanced resolution)

-

(3856, 1624)

scene_flags

Flag to indicate difficult inversion situations

8-bit flag

(3856, 1624)

status_flag

Retrieval status flag

n/a

(3856, 1624)

TBV_L_E

Gridded L-band TBV (enhanced resolution)

K

(3856, 1624)

TBH_L_E

Gridded L-band TBH (enhanced resolution)

K

(3856, 1624)

TB_L_E_RMSE

RMSE between measured and modeled TB
(enhanced resolution)

K

(3856, 1624)

* Dimensions are equivalent to the global EASE2 grids at 36 km and 9 km resolution, respectively.
The final grid resolution will be decided based on further tests on the tradeoff between noise and spatial resolution.