{
  "termsOfUse": "https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf",
  "keywordVersion": "draft",
  "schemeVersion": "2025-07-25",
  "viewer": "https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/projects/dfcd21aa-d627-4c52-845f-fd5a33f370e9",
  "lastModifiedDate": "2026-08-10T19:18:43.522Z",
  "uuid": "dfcd21aa-d627-4c52-845f-fd5a33f370e9",
  "prefLabel": "CPF",
  "isLeaf": true,
  "scheme": {
    "shortName": "projects",
    "longName": "Projects"
  },
  "broader": [
    {
      "uuid": "0c89f3f4-7ab1-43ce-89ee-795d35f0e30a",
      "prefLabel": "A - C",
      "scheme": {
        "shortName": "projects",
        "longName": "Projects"
      }
    }
  ],
  "narrower": [],
  "related": [],
  "definitions": [
    {
      "text": "The CLARREO (Calibration Absolute Radiance and Refractivity Observatory) Pathfinder (CPF) mission officially began in 2016 with the directive to achieve two primary mission goals: 1) measure Earth-reflected sunlight with an uncertainty better than 0.6% (k=1) – a 5-10x improvement over existing reflected solar (RS) sensors and 2) serve as an on-orbit intercalibration reference to other orbiting sensors. The high accuracy spectrally-resolved measurements CPF will take are critical to identify the physical drivers of variability of the Earth system. CPF’s unprecedented accuracy, traceable to international standards, and its high spatial and spectral resolution also ideally position CPF to serve as an on-orbit intercalibration reference to other RS instruments. This is essential because most RS instruments experience on-orbit degradation with extended exposure to the extreme space environment. Alternatively, CPF has been designed to be resilient to such on-orbit degradation with its approach to on-orbit calibration. The CPF instrument is a RS spectrometer called HySICS (HyperSpectral Imager for Calibration Science) developed by the Laboratory for Atmospheric and Space Physics (LASP). The CPF payload will be hosted on the International Space Station (ISS) and is planned to take measurements for at least one year.",
      "reference": "https://science.nasa.gov/mission/clarreo-pathfinder/"
    }
  ],
  "altLabels": [
    {
      "category": "primary",
      "text": "CLARREO Pathfinder"
    }
  ],
  "resources": []
}