Itt Manufacturing Enterprises, Inc.

Exelis Inc.

David Stanley Smith

Douglas Lent Cohen

Ronald Joseph Glumb

Sheldon David Stokes

David R Wickholm

Kimberly Ann Slack

Glen Daniel White

A calibration device for a radiometer includes an integrating cavity and a honeycomb blackbody mounted to the integrating cavity. A plurality of emitters are mounted to the exterior rim of the integrating cavity for transmitting narrow band wavelengths of light into and out of the integrating cavity. A controller, selectively, activates one or more emitters to radiate a single narrow band wavelength of light during an ON period and turn OFF during another period. A plurality of reference detectors are also mounted to the exterior rim of the integrating cavity for measuring the intensity of each narrow band radiation outputted from the integrating cavity. The reference detectors are effective in determining changes in intensity output by each of the narrow band emitters from the integrating cavity. The measured changes in intensity outputted by the emitters are used to calibrate the radiometer with the changes traced back to a NIST standard.

Onboard calibration source for spectral calibraton of a radiometer

A device for calibrating a sensor using solar radiation includes a sensor configured to measure electromagnetic radiation received through a field of view (FOV) having a normal line of sight and at least two baffles removably insertable across the FOV of the sensor and inclined to the line of sight. Each baffle has first and second opposing surfaces, with the first surface disposed to face the solar radiation and the second surface disposed to face the sensor. One of the first or second surface is configured as a diffused surface, and the other of the first or second surface is configured as a specular surface.

Use of solar illumination and baffles to calibrate visible sensors

A solar calibration device for a remote sensor having a housing having a deployable door at one portion of the housing and an aperture at another portion of the housing is provided. Disposed in the housing is a solar diffuser for receiving solar irradiance when the deployable door is in an open position, and diffusely reflecting the received solar irradiance. A solar diffuser monitor also disposed within the housing receives diffusely reflected solar irradiance from the solar diffuser, for calibrating the solar irradiance reflected from the solar diffuser, and receives solar irradiance directly from the sun through the aperture to calibrate the spectral reflectance of the solar diffuser monitor detectors based on the solar irradiance received directly from the sun.

Solar calibration device and method

Methods and apparatus are described for assessing the reflective properties of mirrors at different angles of incidence without precise knowledge of the mirror's basic optical constants and/or without precise knowledge of the mirror's over-coating prescription. Reflectance values can be accurately calculated for multiple angles of incidence based upon measurement data collected for a single angle of incidence. The approach uses equations based on the Fresnel equations for reflectance in which reflectance is calculated as a function of the angle of incidence of incoming light to the scanned mirror used to collect the signal. The angle of incidence-based approach allows accurate reflectance values to be calculated over a broad range of wavelengths and angle of incidences without detailed knowledge of the optical properties of the coating material and the substrate underneath. The described methods and apparatus are particularly useful for calibrating measurements made with remote sensing instruments that use scanned mirrors.

Growing community of inventors

Fort Wayne, IN, United States of America

David Stanley Smith