The Hyper-Angular Rainbow Polarimeter-2 (HARP2) was launched on board the Plankton, Aerosol, Cloud and ocean Ecosystem (PACE) mission, in February 2024, for the global measurement of aerosol and cloud properties as well as to provide atmospheric correction over the footprint of the Ocean Color Instrument (OCI). HARP2 is designed to collect data over a wide field of view in the cross-track direction (+/-47deg) allowing for global coverage in about two days, as well as an even wider field of view in the along-track direction (+/-54deg) providing measurements over a wide range of scattering angles. HARP2 samples 10 angles at 440, 550, and 870nm focusing on aerosol and surface retrievals, and up to 60 angles at 670nm for the hyper-angular retrieval of cloud microphysical properties. The HARP2 instrument collects three nearly identical images with linear polarizers aligned at 0°, 45°, and 90° that can be converted to push-broom images of the I, Q, and U Stokes parameters for each angle, and each wavelength. The HARP2 technology was first demonstrated with the HARP CubeSat satellite which collected a limited dataset for 2 years from 2020 to 2022. HARP2 extends these measurements to a full global coverage in two days, seven days a week.
The Hyper-Angular Rainbow Polarimeter (HARP2) is a novel wide-field of view imaging polarimeter instrument on the recently-launched NASA Plankton Aerosol Cloud ocean Ecosystem (PACE) mission. Since launch on February 8 2024, HARP2 has taken over 6 months of global Earth data. In order for this data to meet scientific quality standards, we must ensure that it is as accurate as possible and over long periods of time. We use well-characterized Earth targets, such as Saharan deserts, as well as regular views of the Sun and dark frames to trend our on-orbit calibration. In this work, we discuss the preliminary performance trends derived from these activities and how well they compare with the HARP2 prelaunch calibration.
The Hyper-Angular Rainbow Polarimeter (HARP) Cubesat started data collection in April 2020 from the ISS orbit and is the first Hyper-Angular imaging polarimeter in space. The HARP payload produces pushbroom images at four wavelengths (440, 550, 670 and 870nm) with up to 60 viewing angles at 670 nm and up to 20 along track angles for the other three wavelengths. HARP swath consists of 94 degs in the cross track direction, allowing for a very wide coverage around the globe, and +/-57 degs in the along track direction, providing wide scattering angle sampling for aerosol and cloud particle retrieval. The HARP satellite is still active on orbit and so far have produce a large collection of scenes providing an unprecedented demonstration of the hyperangular retrieval of cloud and aerosol properties from space. This presentation will discuss the performance of the HARP sensor in space, as well as its first results for aerosol and cloud measurements. HARP is preceded by its airborne version, the AirHARP instrument, which has flown in two NASA aircrafts to demonstrate the capabilities of the HARP payload. The HARP payload is also a precursor to the HARP-2 polarimeter that will fly on the NASA PACE mission to collect global data on aerosol and cloud particles.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.