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Mauldin, L. E., III

Publications and source records attributed to Mauldin, L. E., III.

11 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Sun sensor boresight alignment testing for the Halogen Occultation Experiment

The boresight alignment testing for the sun sensor assembly on the Halogen Occultation Experiment (HALOE) is described. The sun sensor assembly consists of three sensors that provide feedback signals for controlling dual axes gimbals. Two energy balancing silicon detectors are operated as wideband sensors in the azimuth and elevation axes. The third sensor is a silicon photodiode array operated as a narrow-band sensor in the elevation axis. These sensors are mounted on a common Invar structure which is mounted to the HALOE telescope. A blackbody was used as the stimulating source to perform the initial boresight alignment and this was checked with a heliostat solar look and a direct solar look. These tests are explained with a comparison between each source used.

Moore, A. S.↗
NASA NTRS1987

Digital solar edge tracker for the Halogen Occultation Experiment

The optical and electronic design of the Halogen Occultation Experiment (Haloe) elevation sun sensor is described. The Haloe instrument is a gas-correlation radiometer now being developed at NASA Langley for the Upper Atmosphere Research Satellite. The system uses a Galilean telescope to form a solar image on a linear silicon photodiode array. The array is a self-scanned monolithic CCD. The addresses of both solar edges imaged on the array are used by the control/pointing system to scan the Haloe science instantaneous field of view (IFOV) across the vertical solar diameter during instrument calibration and then to maintain the science IFOV 4 arcmin below the top edge during the science data occultation event. Vertical resolution of 16 arcsec and a radiometric dynamic range of 100 are achieved at the 700-nm operating wavelength. The design provides for loss of individual photodiode elements without loss of angular tracking capability.

Mauldin, L. E., III↗
NASA NTRS1986

Halogen occultation experiment (HALOE) performance verification test procedure

The Performance Verification Test Procedure is given for the Halogen Occultation Experiment (HALOE) instrument, which is being developed in house at the Langley Research Center for the Upper Atmosphere Research Satellite (UARS). This procedure is used for comprehensive performance testing of the HALOE instrument which occurs before, during, and after flight environmental tests. The radiometric performance tests include noise, drift, linearity, instantaneous field-of-view, cal wheel gas cell characterization, and self thermal emissions. Pointer/tracker performance tests include sun sensor performance, gimbal performance, control system performance, and boresight alignment. In addition, the instrument is tested functionally in simulated orbit sequences and all command operating modes are exercised. The data analysis required for each test is specified and pass/fail criteria are given where applicable. This test will fully demonstrate the HALOE instrument's ability to achieve science mission requirements. The HALOE instrument is a gas correlation radiometer that measures vertical distribution of eight upper atmospheric constituents: O3, HCl, HF, NO, CH4, H2O, NO2, and CO2.

Mauldin, L. E., III↗
NASA NTRS1986

Halogen occultation experiment intergrated test plan

The test program plan is presented for the Halogen Occultation Experiment (HALOE) instrument, which is being developed in-house at the Langley Research Center for the Upper Atmosphere Research Satellite (UARS). This comprehensive test program was developed to demonstrate that the HALOE instrument meets its performance requirements and maintains integrity through UARS flight environments. Each component, subsystem, and system level test is described in sufficient detail to allow development of the necessary test setups and test procedures. Additionally, the management system for implementing this test program is given. The HALOE instrument is a gas correlation radiometer that measures vertical distribution of eight upper atmospheric constituents: O3, HC1, HF, NO, CH4, H2O, NO2, and CO2.

Mauldin, L. E., III↗
NASA NTRS1986

The Stratospheric Aerosol and Gas Experiment II (SAGE II) design and in-orbit performance

The design and in-orbit performance data are presented for the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument which was launched by Shuttle on the Earth Radiation Budget Satellite. SAGE II is a sun photometer that measures the extinction of solar radiation caused by the earth's atmosphere in seven spectral channels ranging in center wavelength from 0.385 to 1.02 micrometers. These measurements, which occur twice each orbit during satellite sunrise and sunset, are inverted to yield vertical distributions of stratospheric aerosols, ozone, water vapor, and nitrogen dioxide. The SAGE II instrument consists of a Cassegrain telescope with a two axis gimbal mounting, a grating spectrometer, and a 12 bit data system. The instrument tracks the solar centroid in the azimuth plane and vertically scans the instrument's instantaneous field of view across the sun for tangent altitudes ranging from the earth's horizon to 150 km. SAGE II is a third generation instrument following the highly successful Stratospheric Aerosol Measurement II (SAM II) and SAGE I programs.

Mauldin, L. E., III↗
NASA NTRS1986

Design and performance of the halogen occultation experiment (HALOE) remote sensor

HALOE is an optical remote sensor that measures extinction of solar radiation caused by the earth's atmosphere in eight channels, ranging in wavelength from 2.5 to 10.1 microns. These measurements, which occur twice each satellite orbit during solar occultation, are inverted to yield vertical distributions of middle atmosphere ozone (O3), water vapor, nitrogen dioxide, nitric oxide, hydrogen fluoride, hydrogen chloride, and methane. A channel located in the 2.7 region is used to infer the tangent point pressure by measuring carbon dioxide absorption. The HALOE instrument consists of a two-axis gimbal system, telescope, spectral discrimination optics and a 12-bit data system. The gimbal system tracks the solar radiometric centroid in the azimuthal plane and tracks the solar limb in the elevation plane, placing the instrument's instantaneous field-of-view 4 arcmin down from the solar top edge. The instrument gathers data for tangent altitudes ranging from 150 km to the earth's horizon. Prior to an orbital sunset and after an orbital sunrise, HALOE automatically performs calibration sequences to enhance data interpretation. The instrument is presently being tested at the NASA Langley Research Center in preparation for launch on the Upper Atmosphere Research Satellite near the end of this decade. This paper describes the instrumenmt design, operation, and functional performance.

Baker, R. L.↗
NASA NTRS1985

Application of a silicon photodiode array for solar edge tracking in the Halogen Occultation Experiment

The optical and electronic design of the Halogen Occultation Experiment (HALOE) elevation sunsensor is described. This system uses a Galilean telescope to form a solar image on a linear silicon photodiode array. The array is a self-scanned, monolithic charge coupled device. The addresses of both solar edges imaged on the array are used by the control/pointing system to scan the HALOE science instantaneous-field-of-view (IFOV) across the vertical solar diameter during instrument calibration, and then maintain the science IFOV four arcmin below the top edge during the science data occultation event. Vertical resolution of 16 arcsec and a radiometric dynamic range of 100 are achieved at the 0.7 micrometer operating wavelength. The design provides for loss of individual photodiode elements without loss of angular tracking capability. The HALOE instrument is a gas correlation radiometer that is now being developed by NASA Langley Research Center for the Upper Atmospheric Research Satellite.

Mauldin, L. E., III↗
NASA NTRS1983

Design and performance of the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument

Design and performance data are analyzed for the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument, which has been developed for the NASA Earth Radiation Budget Satellite (ERBS). SAGE II is designed to monitor globally, from 70 degrees S to 70 degrees N latitude, the vertical distribution of stratospheric aerosols, ozone, water vapor, and nitrogen dioxide by measuring the extinction of solar radiation through the earth's atmosphere during the ERBS observatory solar occultations. A flat scanning mirror reflects solar radiation into a Cassegrain type telescope, which forms a solar image on the entrance slit of a grating spectrometer. The instantaneous-field-of-view of the SAGE II is scanned along the vertical solar diameter by the elevation scan mirror. The optical system is contained within an azimuth gimbal which tracks the solar radiometric centroid during the data event, while the spectrometer isolates seven spectral wavelengths from 0.385-1.02 micrometers. The seven channels of the spectrometer use silicon photodiode dedectors operated in the photovoltaic mode. The detector outputs are multiplexed into a serial data stream for readout by the ERBS telemetry system, with each output being sampled 64 times per second and digitized to 12 bit resolution.

Zaun, N. H.↗
NASA NTRS1982

Optical degradation due to contamination on the SAGE/SAGE II spacecraft instruments

An optical model for contamination effects has been developed for the SAGE II/ERBS instrument. This model describes instrument throughput efficiency and response characteristics as a function of molecular contamination thickness for indexes of refraction representative of Shuttle/ERBS/SAGE II contaminants at seven spectral wavelengths between 0.385 and 1.02 micrometers. Contamination effects are treated as thin film coatings on selected optical elements which cause changes in those elements' reflection/transmission/absorption characteristics. SAGE/AEM in-orbit performance data were used to estimate the optical constants for the contaminants. SAGE and SAGE II are radiometers that spatially scan the sun through the earth's atmosphere with a narrow field-of-view in spectral intervals from visible to the near infrared.

Mauldin, L. E., III↗
NASA NTRS1978

Stratospheric Aerosol Measurement (SAM 2) experiment

The Stratospheric Aerosol Measurement 2 (SAM 2) is used to map the concentration and optical properties of stratospheric aerosols as a function of altitude, latitude, and longitude. The vertical distribution of the stratospheric aerosols in the polar regions of both hemispheres is provided.

Mccormick, M. P.↗