Uniform Calibration of Night Vision Goggles and Test Sets

Published

October 8, 2007

Author(s)

George P. Eppeldauer

Abstract

There are orders of magnitude differences between the ~0.1 % (k=2) uncertainty of NIST reference detector calibrations and the uncertainty of night vision (NV) goggle measurements. NIST developed a night vision radiometer calibration facility including NV radiometer transfer standards. The transfer standards, that propagate the radiance responsivity scale to the military primary standards laboratories, are calibrated against a NIST reference radiometer. The reference radiometer has been calibrated on the NIST Spectral Comparator Facility (SCF) for spectral power and irradiance responsivities. Spectral considerations are discussed to lower the uncertainties of the radiance responsivity scale transfer to the test sets and then to the goggles. Since direct determination of the final uncertainties in goggle calibrations and measurements is difficult, models have been made to estimate the most important uncertainty components based on individual spectral measurements of the applied source distributions and radiometer spectral responsivities. It is also shown, that because of source spectral mismatch problems, the goggle measurement uncertainty at applications can be much higher than at calibration. A suggestion is being made to mimic the no-moon (stars only) night sky radiation distribution using several LEDs in the test-sets to decrease the large spectral mismatch errors. A broad-band correction factor has been developed to further decrease calibration uncertainty when the goggles to be used have different spectral responsivities than the standard. Geometrical considerations to optimize the radiance measurement angle and the out-of-target blocking are also discussed to decrease the uncertainty in the radiance responsivity transfer.

Proceedings Title

SPIE Defense and Security Symposium | Europe | 2007 |

Volume

6737

Conference Dates

September 17-20, 2007

Conference Location

Florence, IT

Conference Title

SPIE Defense and Security Symposium

Pub Type

Conferences

Download Paper

Local Download

Keywords

aradiometer, calibration, night vision goggle, radiance, scale transfer, spectral responsivity, test-set

Citation

Eppeldauer, G. (2007), Uniform Calibration of Night Vision Goggles and Test Sets, SPIE Defense and Security Symposium | Europe | 2007 |, Florence, IT, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=841118 (Accessed April 19, 2024)