The Far Infrared Spectrum of Water Vapor

Absorption spectrum of water vapor between 4.5 and 13 microns

“…For completeness, there are included lower lines of the series, as observed by other investigators [12,13] in the farther infrared, as well as frequencies, in parentheses, of lines that have not yet been measured with high accuracy. A comparison with table 1 again shows that the suggested array accounts for most of the observed lines from 760 to 1,000 em-I, with the lines that are most enhanced in the atmosphere belonging, for the most part, to the more hi~hly forbidden R5 ;; and R5 :;; series.…”

Investigations in the Far-Infrared With a Lamellar Grating Interferometer

“…The ranges of L and Ax weire chosen to be representative for the FIR region. Equation (45) predicts that, if Ax in decreased (or vc multiplied) by a factor R, the noise in ýhe spectrum will be reduced by a factor R The number of points will of course be increased by R (for constant L). Thus, if the same amount of time is available for the measurements, N, will be resulting in no change for N .…”

Reference wavelengths for calibrating prism spectrometers

“…Absorption sp ectrum of didymium glass, 6 millimeters thicle, in the Tegion from 0.6 to 2 microns. Pol~-sL}Ten e fllms ar e easily made, and Llle spectrum is su itable 1'0 1' a chec k of t he in strument .…”

“…Th e atmospheric-water-vapor lines ill the vibrational rotational band are no t properly r esolved with prism instruments, but the pure rotation spectrum from 20 to 150 J.i-is well sui ted for calibration. These lines have b een m eas ured by Randall, D ennison , G insburg, and vveber [6], and th eir ar ticle lists the observed wavelengths_…”