Imaging Photometer

The MIPS for SIRTF will provide diffraction-limited imaging over the wavelengths between 20 and 180 /rm. This range is covered by three detector arrays optimized 

The InfraRed Array Camera (IRAC) provides imaging at shorter wavelengths with bands centered at 3.6, 4.5, 5.8 and 8.0 /txm. The 3.6 and 4.5 fim bands utilize two 256 X 256 pixel In Sb detector arrays while the two longer bands utilize 256 x 256 pixel Si As impurity band conduction detectors. Although there are four photometric bands IRAC has only two entrance apertures. Dichroic beam splitters allow the 3.6 and 5.8 band to share one aperture while the 4.5 and 8.0 bands share the other. This doubles the efficiency for multiband observations. 

The InfraRed Spectrograph (IRS) provides the primary spectroscopic capability for SIRTF. It covers the wavelength range of 5.3 to 40.0 /xm with low-resolution (7 = 60-120) spectroscopy and the range between 10 and 37 /txm at higher resolution R = 600). IRS utilizes 128 X 128 Si As and Si Sb BIB arrays to cover its wavelength region. 

---

MIPS Multi-band Imaging Photometer for Spitzer provides imaging capabilities in broad bands at 24, 70, and 160 am. In addition, the instrument has a low-resolution spectroscopic mode that operates between 55 and 95 pm. 

Fluorescence studies of plants were conducted on instruments developed in the lab, a fluorescence video imaging photometer (15) or a field flash kinetic fluorimeter (16). 

J. A. Swanstrom, L. S. Bruckman, M. R. Pearl, E. Abernathy, M. N. Simcock, K. A. Donaldson, T. L. Richardson, T. J. Shaw, and M. L. Myrick, Taxonomic Classification of Phytoplankton with Multivariate Optical Computing. Part 11. Design and Experimental Protocol of a Shipboard Fluorescence Imaging Photometer, Appl. Spectrosc., 67, 630 (2013). 

Multiband Imaging Photometer for SIRTF (MIPS) - G. Rieke, P.L, University of Arizona. Will use Si Sb and Ge Ga arrays for imaging and polarimetry, and use a scanning minor to rapidly survey large areas. IBAC also considering scan mirror. 

The Space Infrared Telescope Facility (SIRTF) is our first opportunity to use hi performance infrared arrays on a cooled telescope, where they can reach sensitivity leveb determined only by the environment of the earth in space - that is, by emissions from the zodiacal doud, the Milky Way, or distant galaxies. From space, we are no longer restricted in spectral coverage. To increase the power of SIRTF and to provide a reasonable match of capabilities across its operating range, the MIPS (Multiband Imaging Photometer for SIRTF) team has imdertaken the development of far infrared arrays. This effort has produced the first high performance far infrared photoconductor array evex built. 

Emission ratio imaging is extremely popular due to its simplicity and speed. In essence, cells expressing donors and acceptors are illuminated at the donor wavelength and fluorescence intensity data are collected both at donor (D) and at acceptor (S) channels. Collected data may be either images, or, in case high acquisition speed is crucial and spatial information is not required, dualchannel photometer readings (see Textbox 1). S and D are not overlap-corrected and FRET is simply expressed as the ratio of intensities1 as ratio = S/D. 

For almost any experiment that involves a light microscope, quantitative data to test a hypothesis may be obtained by microphotometry. Add a photometer and a few accessories to a light microscope, and it may be possible to quantify a cytochemical reaction product, measure the spectrum of a pigment, quantify natural or induced fluorescence, quantify birefringence, or map and analyze an image. But manually collecting thousands of numbers is unbelievably tedious. The solution is obvious. Use a personal computer (PC) to collect the numbers. 

Photometries, Ltd. Scientific imaging products Tucson, Arizona, U.S.A. Tel 1-520-889-9933, fax 1-520-573-1944, http //www.photomet.com... 

Over the past decade, there has been considerable development in imaging type detectors for the measurement of ultraviolet (UV) and visible light. These new detectors have attracted the interest of a number of analytical spectroscopists. For absorption spectroscopy, analytical chemists have traditionally used such instruments as the photometer, which uses a narrow-band light source (for example the 254 nm emission line from a low pressure Hg lamp or a continuous source with a filter), a sample cell and a photomultiplier tube (FMT) as the detector. While useful for many specific applications, the single-wavelength photometer cannot determine multiple sample components simultaneously or provide a general absorbance characterization of the system. When information at multiple wavelengths is desired,... 

This approach, when compared with (ii) with respect to signal-to-noise ratio, has the multi-channel advantage each wavelength is measured continuously and no loss in measurement time occurs. Nevertheless, these systems are inferior to normal photometers, as all photo-receptors capable of image-sensing operation (photodiode array, vidicon, etc.) show a poorer signal-to-noise ratio in comparison with vacuum phototubes and photomultipliers. 

A rectangular array of spots is written and the large-area CR of the projected image is measured with a photometer. The laser beam is focused to about 10x15 ym and is modulated with an A/0... 

Table 2 shows an example calculation of all the aforementioned criteria for the scene in Fig. 8. The resulted values are comprehensible the very low amount of light, evident by the luminance value and the value measured by the photometer, leaves some parts of the image completely dark. The rather high PSNR value is also allegeable, although some noise can clearly be seen (e.g. on the white plan surface... 

---