ASD技术指南第三版。
Analytical Spectral Devices, Inc. (ASD)
Technical Guide
3rd Ed.
Managing Editor: David C. Hatchell
Copyright?1999
Analytical Spectral Devices, Inc. 5335 Sterling Drive Suite A
Boulder, CO 80301-2344 USA
Phone: 303-444-6522 Fax: 303-444-6825 web: www.asdi.com email: info@asdi.com
'FieldSpec', 'LabSpec', 'SeaSpec', 'Driftlock' and 'Spectrode' are trademarks of Analytical Spectral Devices, Inc., Boulder, Colorado USA. Other brand and product names are trademarks of their respective holders.
The information and specifications contained in this guide are subject to change without notice. Analytical Spectral Devices, Inc. shall not be held liable for technical or editorial omissions or errors made herein; nor for incidental or consequential damages resulting from furnishing, performance or use of this material.
This document contains proprietary information protected by copyright.
Contact ASD for formal quotations.
Table of Contents
Welcome to the ASD Technical Guide ....................................................................................................................... 3 Company Profile ......................................................................................................................................................... 3 FieldSpec FR .............................................................................................................................................................. 4 FR Post Dispersive Spectrometer .............................................................................................................................. 4 FR Direct Path Fiberoptic Input .................................................................................................................................. 5 FR Speed and Sensitivity ........................................................................................................................................... 5 FR Longer Fiberoptic Cable Comparison ................................................................................................................... 7 FR Sampling Interval and Spectral Resolution ........................................................................................................... 8 FR Repeatability .......................................................................................................................................................12 FR Large Field-of-View .............................................................................................................................................15 FR Stray Light Rejection ...........................................................................................................................................15 Stray Light Look Alikes .............................................................................................................................................22 FR Driftlock ...............................................................................................................................................................22 FR Suggested Set-up ...............................................................................................................................................22 Artificial Illumination and Mineral Reflectance ..........................................................................................................26 FR Foreoptics ...........................................................................................................................................................31 FR Fiberoptic Cable ..................................................................................................................................................39 FieldSpec FR 1 deg Field-of-View Lens Foreoptic ...................................................................................................39 FR 1 Deg Field-of-View Mirror Foreoptic ..................................................................................................................40 FR 5 deg Field-of-View Lens Foreoptic ....................................................................................................................42 FR 8 deg Field-of-View Lens Foreoptic ....................................................................................................................42 FR 18 deg Field-of-View Tube ..................................................................................................................................43 FR PistolGrip ............................................................................................................................................................44 FieldSpec JR (350 -2500 nm) ...................................................................................................................................46 JR versus FR Plots ...................................................................................................................................................46 JR Unique Highlights ................................................................................................................................................50 FieldSpec NIR JR (1000 - 2500 nm) ........................................................................................................................51 FieldSpec UV/VNIR (350 -1050 nm) ........................................................................................................................51 VNIR Post Dispersive Spectrometer ........................................................................................................................51 VNIR Direct Path Fiberoptic Input ............................................................................................................................52 VNIR Fiberoptic Cable ..............................................................................................................................................52 VNIR Speed and Sensitivity .....................................................................................................................................52 VNIR Sampling Interval and Spectral Resolution .....................................................................................................53 VNIR Ground Truthing Hyperspectral Imagery ........................................................................................................55 VNIR Stray Light Rejection .......................................................................................................................................56 VNIR Driftlock ...........................................................................................................................................................58 VNIR Large Field-of-View .........................................................................................................................................58 VNIR Light Weight, Small, and Wear-able ...............................................................................................................58 VNIR Upgrade to Dual Spectrometer System ..........................................................................................................58 VNIR Upgrade to a FieldSpec FR ............................................................................................................................59 FieldSpec Dual UV/VNIR (350 -1050 nm) ................................................................................................................59 FieldSpec UV/VNIR/CCD .........................................................................................................................................59 FieldSpec HandHeld .................................................................................................................................................60 HandHeld Post Dispersive Spectrometer .................................................................................................................60 HandHeld Speed and Sensitivity ..............................................................................................................................61 HandHeld Sampling Interval and Spectral Resolution .............................................................................................62 HandHeld Small Size and Weight ............................................................................................................................64 HandHeld Large Field-of-View .................................................................................................................................64 HandHeld Stray Light Rejection ...............................................................................................................................65 HandHeld Driftlock ....................................................................................................................................................68 HandHeld Foreoptics ................................................................................................................................................69 LabSpec Pro Portable Spectrophotometer ...............................................................................................................70 LabSpec Pro Spectral Ranges .................................................................................................................................70
LabSpec Pro Features & Advantages: .....................................................................................................................70 Fundamentals of Spectroradiometry ........................................................................................... 错误！未定义书签。 Illumination Geometry ...............................................................................................................................................91 Wavenumber and Wavelength .................................................................................................................................98 Spectral Regions ......................................................................................................................................................99 Reflectance .............................................................................................................................................................101 Wavelength and Radiometric Calibration Methods ................................................................................................103 Blackbody Radiance and Spectroradiometric Calibration ......................................................................................108 The Benifits of Portable NIR Analysis ....................................................................................................................112 Making an NIR Analyzer Work For You..................................................................................................................114 Derivation of Bouguer-Lambert-Beer (BLB) Law ....................................................................................................116 Approximating Spot Size ........................................................................................................................................117 Foliar Spectral Features .........................................................................................................................................119 Vegetation Index Formulas .....................................................................................................................................120 Water Spectral Features .........................................................................................................................................120 Glossary ....................................................................................................................................... 错误！未定义书签。 Reprints ..................................................................................................................................................................128 Price List ...................................................................................................................................... 错误！未定义书签。
Welcome to the ASD Technical Guide
In this information age we are constantly bombarded by copious quantities of information, both wanted and unwanted, good and bad. Those of us in the business of creating information using the latest in technology are constantly answering requests for information, some simple, others complex and involved. We often end up answering the same questions again and again. In order to increase the efficiency of our work force and provide you with concise information, all wanted and good, we have put together a technical guide to ASD’s spectrophotometer/spectroradiometer product line along with a glossary of terms that are used in the light measurement field.
We welcome comments, criticisms and suggestions for the next issue, and we hope that our products will fill your application needs. The management and employees of ASD take pride in our customer service reputation. Our aim is to make sure that each customer understands how our instruments work and how to derive the most information from the data acquired. Please contact us by phone, fax, or email:
Phone: 303-444-6522 Fax: 303-444-6825 email: info@asdi.com web: www.asdi.com
Company Profile
Analytical Spectral Devices, Inc. (ASD) was founded in February, 1990. ASD manufactures and sells the FieldSpec, LabSpec, and SeaSpec lines of optical spectrometers (all trademarked by ASD). ASD's facilities occupy 11,000 square feet and include laboratories and equipment for the development, testing, calibration and manufacturing of high spectral resolution spectroradiometers, spectrophotometers, and associated run-time and data analysis software. This equipment includes: analog and digital oscilloscopes, function generators, power supplies, digital logic analyzers, optical benches and fixtures, fiber optic illuminators, monochromators, baffled tanks with optical windows for underwater calibrations, spectral line sources, and NIST traceable calibrated irradiance and radiance sources, computers, CAD software, and embedded software development tools. ASD currently employees a variety of Ph.D. Scientists, Engineers, Bachelors Degreed technicians.
FieldSpec FR
Several important features of the FieldSpec FR make it the best and unique choice for a field portable spectro -radiometer:
The FieldSpec FR is a post dispersive spectrometer. 高速色散分光光度计
The FieldSpec FR spectroradiometer uses a direct path fiber optic input. 辐射光度计使用的光纤直射输入路径
The FieldSpec FR spectroradiometer has an unbeatable combination of speed and sensitivity.
无可比拟的敏感度和传送速度的联合体
The FieldSpec FR spectroradiometer has the spectral resolution and sampling
interval required for ground truthing hyperspectral imagery. 高光谱图像的地面实况调查所需的光谱分辨率和采样间隔点
The FieldSpec FR spectroradiometer has excellent repeatability. 出类拔萃的重复性
The FieldSpec FR has the largest standard field-of-view of any portable spectroradiometer.
最大固定视野和便携光谱仪
The FieldSpec FR spectroradiometer has excellent stray light rejection. 出色的杂散光抑制
The FieldSpec FR spectroradiometer features the unique Driftlock? dark-drift correction system.
帧中继后向分散光谱仪
所有的ASD光谱仪是“后分散”。由于便携式光谱仪通常用于在受控的实验室环境以外，他们有机会接触到更高水平的环境光。在几乎所有情况下，这个环境光线偏离被测量到样品。这个环境的杂散光产生的错误是预谱仪大于他们的光谱仪，是分散后。
在预谱仪，样品单色光照明。光散关或通过样品传送，然后收集，并传送到仪器的探测器。环境光，还收集到被测量样品的偏离。因此，从仪器的单色照明和环境杂散光波长传送到探测器。因为环境杂散光信号可以代表一个总的光探测器测量信号的很大一部分，这是一个错误的主要来源。虽然这个源或错误，可以完全屏蔽环境光照的样品形式的所有来源的最小化，这往往排除了大部分的反射率和透过率光纤探针的使用。
在后谱仪，样品亮起白光。光散关或通过样品传送，然后分散并传送到仪器的光谱仪的狭缝。作为与前谱仪，环境光，还收集到被测量样品的偏离。所不同的是，后分散的仪器，唯一相同的波长，被探测器测环境杂散光被添加到从该仪器的样品照明所产生的信号。因此，环境杂散光信号代表了一小部分的总轻S ignal测量探测器。
FR直接路径光纤输入
FieldSpec FR光谱仪使用一个1米长的光纤输入，直接连接到光谱仪。这样的安排有两个好处。
首先，光纤输入，允许用户快速移动，而不必移动整个光谱仪非常轻巧的光纤探针从点对点。
其次，由于光纤光谱仪直接连接到有没有可拆卸接头，否则相关的信号损失（可拆卸接头通常会导致高达50％的信号损失）。
帧中继的速度和灵敏度
在FieldSpec FR光谱仪可以记录一个完整的350 - 2500 nm的谱，在0.1秒。这惊人的速度，可以在更短的时间内收集更多的数据，以及减少错误与云和太阳能照明下风的便利。
另一个要考虑的是，可以在指定的时间内收集扫描的数量。在FieldSpec FR也是唯一的便携式光谱仪控制计算机设计与独特的高速双向并行接口类型，允许连续的光谱序列的平均。串行接口（用于在一些竞争对手的工具），将严重限制可以平均每秒扫描的数量。
不过，速度并不是唯一的关键因素。结合速度快，具有极低的噪声等效辐射（NeDL）是什么使最佳的光谱仪。以下典型NeDL和信号噪声图显示了高超的FieldSpec FR光谱仪（注：每个光谱仪独特的NeDL）的灵敏度。