VIIRS NOAA Land Data Production


Data from Suomi NPP are being used by NOAA to generate, among other things, a suite of Land products for use in a number of applications, ranging from real-time weather operations to forecast model input and environmental monitoring applications.

Most VIIRS land products are currently being processed in NOAA's Interface Data Processing Segment (IDPS), which receives raw instrument data and telemetry from ground stations supporting the Suomi NPP mission. The IDPS converts the Level 0 Raw Data Records (RDRs), generated by sensors on Suomi NPP, into calibrated geolocated Level 1 measurements called Sensor Data Records (SDRs), and then into Level 2+ geophysical parameters or Environmental Data Records (EDRs). In addition to SDRs and EDRs, the IDPS produces Intermediate Products (IPs), which are produced as an interim step in the EDR processing. SDRs, EDRs, and most IPs are stored for long term archiving and distribution at the NOAA Comprehensive Large Array-Data Stewardship System (CLASS). Note that the standard VIIRS IDPS-generated products (EDRs and IPs) are produced in swath-based format. Thus, only information from a single orbit is used, and available 'per-pixel' information from overlapping swaths is not used.

In addition to IDPS, some NOAA Land Products are generated within the Suomi NPP Data Exploitation (NDE) System (products generated by NDE are also referred to as NOAA Unique Products). The NDE Green Vegetation Fraction product is operational and generates a sliding weekly composite, gridded both globally and regionally, on a daily basis. The NDE system will also be running the continuation of the heritage Vegetation Health product suite using VIIRS data as input. The VIIRS Active Fire algorithm that is compliant with the NOAA JPSS Level 1 requirements is being implemented into NDE.

Below is a table of JPSS accuracy requirements (Threshold and Objective accuracy requirements are as listed in version 2.10 of the JPSS Level 1 Requirements Supplement) and estimated performance are based on NOAA and NASA VIIRS Science Team evaluations. Note that additional specifications (that are not listed here) typically apply to each product, such as revisit time, coverage, long term stability and mapping, precision, and uncertainty. Further, each product has an associated set of exclusion conditions (e.g., high solar zenith angles) for which the specifications are relaxed.

table of specs for VIIRS

N/S=No value specified.
PCT=Probability of correct typing.
∞  Results are based on IDPS MX6.2 build, after a look-up table update was implemented.
«   Note performance is dependent on both the spectral band and magnitude of the reflectance (e.g., increased surface brightness results in a      multiplicative error of 5%).
×   Fire Radiative Power (FRP) measurement range threshold requirement. The high end of the FRP Measurement Range threshold requirement      (5000 MW) is based on current design capabilities (i.e., the present 634 K saturation specification for the VIIRS M13 Band) and the      recommendation of the NOAA-NASA Land Science Team. Quantitative assessment of ARP product is pending on availability of quality      reference data, primarily from airborne measurements.
Δ   With EVI gain adjusted to 2.5.
*    17 class IGBP classification.
^    Applies only to Snow/no-snow classification.
#   Ice/ice-free classification
## Ice free, new/young Ice, all other ice.
  VIIRS produces a sea ice concentration IP in clear sky conditions, which is provided as an input to the Ice Surface Temperature calculation.
 °   Uncertainty requirement for Ice Surface Temperature.