The Visible-Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (S-NPP) spacecraft as a primary sensor was launched October 28, 2011. There are 22 VIIRS bands: 7 thermal emissive bands (TEBs), 14 reflective solar bands (RSBs) and a Day Night Band (DNB). An on-orbit On-Board Calibrator BlackBody (OBCBB) is used as the TEB calibration source that tracks the detector gain change on a scan-by-scan basis. A thermal model to account for internal sensor emission is used in both the OBCBB derived gain calibration and Earth View (EV) radiance and brightness temperature retrievals. This thermal model uses pre-launch calibration coefficients to convert detector response into radiance and internal VIIRS cavity thermistors to estimate the sensor's internal emission from various optical surfaces. The inputs to the thermal model have uncertainties which introduce errors in both the gain correction and the EV retrievals. This paper will discuss the impacts of the thermal model uncertainties on the VIIRS calibration.

The Visible Infrared Imager Radiometer Suite (VIIRS) Reflective Solar Band Automated Calibration (RSBAutoCal) Day Night Band (DNB) dark signal and gain ratio calculations exhibit two issues: gain ratio trending instability and gain ratio differences relative to those calculated using the VIIRS Recommended Operating Procedures (VROP) monthly look-up table (LUT) generation tool. These issues have thus far prevented transition of RSBAutoCal to automated mode for these two DNB calibration parameters. In this paper we describe the successful diagnosis of the gain ratio stability issue. We also present a solution to stabilize the gain ratios, thereby clearing the way for their tuning to match the VROP derived gain ratios and transition of RSBAutoCal to automated mode for both dark signals and gain ratios. This solution has been fully and successfully tested with Matlab code developed to simulate RSBAutoCal gain ratio and dark signal calculations and is ready for delivery for operational implementation.

The Suomi National Polar-orbiting Partnership (SNPP) spacecraft's primary sensor is the Visible-Infrared Imaging Radiometer Suite (VIIRS) which launched on October 28, 2011. It has 22 total bands with 7 thermal emissive bands (TEBs), a high dynamic range monochromatic Day Night Band (DNB) and 14 reflective solar bands (RSBs). The TEB gain and noise performance is tracked on-orbit using an On-Board Calibrator BlackBody (OBCBB) as a thermal source. The TEBs view the OBCBB every scan allowing gain correction roughly every 1.7 seconds. Long term trending of the F factor (inversely proportional to gain) and Noise Equivalent delta Temperature (NEdT) allows the stability and uncertainty in the TEB thermal model to be evaluated. This paper will discuss the impacts of the thermal model uncertainties on the VIIRS calibration and how those impact the long term performance of VIIRS. It will also show the stability of the TEBs over 3 years on-orbit.

The Visible Infrared Radiometer Suite (VIIRS) sensor data record (SDR) product contains geolocated and calibrated radiances, quality flags, and derived products such as brightness temperature and reflectance. The active fire team reported an inconsistency in the way radiance limits and derived products limits are generated. The quality flags are also independently determined for radiance limits and derived product limits. This paper focuses on operational code modifications to address the inconsistent radiance and derived products and quality flag determination algorithm.

The Visible-Infrared Imaging Radiometer Suite (VIIRS) on-board the Suomi National Polar-orbiting Partnership (SNPP) spacecraft as a primary sensor was launched October 28, 2011. It has 22 bands: 7 thermal emissive bands (TEBs), 14 reflective solar bands (RSBs) and a Day Night Band (DNB). The TEBs are calibrated on-orbit using the On-Board Calibrator BlackBody (OBCBB) as a thermal source every scan to track the detector gain change. A thermal model is used in both the OBCBB derived gain calibration as well as in other corrections to the Earth View (EV) radiance and brightness temperature retrievals. This thermal model uses prelaunch calibration coefficients to convert detector response into radiance as well as VIIRS cavity thermistors to estimate the sensor's internal emission contributions. The inputs to the thermal model have uncertainties which introduce errors in both the gain correction and the EV retrievals. This paper will discuss the impacts of the thermal model uncertainties on the VIIRS calibration.

In this paper, we quantify several spatial capabilities of the human tactile system needed for tactile feedback, or teletaction. Psychophysics experiments measure the amplitude resolution of the human tactile system, the effects of shear stress on grating orientation discrimination, and the effects of viscoelasticity (creep and relaxation) on tactile perception for static touch. The results are used to determine teletaction system design parameters. We find that 10% amplitude resolution is sufficient for a teletaction system with a 2 mm elastic layer and 2 mm tactor spacing.

A teletaction system uses a tactile display to present the user with information about texture, local shape, and/or local compliance. Current tactile displays are flat and rigid, and require precise machining and assembly of many parts. This paper describes the fabrication and performance of a one-piece pneumatically-actuated tactile display molded from silicone rubber. Tactor spacing is 2.5 mm with 1 mm diameter tactor elements. Tactile display compliance ensures contact between the finger and tactile display at all times. Unlike previous pneumatic tactile displays, there is no chamber leakage and no seal friction. A psychophysics experiment showed that a synthetic grating on the tactile display was perceived as well as a low-pass-filtered real contact.

Teletaction is the transmission of cutaneous information from a remote tactile sensor to an operator's skin, typically the finger tips. Ideally, one would like a realistic sensation of directly touching an object with one's own finger and sense properties such as local shape, hardness, or texture. Teletaction or tactile feedback is one component of haptic feedback, the other component being force or kinesthetic feedback. This paper considers design issues for teletaction systems, particularly sampling density, aliasing, and the limitations of using an array of 1-DOF actuators to approximate a continuous stress distribution on the human finger.