Nimbus-7 coastal zone color scanner: system description and initial imagery.

The Coastal Zone Color Scanner (CZCS) on Nimbus-7, launched in October 1978, is the only sensor in orbit that is specifically designed to study living marine resources. The initial imagery confirms that CZCS data can be processed to a level that reveals subtle variations in the concentration of phytoplankton pigments. This development has potential applications for the study of large-scale patchiness in phytoplankton distributions, the evolution of spring blooms, water mass boundaries, and mesoscale circulation patterns.

Phytoplankton pigments from the nimbus-7 coastal zone color scanner: comparisons with surface measurements.

The removal of atmospheric effects from Nimbus-7 Coastal Zone Color Scanner (CZCS) images reveals eddy-like ocean turbidity patterns not apparent in the original calibrated images. Comparisons of the phytoplankton pigment concentrations derived from the corrected CZCS radiances with surface measurements agree to within less than 0.5 log C, where C is the sum of the concentrations of chlorophyll a plus phaeopigments a (in milligrams per cubic meter).

Infrared spectroscopy experiment on the mariner 9 mission: preliminary results.

The Mariner 9 infrared spectroscopy experiment has provided goodquality spectra of many areas of Mars, predominantly in the southern hemisphere. Large portions of the thermal emission spectra are significantly affected by dust with a silicon oxide content approximately corresponding to that of an intermediate igneous rock, thus implying that Mars has undergone substantial geochemical differentiation. Derived temperature profiles indicate a warm daytime upper atmosphere with a strong warming over the south polar cap. Atmospheric water vapor is clearly observed over the south polar area and less strongly over other regions.

Infrared reflectance of high altitude clouds.

The spectral reflectance characteristics of cirrostratus, cirrus clouds, and a jet contrail, in the 0.68-2.4-micro spectral interval, are of interest for remote sensing of cloud types from orbiting satellites. Measurements made with a down-looking spectrometer from a high altitude aircraft show differences between the signatures of naturally formed ice clouds, a fresh jet contrail, and a snow covered surface.

Infrared Aircraft Spectra Over Desert Terrain 8.5 micro to 16 micro.

Spectra in the 8.5-16-micro interval, taken at various altitudes over relatively uniform desert terrain, show attenuation of upwelling radiation by atmospheric gases and haze through the entire spectral interval. Equivalent blackbody temperatures, even in the clearest part of the window, show a drop that could introduce serious errors into remote sensing of surface temperatures. Surface emissivity characteristies are discernible at low altitudes but are somewhat masked by ozone at 10-km altitudes.

Filter wedge spectrometer for field use.

Two spectrometers, utilizing interference filter wedges, have been constructed for measurements under field conditions. One, operating from 1.6 micro. to 5.4 micro, has been flown unpressurized in an airplane to 12.2 km; the other, operating from 7.4 micro to 14.6 micro has been flown in a balloon to 33.3 km. Both instruments performed well, proving the interference filter wedge as avaluable tool for spectral measurements, especially in hostile environments.

Spectral measurements from 1.6 micro to 5.4 micro of natural surfaces and clouds.

A spectrometer, utilizing an interference filter wedge, has been used to obtain spectra of reflected solar and emitted thermal radiation from earth in the wavelength interval 1.6 micro to 5.4 micro. Measurements were made, from a jet aircraft, of characteristic spectra of a wide variety of surface and cloud conditions during day and night flights. Measurements made concurrently from the airplane and the Nimbus II meteorological satellite verified the accuracy of the Nimbus measurements.

Infrared spectral reflectance of some common minerals.

Infrared reflectance spectra of minerals of the carbonate, sulfate, nitrate, and silicate families exhibit spectral absorption band patterns that can be detected in reflection from surface minerals. These features could perhaps be used to identify such minerals from infrared reflection spectra of the moon and some planets; they might also be a source of confusion in interpretation of atmospheric spectra.

Optimum wavelength intervals for surface temperature radiometry.

Total reflectance measurements of some common surface minerals in the wavelength interval 0.5 micro to 23 micro show pronounced reflection maxima in some regions used for radiometric measurements of planetary surface temperatures. Variations in emissivity in the regions of such maxima could introduce significant errors into such temperature measurements. If measurements are restricted to the windows in the atmosphere of earth the 10-micro to 12-micro interval seems the best choice for radiometry since, in this interval, minerals are most uniformly black.