New Diviner Data including High Level Data Products available through NASA PDS
The Diviner team is providing new data relating to the surface characteristics of the moon. The data are available to the public through the Geoscience Node of the NASA Planetary Data System. The archived dataset includes Experimenter’s Data Records (EDR), Reduced Data Records (RDR), High Level Data Products and calibration and catalog information for the first 17 months of the mission. The High Level Data Products include gridded visual brightness and infrared brightness temperatures (Level 2); and derived fields such as rock abundance, nighttime regolith temperature and surface mineralogy, which will be created with the aid of topographic data and models (Level 3). The data are in the form of more than 1700 global digital maps at a range of resolutions that can be easily overlain on other lunar datasets. The PDS also provides a Diviner RDR Query tool that can be used to create maps and a Lunar Data Explorer tool that allows users to search for data from the Lunar Reconnaissance Orbiter, Clementine and Lunar Prospector Missions.
Diviner Channel 1 gridded visual brightness map for October, 2009. (1PPD)
Diviner Channel 7 gridded daytime brightness temperatures for October, 2009. (1PPD)
Diviner Channel 7 gridded nighttime brightness temperatures for October, 2009. (1PPD)
Bolometric temperature map (1PPD): The bolometric brightness temperature is a measure of the spectrally integrated flux of infrared radiation emerging from the surface. We use bolometric temperature rather than the brightness temperatures in the individual Diviner spectral channels because it is more directly related to the heat balance of the surface. Regardless of the complexity of the scene, if the region within a Diviner footprint is in a state of radiative equilibrium, then there will be a balance between the absorbed flux of solar radiation and the emitted flux of infrared radiation. Furthermore, since bolometric temperature is a measure of the spectrally integrated infrared flux leaving the surface, it is directly relevant to determining infrared heating rates in the shadowed regions of impact craters, where absorbed infrared radiation from warmer crater walls dominates the heat balance.
Diviner Global Rock Abundance Map (32PPD): Each sample represents the areal fraction of the surface covered by rock fragments as estimated using the technique described in Bandfield et al. (2011). Data is derived from Diviner data collected from July 5, 2009 through November 30, 2010. Data were restricted to local times of 1930 to 0530 with the solar incidence angles greater than 90 degrees, latitudes between 60N and 60S, emission angles less than 15 degrees, brightness temperatures less than 200K. Several data quality constraints were used as well (quality flag for calibration – 0; quality flag for miscellaneous – 0; noise quality flag – 0 to 1). Data from diviner spectral channels 6, 7, and 8 were binned at 32 pixels per degree in ten separate one hour increments of local time from 1930 to 0530. This map represents the 2230 bin. Because of the groundtrack walk and local time drift of Lunar Reconnaissance Orbiter observations, most surfaces are covered by only a single observation. In some cases, surfaces are covered by multiple observations acquired ~6 or 12 months apart.
Diviner Global Soil Temperature Map (32PPD): Each sample represents the rock-free regolith surface temperature as estimated using the technique described in Bandfield et al. (2011). Data is derived from Diviner data collected from July 5, 2009 through November 30, 2010. Data were restricted to local times of 1930 to 0530 with the solar incidence angles greater than 90 degrees, latitudes between 60N and 60S, emission angles less than 15 degrees, brightness temperatures less than 200K. Several data quality constraints were used as well (quality flag for calibration – 0; quality flag for miscellaneous – 0; noise quality flag – 0 to 1). Data from diviner spectral channels 6, 7, and 8 were binned at 32 pixels per degree in ten separate one hour increments of local time from 1930 to 0530. This map represents the 2230 bin. Because of the groundtrack walk and local time drift of Lunar Reconnaissance Orbiter observations, most surfaces are covered by only a single observation. In some cases, surfaces are covered by multiple observations acquired ~6 or 12 months apart.
Christiansen Feature Map (32PPD): The CF position is the wavelength of a major mid-infrared emissivity peak near 8-microns. It is a measure of silicate composition and shifts to shorter wavelengths for feldspathic lithologies (e.g. highlands) and longer wavelengths for mafic lithologies (e.g. maria). The CF position is also correlated with geochemical composition (generally shorter CF position for higher Si, Na, Ca and longer for higher Fe, Mg). The CF position is calculated from Diviner channels 3, 4, and 5 radiances. Each radiance is binned and averaged and then converted to brightness temperature. The three point brightness temperature spectrum is solved quadratically to determine the maximum brightness temperature. Emissivity values are then calculated for channels 3, 4, and 5. The emissivity spectrum is solved quadratically to determine the CF position.
Model-calculated depths at which water ice would be lost to sublimation at a rate of less than 1 kg/m2 per billion years.