Download - WHISPERS 会议报告
![Page 1: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/1.jpg)
刘瑶
![Page 2: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/2.jpg)
![Page 3: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/3.jpg)
![Page 4: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/4.jpg)
Introduction
Method
Experiment results
Summary & future work
![Page 5: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/5.jpg)
Definition of image simulation◦ generates synthetic images based
on the analysis and understanding of imaging acquisition
Application◦ Evaluation of system specifications◦ Test of processing facilities◦ Test-bench for future algorithm
development◦ Cost-versus-quality trade-offs
![Page 6: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/6.jpg)
Simulation tools◦ DIRSIG (The Digital Imaging and Remote Sensing
Image Generation Model)Spectral range: 0.3 - 20 μm regionTypes of imagery:multi- and hyper-spectral passive systems, polarimetric imagery, radiative transfer in littoral waters, and active LIDAR systems
source : http://dirsig.blogspot.com/2011/02/scene-building-with-blender.html
![Page 7: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/7.jpg)
Simulation tools◦ EeTes (EnMAP end-to-end Simulation)
Spectral range: VNIR & SWIR◦ PICASSO (Parameterized Image Chain Analysis & Simulation SOftware)
Spectral Range: visible to near-infrared(VISNIR) & TIR Summary
◦ Image simulation in mid-infrared regions is rarely discussed, especially the absorption bands.
![Page 8: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/8.jpg)
Applications of mid-infrared regions (3-5 μm)◦ Sensitive to high temperature
objects(fire, active volcanoes etc.) Mid-infrared absorption bands
◦ Fundamental research on these two special band to make preparation for mid-infrared simulation.
![Page 9: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/9.jpg)
Image simulation chain
◦ Surface scene simulation is basis for other two processes.
◦ Solar radiation is absorbed and less will reach the ground and be reflected.
Question◦ whether the reflected part of surface
radiance can be neglected ? ◦ what factors affect the surface radiance
composition ? study bands: 2.7 &4.3 μm
Surface scene simulation
Atmospheric simulation
Sensor hardware simulation
![Page 10: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/10.jpg)
ground radiance simualtion ◦ atmospheric transfer model MODTRAN (MODerate resolution atmospheric TRANsmission)◦ MODTRAN can simulate the absorption effects of atmospheric molecules to the solar radiation.
Simulation outcome◦ Total surface radiance (represented by Rt)
Reflected radiance ( represented by Rr) Emitted radiance (represented by Re) Rt = Rr +Re
◦ Evaluation index: Rr / Re
![Page 11: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/11.jpg)
Input parameters
atmosphere typemid latitude
summer/winteraerosol type urban
visibility 50 kilometerssolar zenith angle 30°view zenith angle 30°
relative azimuth angle 90°surface temperature 300K/272.2K
gas concentration(H2O,O3,CO2)
default values
sensor altitude 1msurface altitude 0
![Page 12: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/12.jpg)
surface features
assume all features are lambert in simulation.
Type of objects Name
vegetationconifer
deciduousgrass
soilsandy loam
brown fine sandy loambrown loamy fine sand
watersea water
distilled water
![Page 13: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/13.jpg)
Spectral reflectance(from JHU spectral library)
The reflectance of soil is relatively higher than vegetation and water
![Page 14: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/14.jpg)
Rr/Re near 2.7μm in summer and winter
Temperature & reflectance have impacts on surface radiance compositon in mid-infrared absorption bands
![Page 15: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/15.jpg)
Rr/Re near 4.3μm in summer and winter
The result is similar to that in 2.7 μm regions
![Page 16: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/16.jpg)
Ratio of Rr to Re of the band◦ assumption: square-wave spectral response
function Response equals 1 within the band Response equals 0 outside the band
Initial wavelength Final wavelength
0
1
wavelength
r e s p o n s e
![Page 17: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/17.jpg)
Rr_b/Re_b in 2.7 & 4.3 band
The result in bands is consistent with that in wavelengths.
![Page 18: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/18.jpg)
Summary◦ Temperature and reflectance of surface
features both contribute to the surface radiance composition.
◦ Whether the reflected radiance can be neglected in surface scene simulation relates to the expected accuracy of simulation. For example, if a 10 percent of error is allowed, the reflection of soils, water and vegetation can all be neglected.
![Page 19: WHISPERS 会议报告](https://reader033.vdocuments.net/reader033/viewer/2022061316/5681348c550346895d9b7394/html5/thumbnails/19.jpg)
Further work◦ More factors need to be involved: water vapor
contents, BRDF, etc.◦ Reflectance data of surface features should be
expanded.◦ In-situ validation: field measurements of
reflected and emitted radiance. ◦ Simulation is working with the sensor. Since
the proportion changes with the wavelength, for specific sensor, the surface composition analysis also depends on the bandwidth.