POES Satellite Data Guide

Polar Operational Environmental Satellites (POES) provide continuous high-latitude measurements of energetic particles, magnetic fields, and spacecraft position. This guide explains the unified POES endpoint, available satellites, and data fields.

Overview

Satellite Network: NOAA POES satellites operate in sun-synchronous polar orbits at approximately 840 km altitude, passing over the Earth's poles about 14 times per day. These satellites monitor energetic particles and magnetic fields in the auroral regions.

Data Coverage: 1998-present
Update Interval: 1-minute granularity; data typically available within 1-3 days after downlink
Total Records: >18 million measurements across 5 satellites

Active Satellites

Satellite	Status	Orbit Type	Agency
NOAA-15	Operational	Sun-synchronous (~840 km)	NOAA
NOAA-18	Operational	Sun-synchronous (~840 km)	NOAA
NOAA-19	Operational	Sun-synchronous (~840 km)	NOAA
MetOp-01 (MetOp-A)	Operational	Sun-synchronous (~840 km)	EUMETSAT
MetOp-03 (MetOp-B)	Operational	Sun-synchronous (~840 km)	EUMETSAT

Data Fields

The unified POES endpoint returns comprehensive measurements organized into four categories:

1. Position Data (Geodetic Coordinates)

• latitude - Satellite latitude in degrees (-90 to +90)
• longitude - Satellite longitude in degrees (-180 to +180)
• altitude_km - Satellite altitude above sea level (kilometers)

2. Magnetic Field Data (IGRF Model)

Measurements of Earth's magnetic field in two reference frames:

At Satellite Location

• btot_sat - Total magnetic field magnitude (nanoTesla)
• bp_sat - Parallel (B_||) component (nanoTesla)
• br_sat - Radial (B_r) component (nanoTesla)
• bt_sat - Theta (B_θ) component (nanoTesla)

At Foot of Field Line (Earth's Surface)

• btot_foot - Total field at footpoint (nanoTesla)
• bp_foot - Parallel component at footpoint (nanoTesla)
• br_foot - Radial component at footpoint (nanoTesla)
• bt_foot - Theta component at footpoint (nanoTesla)

Cartesian Coordinates (Satellite Frame)

• bx_sat - X component (nanoTesla)
• by_sat - Y component (nanoTesla)
• bz_sat - Z component (nanoTesla)

3. Electron Flux Data (4 Energy Channels)

Energetic electron measurements across different energy levels:

• elec_flux_e0 - Electron flux in E0 channel (particles/cm²/s/sr)
• elec_flux_e1 - Electron flux in E1 channel (particles/cm²/s/sr)
• elec_flux_e2 - Electron flux in E2 channel (particles/cm²/s/sr)
• elec_flux_e3 - Electron flux in E3 channel (particles/cm²/s/sr)
• elec_energy - Reference energy array for electron channels (keV) [E0, E1, E2, E3]

4. Proton Flux Data (8 Energy Channels)

Energetic proton measurements across multiple energy levels:

• prot_flux_p1 through prot_flux_p8 - Proton flux in P1-P8 channels (particles/cm²/s/sr)
• prot_energy - Reference energy array for proton channels (MeV) [P1, P2, ..., P8]

5. Alpha Particle Flux Data (4 Energy Channels)

Energetic alpha particle (He²⁺) measurements:

• alpha_flux_a1 through alpha_flux_a4 - Alpha flux in A1-A4 channels (particles/cm²/s/sr)
• alpha_energy - Reference energy array for alpha channels (MeV) [A1, A2, A3, A4]

6. Metadata

• timestamp - Measurement time (ISO 8601 UTC)
• satellite - Satellite identifier (NOAA15, NOAA18, NOAA19, METOP01, METOP03)

API Usage

Get POES data for a date range

Code
 
curl -X GET "https://api.mission.space/api/v1/poes\
  ?start_time=2025-01-01T00:00:00Z\
  &end_time=2025-01-02T00:00:00Z\
  &limit=1000" \
  -H "X-API-Key: your_api_key"

Filter by satellite

Code
 
curl -X GET "https://api.mission.space/api/v1/poes\
  ?start_time=2025-01-01T00:00:00Z\
  &end_time=2025-01-02T00:00:00Z\
  &satellite=NOAA19\
  &limit=500" \
  -H "X-API-Key: your_api_key"

Paginate through results

Code
 
# First page
curl -X GET "https://api.mission.space/api/v1/poes\
  ?start_time=2025-01-01T00:00:00Z\
  &end_time=2025-01-31T23:59:59Z\
  &limit=10000\
  &offset=0" \
  -H "X-API-Key: your_api_key"

# Second page
curl -X GET "https://api.mission.space/api/v1/poes\
  ?start_time=2025-01-01T00:00:00Z\
  &end_time=2025-01-31T23:59:59Z\
  &limit=10000\
  &offset=10000" \
  -H "X-API-Key: your_api_key"

Response Example

Code
 
{
  "status": "success",
  "data": [
    {
      "timestamp": "2025-01-01T12:34:56Z",
      "satellite": "NOAA19",
      "latitude": 45.3,
      "longitude": 125.8,
      "altitude_km": 830.0,
      "btot_sat": 45230.5,
      "bp_sat": 22100.3,
      "br_sat": 19340.2,
      "bt_sat": 18500.1,
      "bx_sat": 35100.2,
      "by_sat": 22500.1,
      "bz_sat": 18200.3,
      "elec_flux_e0": 245.5,
      "elec_flux_e1": 3400.2,
      "elec_flux_e2": 1250.8,
      "elec_flux_e3": 425.3,
      "prot_flux_p1": 125.5,
      "prot_flux_p2": 234.2,
      "prot_flux_p3": 456.1,
      "prot_flux_p4": 389.7,
      "prot_flux_p5": 1250.5,
      "prot_flux_p6": 2340.1,
      "prot_flux_p7": 3450.2,
      "prot_flux_p8": 4560.8,
      "alpha_flux_a1": 25.5,
      "alpha_flux_a2": 125.1,
      "alpha_flux_a3": 245.3,
      "alpha_flux_a4": 450.2,
      "elec_energy": [30.0, 100.0, 300.0, 800.0],
      "prot_energy": [0.8, 2.2, 3.3, 5.5, 10.0, 30.0, 60.0, 100.0],
      "alpha_energy": [2.0, 5.0, 10.0, 40.0]
    }
  ],
  "meta": {
    "total": 18432,
    "returned": 1,
    "limit": 1000,
    "offset": 0
  }
}

Common Use Cases

Monitoring Auroral Electron Precipitation

Query elec_flux_* fields during geomagnetic substorms to track electron precipitation at high latitudes.

Radiation Belt Studies

Track prot_flux_* and alpha_flux_* data to study radiation belt dynamics and particle acceleration.

Magnetic Field Analysis

Use btot_sat and component fields (bp_sat, br_sat, bt_sat) for magnetospheric studies and field-aligned current analysis.

Space Weather Alerts

Sudden increases in prot_flux_* can indicate solar energetic particle events. Monitor during solar activity.

Data Quality Notes

• Gaps may occur during satellite maintenance or data transmission issues
• Fields with null values indicate missing or excluded data for that measurement
• All flux values are in particles/(cm² · s · sr) unless otherwise noted
• Energy values represent the geometric center of each channel's response function
• Timestamps are in UTC; convert to local time as needed for your analysis

API Parameters

Parameter	Type	Required	Description	Example
start_time	ISO 8601	Yes	Start of time range	2025-01-01T00:00:00Z
end_time	ISO 8601	Yes	End of time range	2025-01-02T00:00:00Z
satellite	String	No	Filter by satellite	NOAA19
limit	Integer	No	Records per page (default 1000, max 10000)	5000
offset	Integer	No	Pagination offset	0

See Also

• API Reference: /poes - Full endpoint documentation
• Geomagnetic Storms - Related space weather phenomena
• GOES Data - Complementary geostationary satellite measurements