2.9 Auxiliary Files

2.9.1 Summary of Auxiliary Datasets

2.9.1.1 MERIS Instrument Data File

This data file contains all the parameters needed for processing MERIS data in any band configurations. Therefore, it also contains the data needed for geolocation and resampling.

FILE ID: MER_INS_AX
TYPE: Auxiliary
USE: Level 1b processing
UPDATED: Infrequently
SIZE: MPH(1,247 bytes) + SPH(2,898 bytes) + DSs (approx. 2.936 MBytes) =2,940,344 Bytes

2.9.1.2 MERIS Level 1b Control Parameters Data File

This file contains processing parameters used during the generation of the Level 1b products.

FILE ID: MER_CP1_AX
TYPE: Auxiliary
USE: Level 1b processing
UPDATED: Infrequently
SIZE: MPH(1,247 bytes) + SPH(5,138 bytes) + DSs(12,872 bytes) = 19,257 bytes

2.9.1.3 Radiometric Calibration Data File

FILE ID: MER_RAC_AX
TYPE: Auxiliary
USE: Level 1b processing
UPDATED: Nominally every 2 weeks
SIZE: MPH(1,247 bytes) + SPH(2,338 bytes) + DSs(2,166,097 bytes) = 2,169,682 bytes

2.9.1.4 Digital Roughness Model Data File

FILE ID: MER_DRM_AX
TYPE: Auxiliary
USE: Level 1b processing
UPDATED: Infrequently
SIZE: MPH(1,247 bytes) + SPH(658 bytes) + DSs(approx. 37 MB) = approx. 37.3 MB

2.9.1.5 Coastline/Land/Ocean Data File

The Land/Sea Mask file classifies points on the Earth's surface as Land/Sea or Coastline.

FILE ID: AUX_LSM_AX
TYPE: Auxiliary
USE: Level 1b processing
UPDATED: Infrequently.
SIZE: MPH(1,247 bytes) + SPH(1,778 bytes) + GADS(approx. 12.3 MB) = approx. 13 MB

2.9.1.6 Aerosol Climatology Data File

FILE ID: MER_AER_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Infrequently
SIZE: MPH(1,247 bytes) + SPH(1,498 bytes) + GADSs (1,233,444 bytes) = 1,236,189 bytes

2.9.1.7 Level 2 Control Parameters Data File

FILE ID: MER_CP2_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Infrequently
SIZE: MPH(1,247 bytes) + SPH(1,498 bytes) + DSs(13,083 bytes) = 15,828 bytes

2.9.1.8 Atmosphere Parameters Data File

FILE ID: MER_ATP_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Once a year
SIZE: MPH(1,247 bytes) + SPH(2,898 bytes) + DSs(1,133,289) = 1,137,434 bytes

2.9.1.9 Water Vapour Parameters Data File

FILE ID: MER_WVP_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Once a year
SIZE: MPH(1,247 bytes) + SPH(1,778 bytes) + GADSs(33,437,320 Bytes) = 33,440,345 Bytes

2.9.1.10 Ocean Aerosols Parameters Data File

FILE ID: MER_OAP_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Once a year
SIZE: MPH(1,247 bytes) + SPH(2,338 bytes) + DSs(47,535,994 bytes) = 47,539,579 bytes

2.9.1.11 Land Aerosols Parameters Data File

FILE ID: MER_LAP_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Once a year
SIZE: MPH(1,247 bytes) + SPH(4,018 bytes) + DSs(2,203,548 bytes) = 2,207,813 bytes

2.9.1.12 Ocean I Parameters Data File

FILE ID: MER_OC1_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Once a year
SIZE: MPH(1,247 bytes) + SPH(1,778 bytes) + DSs(2,634,189 bytes) = 2,637,214 bytes.

2.9.1.13 Ocean II Parameters Data File

FILE ID: MER_OC2_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Once a year
SIZE: MPH(1,247 bytes) + SPH(1,778 bytes) + DSs(19,727,376) = 19,730,401 bytes

2.9.1.14 Cloud Measurement Parameters Data File

FILE ID: MER_CMP_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Once a year
SIZE: MPH(1,247 bytes) + SPH(2,058 bytes) + DSs(5,415,011 bytes) = 5,418,316 bytes

2.9.1.15 Land Vegetation Index Parameters Data File

FILE ID: MER_LVI_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Once a year
SIZE: MPH(1,247 bytes) + SPH(378 bytes) + GADS(209 bytes) = 1,834 bytes

2.9.1.16 Surface Confidence Map File

The Surface Confidence Map file provides a Boolean flag which indicates for any location on Earth, whether the land/water classification provided by the Land/Sea Mask file is fully asserted or not.

FILE ID: MER_SCM_AX
TYPE: Auxiliary
USE: Level 2 processing
UPDATED: Infrequently.
SIZE: MPH(1,247 bytes) + SPH(938 bytes) + GADS(7,608,256 bytes) = 7,610,441 bytes

2.9.1.17 ENVISAT Orbit Data Files

The instrument ground processing software uses the CFI orbit propagator software module and an orbit state vector as input to calculate the satellite position all along the orbit. The following describes the product structure of the FOS predicted and restituted orbit state vector files.

FILE_ID: FOS Predicted: AUX_FPO_AX
FOS Restituted: AUX_FRO_AX
USE: Used during ground processing
UPDATED: Once per day
SIZE:
AUX_FPO_AX: One MDSR per orbit, file covers 6 days (86 MDSRs). Size = 1,247 (MPH) + 378 (SPH) + 129 * 86 MDSRs = 12,719 bytes.
AUX_FRO_AX: One MDSR per minute, file covers 1 day, with 60 minute overlap (1,500 MDSRs). Size = 1,247 (MPH) + 378 (SPH) + 129 * 1,500 = 195,125 bytes.

2.9.1.18 ECMWF Data Files

ECMWF data files contain meteorological information. They are ingested into the Payload Data Segment (PDS) ground segment on a regular basis and are used by various instrument processors during the generation of products.

There are two kinds of ECMWF data: Forecast data and analysis data. Forecast data is used in NRT processing, while analysis data is used during OFL product generation. Both forecast data and analysis data files have the same format.

FILE ID: AUX_ECF_AX - ECMWF Forecast data
AUX_ECA_AX - ECMWF Analysis data
TYPE: Auxiliary
USE: Level 1b processing, Level 2 processing
UPDATED: ECMWF files enter the PDS every 6 hours. There are 4 analysis files and 4 forecast files, each valid for a 12 hour time period.
SIZE: MPH(1,247 bytes) + SPH(378 bytes) + DSs(approx. 8.7 MB) = approx. 8.7 MB

2.9.1.19 Digital Elevation Model

This file contains a world Digital Elevation Model (DEM). The GADS of this file contains the elevation values on a regular grid. The coverage of the grid is from 180+1/24 W to 180 - 1/24 E degrees in longitude and from -90 + 1/24 to 90 -1/24 degrees in latitude. The resolution of the grid is 1/12 degree in longitude and 1/12 degree in latitude. One value is recorded at each grid point.

FILE ID: AUX_DEM_AX
TYPE: Auxiliary
USE: Level 1b processing
UPDATED: Infrequently
SIZE: MPH(1,247 bytes) + SPH(658 bytes) + DSs(37,325,059 bytes) = approx. 38 MB