Sensors - Advanced Land Imager (ALI)

The EO-1 ALI is the first Earth-Observing instrument to be flown under NASA's New Millennium Program (NMP). The ALI employs novel wide-angle optics and a highly integrated multispectral and panchromatic spectrometer.

EO-1 is a technology verification project designed to demonstrate comparable or improved Landsat spatial and spectral resolution with substantial mass, volume, and cost savings.
MIT Lincoln Laboratory developed the ALI with NMP instrument team members: Raytheon/Santa Barbara Remote Sensing (SBRS) for the focal plane system, and Sensor Systems Group, Inc. (SSG) for the optical system.

Instrument Overview

The EO-1 ALI is a technology verification instrument under the NMP. The focal plane for this instrument is partially populated with four sensor chip assemblies (SCA) and also covers 3° by 1.625°. Operating in a pushbroom fashion at an orbit of 705 km, the ALI provides Landsat type panchromatic and multispectral bands. These bands have been designed to mimic six Landsat bands with three additional bands covering 0.433-0.453, 0.845-0.890, and 1.20-1.30 µm. The ALI also contains wide-angle optics designed to provide a continuous 15° x 1.625° field of view for a fully populated focal plane with 30-meter resolution for the multispectral pixels and 10-meter resolution for the panchromatic pixels.


ALI visual representation of the Silicon Carbide (SIC) optics contained in the sensor.

Band	Wavelengh(µm)	Ground Sample Distance(m)
Pan	0.48 - 0.69	10
MS - 1'	0.433 - 0.453	30
MS - 1	0.45 - 0.515	30
MS - 2	0.525 - 0.605	30
MS - 3	0.63 - 0.69	30
MS - 4	0.775 - 0.805	30
MS - 4'	0.845 - 0.89	30
MS - 5'	1.2 - 1.3	30
MS - 5	1.55 - 1.75	30
MS - 7	2.08 - 2.35	30

The following key technologies are incorporated in the ALI instrument to achieve its dramatic cost, weight, and performance advantages:

• Silicon Carbide Optics
• Wide Field of View Optics
• Multispectral Imaging Capability

Benefit

The ALI technologies will enable the reduction of mass, power, complexity, and cost of future Earth imaging systems. A fully operational ALI has the potential for reducing the cost and size of future Landsat-type instruments by a factor of 4 to 5.