NASA PACE (OCI, SPEXone, HARP2)¶

The pace gatherer queries the NASA Common Metadata Repository (CMR) to search and download observations from the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite mission.

Overview¶

Provider: NASA Goddard Space Flight Center / Ocean Biology DAAC (OB.DAAC)
Official Mission Website: pace.gsfc.nasa.gov
Data Archive (OB.DAAC): oceancolor.gsfc.nasa.gov
Registration: NASA Earthdata Signup
Mission: PACE (launched February 2024)
Instruments:
OCI: Ocean Color Instrument (hyperspectral radiometer, ultraviolet to shortwave infrared, 340–2260 nm)
SPEXone: Spectro-polarimeter measuring linear polarization in the 385–770 nm range
HARP2: Hyper-Angular Rainbow Polarimeter measuring wide-angle multi-spectral polarization
Authentication: NASA Earthdata Login
Output Format: NetCDF-4 binary files

Supported Instruments & Products¶

Instrument	Product Type	Processing Level	Description
OCI	`L1C`	Level-1C	Hyperspectral top-of-atmosphere radiances mapped to standard grid
OCI	`L1B`	Level-1B	Calibrated at-aperture radiances
OCI	`L2_AOP`	Level-2	Aerosol optical properties and ocean color products
OCI	`L2_BGC`	Level-2	Ocean biogeochemistry and chlorophyll-a concentrations
OCI	`L3M`	Level-3	Level-3 binned global/regional mapped products
SPEXone	`L1C`	Level-1C	Polarimetric aerosol and cloud science granules
SPEXone	`L1B`	Level-1B	Calibrated polarimetric radiances
SPEXone	`L2_AOP`	Level-2	Retrieved aerosol microphysical properties
HARP2	`L1C`	Level-1C	Hyper-angular polarimetric science granules
HARP2	`L1B`	Level-1B	Multi-angle calibrated radiances

Parameters Reference¶

Parameter	Type	Default	Description
`instrument`	`str`	required	Instrument identifier (`"OCI"`, `"SPEXone"`, or `"HARP2"`)
`product_type`	`str`	`"L1C"`	Product type / level (`"L1C"`, `"L1B"`, `"L2_AOP"`, etc.)
`start_time`	`str`	required	Start datetime in ISO 8601 UTC (e.g. `"2024-06-01T10:00:00Z"`)
`end_time`	`str`	required	End datetime in ISO 8601 UTC (e.g. `"2024-06-01T14:00:00Z"`)
`grid`	`Grid \\| dict \\| None`	`None`	Spatial Region of Interest (ROI) with center coordinates or `site`
`bounding_box`	`list[float] \\| None`	`None`	`[min_lon, min_lat, max_lon, max_lat]`
`limit`	`int \\| None`	`None`	Maximum number of granules to fetch
`max_workers`	`int`	`1`	Number of concurrent worker threads for downloading multiple granules
`short_name`	`str \\| None`	`None`	Optional direct CMR collection short name override

Authentication Setup¶

Create a free account on the NASA Earthdata Registration Page.

# Save to credentials.yaml (shared by PACE and MODIS)
gathering auth login earthdata -u "your_earthdata_username" -p "your_earthdata_password"

# Or set in environment
export EARTHDATA_USERNAME="your_earthdata_username"
export EARTHDATA_PASSWORD="your_earthdata_password"

Python API Usage¶

from gathering import Task

# Task 1: PACE OCI Hyperspectral L1C over Southern Spain
task_oci = Task.pace(
    instrument="OCI",
    product_type="L1C",
    start_time="2024-06-01T10:00:00Z",
    end_time="2024-06-01T14:00:00Z",
    grid={"site": "Granada", "size_yx": [100, 100], "resolution_m": 1000.0},
    limit=2,
)

# Task 2: PACE SPEXone Polarimetric L1C
task_spexone = Task.pace(
    instrument="SPEXone",
    product_type="L1C",
    start_time="2024-09-01T00:00:00Z",
    end_time="2024-09-01T12:00:00Z",
    grid={"site": "El_Arenosillo", "size_yx": [50, 50], "resolution_m": 2500.0},
    limit=2,
)

# Task 3: PACE HARP2 Rainbow Polarimeter
task_harp2 = Task.pace(
    instrument="HARP2",
    product_type="L1C",
    start_time="2025-01-01T00:00:00Z",
    end_time="2025-01-01T06:00:00Z",
    bounding_box=[-10.0, 35.0, 5.0, 45.0],
    limit=2,
)

CLI Usage¶

gathering pace \
  --instrument OCI \
  --product_type L1C \
  --start_time 2024-06-01T10:00:00Z \
  --end_time 2024-06-01T14:00:00Z

YAML Configuration¶

PACE OCI L1CPACE SPEXone L1CPACE HARP2 L1C

# ==============================================================================
# NASA PACE — OCI Hyperspectral Top-of-Atmosphere (Level-1C)
# ==============================================================================

source: pace

instrument: OCI
product_type: L1C

start_time: "2024-06-01T10:00:00Z"
end_time: "2024-06-01T14:00:00Z"

grid:
  center_lat_lon: [36.5, -4.5]        # Malaga / Mediterranean Coast
  size_yx: [100, 100]
  resolution_m: 1000.0
  projection: "latlon"

limit: 2
only_granules_list: false
return_s3_paths: false
overwrite_cache: false

# ==============================================================================
# NASA PACE — SPEXone Polarimetric Science Granules
# ==============================================================================

source: pace

instrument: SPEXone
product_type: L1C

start_time: "2024-09-01T00:00:00Z"
end_time: "2024-09-01T12:00:00Z"

grid:
  site: "El_Arenosillo"
  size_yx: [50, 50]
  resolution_m: 2500.0
  projection: "latlon"

limit: 2
overwrite_cache: false

# ==============================================================================
# NASA PACE — HARP2 Hyper-Angular Rainbow Polarimeter L1C
# ==============================================================================

source: pace

instrument: HARP2
product_type: L1C

start_time: "2025-01-01T00:00:00Z"
end_time: "2025-01-01T06:00:00Z"

grid:
  site: "Granada"
  size_yx: [100, 100]
  resolution_m: 5000.0
  projection: "latlon"

limit: 2
overwrite_cache: false

Download Directory Structure¶

/workspace/.cache/gathering/pace/
└── OCI/
    └── L1C/
        └── 2024/
            └── 06/
                └── 01/
                    └── PACE_OCI.20240601T120000.L1C.5KM.nc