Naval operations, including day-to-day activities as well as warfighting, depend upon the environment and are planned and executed based upon environmental knowledge. Hyperspectral sensing provides environmental information and characterization for some of these operational Naval activities. It is useful to separate these information types into "oceanographic" and "meteorological" categories as follows:
(1) Coastal and shallow water operations,
(2) Beach, wetland and near shore operations,
(3) Self defense, and
(4) Precision strike.
The design strategy for environmental satellite constellations relies upon low orbiting satellites to provide global, high-resolution synoptic data and geostationary satellites to provide continuous observations of rapidly evolving local events. The latter category includes storm systems and, with the advent of cloud-track and water vapor winds, winds aloft. This division of labor is an architectural convenience for visual and infrared sensors but a necessity for microwave sensors. In fact, the typical ground resolution of microwave sensors on low orbiters is barely acceptable. Unfortunately, microwave sensors are preferable to visual and infrared systems for many applications including sea-surface temperature and wind measurement and the only viable method for remotely sensing sea surface salinity. Microwave sensors are also preferable for some atmospheric sounding applications because they are relatively insensitive to cloud cover. The most important cases where microwave sensors are preferred, those related to diagnosing the evolution of severe storm activity, require the highest spatial resolution and are best done with geostationary satellites. In particular, microwave sounding would be an ideal capability for a geostationary weather satellite.
The end of the cold war has seen a shift in emphasis of Navy operations from a 'blue water' strategic role to a 'brown water' coastal role. The more changeable and complex coastal environment plus the need to operate first on scene in unfamiliar areas creates a need for environmental data which is best filled by remote sensing. This paper summarizes some of the Navy's most important and enduring environmental knowledge needs. Remote sensing from satellites, aircraft and ships will provide some of this environmental knowledge.
The polar ozone and aerosol measurement experiment (POAM II) was launched on the SPOT 3 satellite on 25 September 1993. POAM II is designed to measure the vertical profiles of the polar ozone, aerosols, water vapor, nitrogen dioxide, atmospheric density and temperature in the stratosphere and upper troposphere. It makes solar occultation measurements in nine channels defined by narrow-band filters. The field of view is 0.01 by 1.2 degrees, with an instantaneous vertical resolution of 0.6 km at the tangent point in the earth's atmosphere. The SPOT 3 satellite is in a 98.7-degree inclined sun-synchronous orbit at an altitude of 833 km. From the measured transmissions, it is possible to determine the density profiles of aerosols, O3, H2O, and NO2. Using the assumption of uniformly mixed oxygen, we are also able to determine the temperature. We present details of the POAM II instrument design, including the optical configuration, electronics and measurement accuracy. We also present preliminary results from the occultation measurements made to date.
A novel mm-wave radiometer system specifically designed for measuring water vapor in the stratosphere is presented. The instrument, which is based on an HEMT front-end amplifier, is described in detail. The data retrieval scheme and the results of an extensive instrument data simulation study are also presented. The device's principal features are its capability to conduct measurements of the water vapor profile simultaneously from 25-75-km altitude, with excellent long-term relative precision, and semiautomatically at a remote site.
Conference Committee Involvement (1)
Imaging Spectrometry IX
6 August 2003 | San Diego, California, United States