<title>Design and performance of the EO-1 Advanced Land Imager</title>

Abstract

An Advanced Land Imager (ALl) will be flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). The ALT contains a number of key NMP technologies. These include a 15° wide field-of-view, push-broom instrument architecture with a 12.5 cm aperture diameter, compact multispectral detector arrays, non-cryogenic HgCdTe for the short wave infrared bands, silicon carbide optics, and a multi-level solar calibration technique. The focal plane contains multispectral and panchromatic (MSIPan) detector arrays with a total of 10 spectral bands spanning the 0.4 to 2.5 jim wavelength region. Seven of these correspond to the heritage Landsat bands. The instantaneous fields of view of the detectors are 14.2 prad for the Pan band and 42.6 p.rad for the MS bands. The partially populated focal plane provides a 3° cross-track coverage corresponding to 37 km on the ground. The focal plane temperature is maintained at 220 K by means of a passive radiator. The instrument environmental and performance testing has been completed. Preliminary data analysis indicates excellent performance. This paper presents an overview of the instrument design, the calibration strategy, and results of the pre-flight performance measurements. It also discusses the potential impact of ALT technologies to future Landsat-like instruments.

ASTER, ALI and Hyperion sensors data for lithological mapping and ore minerals exploration

“…The performance characteristics of the ALI and ETM + are shown in Table 2 . Additional bands in the ALI improved Signal-to-Noise Ratio (SNR) that is one of the most significant performance aspects of the ALI to increase the quality of data (Lencioni et al, 1999 ; Mendenhall et al 2000 ; Thome et al, 2003 ; Lobell and Asner 2003 ).…”

Cooling capacity of high porosity open-cell metal foams as passive cryogenic radiators

“…These have been instrumental in providing cooling to detectors (80-300 K [22,5]), camera focal planes (220 K [23], 160 K [24]), instrument optics (267 K [25]) and electronics (265 K [12]). However, below 80 K temperature [9,20], passive radiators have to be pooled along with active cryocoolers such as sorption coolers and Joule-Thompson refrigerators, so as to achieve low temperatures [6,9,14,16,[17][18][19]20,[26][27][28][29][30].…”

Radiometric calibration of Advanced Land Imager using reflectance-based results between 2001 and 2005

“…Differences in ALI relative to ETM+ include the addition of three bands, panchromatic resolution improvement, and a higher 12-bit quantization. 3 Table 1 presents the center wavelengths of the solar-reflective bands of TM, ETM+ and ALI. One fundamental difference between ALI and previous Landsat instruments is that it is a pushbroom system rather than a whiskbroom.…”

“…Another distinct improvement of ALI is that the more technologically advanced design has about one-fourth the mass, one-fifth the power consumption, and about one-third the volume of Landsat 7. 3 A valuable aspect of the Landsat mission is that it is a continuous set of Earth data that is radiometrically calibrated. Many users of remote sensing products study the imagery provided by Landsat to detect changes in the environment over time.…”