Visible and near-infrared imaging spectrometer and its preliminary results from the Chang’E 3 project

Abstract

In order to conduct lunar surface mineral composition studies and content analysis, the Visible and Near-infrared Imaging Spectrometer (VNIS), one of the scientific payloads of the Chang'E 3 Yutu rover, has been developed to detect lunar surface objects and to obtain their reflectance spectra and geometric images. This is achieved with a 45° visual angle and at a height of 0.69 m. VNIS is equipped with a lunar surface calibration function, and the spectral range is 0.45-2.40 μm with a spectral resolution of 2-12 nm. It is capable of synchronously acquiring the full spectrum of lunar surface objects and in situ calibration. Here, we describe the VNIS and explain the preliminary results of the lunar surface exploration and calibration, which provides valuable information for scientific data processing and applications.

Verification of programmable, large-FOV spectral imaging technology based on a staring/scanning area-array detector

“…Therefore, we can calculate the parameters abcdefg by choosing four specific points (6) Finally, we use the eight parameters to perform a perspective transformation for the whole distortion image, which produces the corrected image. We then conduct image stitching to obtain a large-field-of-view image.…”

Near-infrared spectroscopy (NIRS) analysis of major components of milk and the development of analysis instrument

“…Depending on the choice of light-splitting mode, spectroscopic analysis instruments can be classified as grating-scanning, filter, Fourier, and array detection and acousto-optic tunable-filter spectroscopy. 6 For example, the IFS28/N Fourier NIRS, produced by BRUKER, which collects spectra in the 2 mm optical-path-length transmission regime, works under a wavelength ranging from 800 nm to 2500 nm; and the model 6500 NIR scanning spectrometer produced by FOSS use a digital-grating monochromator with Si (400-1100nm) and Pbs (1100-2500nm) detectors, whose scanning interval is 2 nm. 7…”

Visible and Near-Infrared Imaging Spectrometer (VNIS) For Chang E-3

“…In calibration status, the calibration unit will be aligned parallel to the mounting plane. When the VNIS is not operating, the calibration unit is enclosed within the framework to prevent spectrometer damage from lunar dust and other pollutants and also to provide thermal insulation 4 . The functional structure and three mode of the calibration unit are shown in Figure 3.…”

“…After soft landing on the Moon, Chang'E 3 has completed several aspects of the scientific exploration mission 1-3 , namely (1) a survey of the lunar surface topography and geological structure, (2) exploration of the lunar surface material composition and available resources, and (3) detection of the plasma layer of the Earth and Moon-based optical astronomical observations 4 . The Visible and Near-infrared Imaging Spectrometer (VNIS) is one of the main scientific payloads on Yutu.…”

“…The Visible and Near-infrared Imaging Spectrometer (VNIS) is one of the main scientific payloads on Yutu. It uses acousto-optic tunable filters (AOTFs) as the dispersive components and consists of a VIS/NIR imaging spectrometer (0.45-0.95 μm), a shortwave IR (SWIR) spectrometer (0.9-2.4 μm), and a calibration module with dust-proofing functionality [4][5] . The VNIS is mounted on the front of the rover Yutu to detect lunar surface objects with a 45 viewing angle and obtain the spectra and geometry data at a height of 0.69 m. The rover Yutu and the deployment of the VNIS are shown in Figure 1.…”