University of Colorado at Boulder University of Colorado CU Home Search A to Z Index Map

Quick Facts: Total and Spectral Solar Irradiance Sensor (TSIS)

The JPSS satellite in orbit

The Joint Polar Satellite System (JPSS) is a satellite system used to monitor global environmental conditions, and collect and disseminate data related to weather, atmosphere, oceans, land, and near-space environment. (Courtesy NASA)

Mission Introduction

The Joint Polar Satellite System (JPSS) is the next generation of low Earth orbiting environmental satellites. It is procured by the National Oceanic and Atmospheric Administration (NOAA) through the National Aeronautics and Space Administration (NASA). The JPSS will provide global coverage, monitoring environmental conditions, collecting, disseminating and processing data about the Earth’s weather, atmosphere, oceans, land, near-space environment, and solar irradiance. JPSS will also monitor rescue beacons to help save lives through the international SARSAT program.

The JPSS will be able to monitor the entire planet and provide data for long-range weather and climate forecasts. The data gathered by the JPSS will aid in reducing the potential loss of human life and property by allowing more efficient disaster planning and response to severe weather conditions such as tornadoes and floods.

Citizens will benefit from the satellites’ data in the areas of general aviation, agriculture, emergency response (first responders), and maritime activities. Military users will benefit from the JPSS as well, tactically and strategically. The JPSS will permit the military to capitalize on favorable weather conditions or avoid harsh weather conditions that could hinder maneuverability.

The JPSS will collect a massive amount of very precise Earth surface, atmospheric, solar and space data for 30 different Environmental Data Records using a variety of on-board sensors. This volume of data will allow scientists and forecasters to monitor and predict weather patterns with greater speed and accuracy. JPSS will provide operational continuity of satellite-based observations and products for NOAA Polar-orbiting Operational Environmental Satellites (POES) and the NPOESS Preparatory Project (NPP) mission.

The Total Irradiance Monitor

TIM measures the total light coming from the Sun at all wavelengths. (Courtesy LASP)

LASP Roles

LASP provides:

  • The Total Irradiance Monitor (TIM) instrument
  • The Spectral Irradiance Monitor (SIM) instrument
  • TSIS Principal Investigator, Peter Pilewskie
  • Mission operations for TSIS

LASP Instruments

The Total and Spectral Solar Irradiance Sensor (TSIS) is a dual-instrument package that will acquire solar irradiance during the current decade as part of JPSS. Originally de-manifested during the 2006 National Polar-orbiting Operational Environmental Satellite System (NPOESS) restructuring, TSIS was restored following a decision by the NPOESS Executive Committee because of its critical role in determining the natural forcings of the climate system and the high priority given it by the 2007 Earth Science Decadal Survey. Further restructuring of NPOESS, with climate sensors transitioning to JPSS, will insure the continuity of the solar irradiance Climate Data Record (CDR) through TSIS.

The Spectral Irradiance Monitor (SIM) instrument

SIM will measure how the light from the Sun is distributed by wavelength. (Courtesy LASP)

TSIS is comprised of the Total Irradiance Monitor, or TIM, which measures the total solar irradiance (TSI) that is incident at the outer boundaries of the atmosphere; and the Spectral Irradiance Monitor, or SIM, which measures solar spectral irradiance (SSI) from 200 nm to 2400 nm (96 percent of the TSI). The TSIS TIM and SIM are heritage instruments to those currently flying on the NASA Solar Radiation and Climate Experiment (SORCE). Both were selected as part of the TSIS because of their unprecedented measurement accuracy and stability, and because both measurements are essential to constraining the energy input to the climate system and interpreting the response of climate to external forcing. TSIS is required in order to continue the 33-year record of TSI, extend the newer 8-year record of SSI, and insure the stewardship of the solar irradiance Climate Data Record into the future.

Quick Facts

Launch date: July, 2016
Launch location: TBD
Launch vehicle: TBD
Mission target: Low Earth orbit
Mission duration: 5 years
Other key dates:
Other organizations involved:

  • NASA’s Goddard Space Flight Center (GSFC)
  • National Oceanic and Atmospheric Administration