Abstract
INTRODUCTION: The Ozone Mapping and Profiler Suite (OMPS) instrument provides long-term stratospheric ozone monitoring capability for the Joint Polar Satellite System (JPSS). The JPSS OMPS instrument consists of two nadir-viewing, hyperspectral spectrometers that provide total column ozone and ozone vertical profile measurements. The first flight model of OMPS is currently on-orbit aboard the Suomi National Polar-orbiting Partnership satellite (S-NPP). The ground radiometric calibration of the OMPS instruments is discussed, which includes an overview of techniques for transferring the calibration of NIST primary standards to OMPS, in addition to a summary of the calibration uncertainties that were accounted for.
OMPS SENSOR OVERVIEW: OMPS is one of five instruments that launched aboard the S-NPP satellite in 2011. A second OMPS flight unit is being built by Ball Aerospace and will fly on the Joint Polar Satellite System-1 (JPSS-1), which will launch in 2016. OMPS is a three-part instrument suite: a nadir mapper that maps global ozone with roughly 50-km ground resolution, a nadir profiler that measures the vertical distribution of ozone in the stratosphere, and a limb profiler that measures ozone in the upper troposphere and lower stratosphere with high vertical resolution [1,2]. OMPS supports operational weather capabilities by measuring the global distribution of total atmospheric ozone, and ozone concentration variability with altitude.
CALIBRATION TECHNIQUES: Radiometric calibration of the OMPS spectrometer is performed on the ground by transferring the calibration of NIST primary standards to each of the sensors. OMPS is calibrated in both radiance and irradiance modes so that albedo measurements can be resolved on-orbit. On-orbit, calibration is maintained using solar measurements [3]. Each instrument has two diffusers: a working diffuser that is deployed routinely for the purpose of solar calibration, and a reference diffuser that is deployed sparingly for the purpose of monitoring working diffuser performance degradation.
S-NPP PERFORMANCE: S-NPP OMPS began acquiring data on January 2012 and has continued to perform well. OMPS total column measurements have been compared to Aura OMI and EOS MLS results [4,5]. The OMPS ozone map measurements after one month of operation were consistent with OMI, and OMPS data were in agreement with EOS MLS calculated reflectances to within 1% for wavelengths > 312 nm [5].
REFERENCES: [1] Dittman, Michael G., et al. "Nadir ultraviolet imaging spectrometer for the NPOESS Ozone Mapping and Profiler Suite (OMPS)." Proceedings of SPIE. Vol. 4814. 2002. [2] Dittman, Michael G., et al. "Limb broad-band imaging spectrometer for the NPOESS Ozone Mapping and Profiler Suite (OMPS)." Proceedings of SPIE. Vol. 4814. 2002. [3] Remund, Quinn P., et al. "The ozone mapping and profiler suite (OMPS): on-orbit calibration design." Fourth International Asia-Pacific Environmental Remote Sensing Symposium 2004: Remote Sensing of the Atmosphere, Ocean, Environment, and Space. International Society for Optics and Photonics, 2004. [4] Jaross, G., et al. "Initial results from the Ozone Mapper Profiler Suite on the Suomi National Polar-Orbiting Partnership." Geoscience and Remote Sensing Symposium (IGARSS), 2012 IEEE International. IEEE, 2012. [5] Jaross, Glen, et al. "Suomi NPP OMPS Limb Profiler initial sensor performance assessment." SPIE Asia-Pacific Remote Sensing. International Society for Optics and Photonics, 2012.
ACKNOWLEDGEMENTS: This work is funded under a contract to Ball Aerospace from NASA. The authors wish to thank and congratulate all NASA, NOAA, and Ball Aerospace contributors to OMPS, who helped make it a successful sensor.
Pre-Launch Radiometric Calibration of the Ozone Mapping and Profiler Suite (OMPS) Instruments
INTRODUCTION: The Ozone Mapping and Profiler Suite (OMPS) instrument provides long-term stratospheric ozone monitoring capability for the Joint Polar Satellite System (JPSS). The JPSS OMPS instrument consists of two nadir-viewing, hyperspectral spectrometers that provide total column ozone and ozone vertical profile measurements. The first flight model of OMPS is currently on-orbit aboard the Suomi National Polar-orbiting Partnership satellite (S-NPP). The ground radiometric calibration of the OMPS instruments is discussed, which includes an overview of techniques for transferring the calibration of NIST primary standards to OMPS, in addition to a summary of the calibration uncertainties that were accounted for.
OMPS SENSOR OVERVIEW: OMPS is one of five instruments that launched aboard the S-NPP satellite in 2011. A second OMPS flight unit is being built by Ball Aerospace and will fly on the Joint Polar Satellite System-1 (JPSS-1), which will launch in 2016. OMPS is a three-part instrument suite: a nadir mapper that maps global ozone with roughly 50-km ground resolution, a nadir profiler that measures the vertical distribution of ozone in the stratosphere, and a limb profiler that measures ozone in the upper troposphere and lower stratosphere with high vertical resolution [1,2]. OMPS supports operational weather capabilities by measuring the global distribution of total atmospheric ozone, and ozone concentration variability with altitude.
CALIBRATION TECHNIQUES: Radiometric calibration of the OMPS spectrometer is performed on the ground by transferring the calibration of NIST primary standards to each of the sensors. OMPS is calibrated in both radiance and irradiance modes so that albedo measurements can be resolved on-orbit. On-orbit, calibration is maintained using solar measurements [3]. Each instrument has two diffusers: a working diffuser that is deployed routinely for the purpose of solar calibration, and a reference diffuser that is deployed sparingly for the purpose of monitoring working diffuser performance degradation.
S-NPP PERFORMANCE: S-NPP OMPS began acquiring data on January 2012 and has continued to perform well. OMPS total column measurements have been compared to Aura OMI and EOS MLS results [4,5]. The OMPS ozone map measurements after one month of operation were consistent with OMI, and OMPS data were in agreement with EOS MLS calculated reflectances to within 1% for wavelengths > 312 nm [5].
REFERENCES: [1] Dittman, Michael G., et al. "Nadir ultraviolet imaging spectrometer for the NPOESS Ozone Mapping and Profiler Suite (OMPS)." Proceedings of SPIE. Vol. 4814. 2002. [2] Dittman, Michael G., et al. "Limb broad-band imaging spectrometer for the NPOESS Ozone Mapping and Profiler Suite (OMPS)." Proceedings of SPIE. Vol. 4814. 2002. [3] Remund, Quinn P., et al. "The ozone mapping and profiler suite (OMPS): on-orbit calibration design." Fourth International Asia-Pacific Environmental Remote Sensing Symposium 2004: Remote Sensing of the Atmosphere, Ocean, Environment, and Space. International Society for Optics and Photonics, 2004. [4] Jaross, G., et al. "Initial results from the Ozone Mapper Profiler Suite on the Suomi National Polar-Orbiting Partnership." Geoscience and Remote Sensing Symposium (IGARSS), 2012 IEEE International. IEEE, 2012. [5] Jaross, Glen, et al. "Suomi NPP OMPS Limb Profiler initial sensor performance assessment." SPIE Asia-Pacific Remote Sensing. International Society for Optics and Photonics, 2012.
ACKNOWLEDGEMENTS: This work is funded under a contract to Ball Aerospace from NASA. The authors wish to thank and congratulate all NASA, NOAA, and Ball Aerospace contributors to OMPS, who helped make it a successful sensor.