Comparison of the reflectivity and color of bright and dark regions on the surface of Mars.
Spectral reflectivity differences of selected dark and bright regions of Mars observed with double beam photometer
SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Spectral reflectivity differences of selected dark and bright regions of Mars observed with double beam photometer
Spectral reflectivity differences /color differences/ on lunar surface in visible region, indicating compositional difference origins
Photoelectric photometry observations of Jovian brightness variations over three year period
Remote sensing from aircraft and satellites of chlorophyll concentrations for monitoring of biological productivity of sea
Bicolor projections analogs with red and green McCollough aftereffects
Some simple calculations were made regarding the scattered light phenomenon of a sunlit earth limb. It was assumed that the light was to be scattered by an atmosphere irradiated by a zenith sun. Calculations were made with several different scattering coefficients assignable to various wavelengths of the extended visual region. The dependence of the excess blue-limb elevation was less obviously determined by the scattering angle than was suspected. It is reasonable to surmise that the variation of the values of excess blue-limb elevation originated principally from the red-limb variance, because the form of the blue-limb profiles (at least in their upper part) was more regular than was that of the red-limb profiles.
The all-sky, X-ray measurements are made in five broad energy bands from 0.5 to 60 keV with X-ray collimators of one and three degree FWHM response. Working with the onboard star sensor source locations may be determined to a precision of plus or minus 0.1 deg. The experiment is located in wheel compartment number three of the spacecraft. A time division logic system divides each wheel rotation into 256 data bins in each of which X-ray counts are accumulated over a 190 second interval. Measurement chain circuits include provision for both geometric and risetime anticoincidence. A detailed description of the instrument is included as is pertinent operating information.
Measurements made of the surface level albedo for ocean water containing various concentrations of phytoplankton indicate a strong correlation between wavelength dependent albedo ratios and phytoplankton chlorophyll concentration. To sense surface level albedo ratios from space platforms it is necessary to correct for the scattering and absorption properties of the atmosphere for the wavelengths in question. Atmospheric scattering models were constructed to calculate corrections at two wavelengths, 0.46 and 0.54 millimicrons. Assuming a natural background uncertainty in the aerosol optical depth of 0.1, it is found that the chlorophyll concentration may be determined to within one standard deviation of from 0.5 to 2.5 milligrams per cubic meter. By remotely sensing the aerosol optical depth to a greater accuracy it appears feasible to detect chlorophyll concentrations to uncertainty approaching 0.1 milligram per cubic meter.
Data for the 6300 A line of atomic oxygen from the main body airglow photometer on the OGO-D satellite are summarized in a set of 19 maps for various local times at night between 30 August 1967 and 10 January 1968.
The concept of monitoring the plankton-producing areas of the world is discussed in relation to assessing the exchange of CO2/O2 on a world-wide basis as a part of a life-support system.
Investigation of impurity-related electron-hole traps that are known to be sensitive to ionizing radiations. Electron spin resonance (ESR) equivalent natural doses were determined for the Al hole trap in virgin specimens; the doses agreed with estimates based on published data for the Ge electron trap. The 0.17 deg/sec 180 and 300 C thermoluminescence (TL) peaks in natural specimens were found to have activation energies approximately correct for the Ge trap. The 300 C peak was also found to be correlated with annealing of the Ge electron resonance in gamma-irradiated, step-annealed specimens. Although the 300 C peak occurs in virgin specimens, the corresponding natural Ge electron resonance was not observed.
An observation of the corona during the 7 March, 1970 eclipse through a Wollaston prism-red and blue filter combination was carried out for the purpose of confirming the prediction that the component of the K-corona with electric vector radial to the Sun is redder than the tangential component. An analysis of a portion of the resulting data seems to confirm this prediction, and also indicates that the method is useful for determining the three-dimensional configuration of the very inner corona. A three-dimensional configuration is suggested for a portion of the NE quadrant of the Sun, including the large NE streamer and an adjacent low-lying loop.
Explore the source record for details and available documents.
There are no author-identified significant results in this report.
The development of the television system used for Apollo 15 mission is discussed. Data cover identification of factors contributing to the high quality of pictures generated on the lunar surface and exploration of several possible present and future uses of the television equipment developed.
There are no author-identified significant results in this report.
There are no author-identified significant results in this report.
The author has identified the following significant results. Photo-optical and electronic density slicing were applied to ERTS-1 E 1007-151651-4, 30 July 1972, an area in the Caribbean showing deep ocean water, and shallow areas on the Great Baham Bank ranging from 0.5 meter or less to 18 meters. The density slicing processes were adjusted to correlate water radiance to bathmetric contours shown on C and GS Chart 1112. A number of large areas corresponding to water depths of 2 meters or less, 5 to 10 meters, and 10 to about 20 meters were isolated by both processes. Where clear water and uniformly reflective bottom was found, clear of marine growths, the photo-optical and electronic image density slicing processes proved effective in delineating areas where the depth was in the order of 5 meters, plus or minus 1 meter.