Yuji Miyachi

Calibration of advanced visible and near infrared radiometer

Calibration results of the advanced visible and near infrared radiometer (AVNIR) on board ADEOS are presented. First, the AVNIR responses to the internal and external calibration sources are evaluated, and their short- and long-term stabilities are summarized. Second, absolute radiometric calibration of AVNIR is conducted by using the NASA JPLs calibrated airborne optical sensor, and the results from several different calibration methods (preflight calibration, and in-flight calibrations using the on-board data, the AVIRIS, and the vicarious method) are compared. Third, the geometric accuracy and the image quality are summarized.

POLDER-OCTS preflight cross-calibration experiment using round-robin radiometers

This joint article presents the POLDER-OCTS preflight cross-calibration procedure and data set. POLDER is a radiometer developed by CNES devoted to the measurement of the polarization and directionality of the Earths reflectances and OCTS is an ocean color and temperature scanner developed by NASDA. Both radiometers are onboard the ADEOS satellite to be launched in 1996. The preflight POLDER-OCTS cross-calibration experiment was carried out by NRLM, NASDA, and CNES from March to April in 1994 using round- robin radiometers. The cross-calibration results show the agreement between NRLM/NASDA and CNES radiometers better than 6% regarding POLDER integrating sphere at CNES in Toulouse and better than 5% regarding OCTS integrating sphere at NEC in Yokohama. Calbration of OCTS integrating sphere by NEC agreed with cross calibration by NRLM/NASDA within 3%. The calibration of CNES round-robin radiometer is guaranteed at 3.5%.

Ocean color and temperature scanner for ADEOS

Design of the OCTS, a high-precision remote-sensing instrument for NASDAs Advanced Earth Observing Satellite (ADEOS) for simultaneous measurements of the ocean color and sea-surface temperatures, is presented. The OCTS uses a rotating mirror to scan a swath of the earth 1400 km wide from sun-synchronous orbit at 800 km altitude. It is planned to be placed into orbit in 1995 to provide 3 Mbps image data for visible to thermal infrared spectral range, in 12 bands.

Calibration of advanced visible and near infrared radiometer (AVNIR)

Abstract Initial on‐orbit calibration results of the advanced visible and near infrared radiometer (AVNIR) onboard ADEOS were presented. When ADEOS returned over the Japan ground station mask on Sept. 11996, AVNIR was first activated to evaluate performance. AVNIR calibration toas then conducted using the reference signal sources (internal lamps, natural target data, NASAs airborne sensor data, etc). The evaluation indicated that AVNIR has sufficient sensitivity to function as a high‐resolution imager and is useful for the land monitoring, though some noises are to be removed.

Status of ADEOS mission sensors

Abstract The main objectives of the Advanced Earth Observation Satellite (ADEOS) are to contribute to global observation of environmental change with the international community as well as to establish future platform technologies. To achieve these objective, ADEOS will carry two core sensors developed by NASDA, the Ocean Color and Temperature Scanner (OCTS) and the Advanced Visible and Near-Infrared Radiometer (AVNIR), and six Announcement of Opportunity (AO) sensors, the Interferometric Monitor for Greenhouse Gases (IMG) provided by the Ministry of International Trade and Industry of Japan, the Improved Limb Atmospheric Spectrometer (ILAS) and the Retroreflector In Space (RIS) provided by the Environment Agency of Japan, the NASA Scatterometer (NSCAT) and the Total Ozone Mapping Spectrometer (TOMS) provided by NASA, and the Polarization and Directionality of the Earths Reflectances (POLDER) provided by CNES. ADEOS, for which basic design began last summer, is scheduled to be launched into sun synchronous orbit from Tanegashima Space Center by H-II rocket in early 1995. The interface coordination between ADEOS and mission sensors was the most important topic of this international cooperative project. This paper reports the status of the ADEOS mission sensors from the viewpoint of the interface coordination, and addresses the outline and development status of NASDA core sensors.

Calibration of OCTS

The calibration results of the ocean color temperature scanner (OCTS) onboard the Japanese advanced Earth observing satellite (ADEOS) are presented in this paper. The goal of OCTS is to measure the geophysical quantities of the ocean (chlorophyll-a concentration, pigment concentration, etc.). They are calculated from the measured radiance by correcting molecular and aerosol scattering components, so the highly accurate calibration of the OCTS data is desired. For this purpose, OCTS is radiometrically calibrated using internal calibration sources (i.e., internal lamps, sun light, night times data, uniform target data), and external calibration source (NASAs airborne sensor underflights). It is also calibrated using the ground control points. As a result it was confirmed that OCTS data meets the specifications and provides accuracy for scientific use.

Calibration of ocean color temperature scanner (OCTS)

Abstract The calibration results of the Ocean Color Temperature Scanner (OCTS) onboard the Japanese Advanced Earth Observing Satellite (ADEOS) are presented in this paper. The goal of OCTS is to measure the geophysical quantities of the ocean (Chlorophyll‐a concentration, pigment concentration, etc.). They are calculated from the measured radiance by correcting molecular and aerosol scattering components, so the highly accurate calibration of the OCTS data is desired. For this purpose, OCTS is radiometrically calibrated using internal calibration sources (i.e., internal lamps, sun light, night times data, uniform target data), and external calibration source (NASAs airborne sensor underflights). It is also calibrated using the ground control points. As a result it was confirmed that OCTS data meets the specifications and provides accuracy for scientific use.

Calibration of AVNIR

Initial on-orbit calibration results of the advanced visible and near infrared radiometer (AVNIR) onboard ADEOS were presented. When ADEOS returned over the Japan ground station mask on Sept. 1, 1996, AVNIR was first activated to evaluate performance. AVNIR calibration was then conducted using the reference signal sources (internal lamps, natural target data, NASAs airborne sensor data, etc.). The evaluation indicated that AVNIR has sufficient sensitivity to function as a high- resolution imager and is useful for the land monitoring, though some noises are to be removed.

High-resolution CCD linear image sensors for the advanced visible and near-infrared radiometer (AVNIR)

Two types of high resolution CCD linear image sensors have been developed for AVNIR, which will be carried on the Advanced Earth Observing Satellite (ADEOS) in early 1996. One has 10000 pixels (pixel size: 8 micrometers X 8 micrometers ) with spacing of 8 micrometers for the panchromatic band (0.52 - 0.69 micrometers ). The other has 5000 pixels (pixel size: 16 micrometers X 16 micrometers ) with spacing of 16 micrometers for the multispectral bands (Mu1: 0.42 - 0.50 micrometers , Mu2: 0.52 - 0.60 micrometers , Mu3: 0.61 - 0.69 micrometers , and Mu4: 0.76 - 0.89 micrometers ). These bands are separated by a dichroic prism in the optical system. Each sensor has a staggered layout of Si p-n-p buried photodiodes, and an overflow drain for an anti- blooming and an electronic shutter operation. The sensor for the multispectral band (MU) has 2 CCDs and the sensor for the panchromatic band (PA) has 4 CCDs to reduce operating frequency. To prevent degradation of modulation transfer function (MTF) for the Mu4 band, which is a near-infrared region, we used a staggered arrangement and p- on p+ epitaxial wafers. MTF in Mu4 band is 0.62 and 0.80 at Nyquist frequency (fn) and 1/2 fn, respectively. We have developed novel packaging technologies so as to obtain a focal plane flatness of less than 10 micrometers peak-to-peak. These technologies include a newly developed SiC-Al2O3-SiC package and a method to correct a warp of the chip surface.

Advanced visible and near-IR radiometer for ADEOS

The current status of an advanced visible and near infrared radiometer (AVNIR) planned to be launched onboard Advanced Earth Observing Satellite in 1995 is described. The AVNIR is intended to observe land and coastal zones to monitor different phenomena including desertization and destruction of tropical forest.