<title>Multiband Radiometer For Field Research</title>

Abstract

To develop the full potential of multispectral data acquired from satellites, increased knowledge and understanding of the spectral characteristics of specific earth features is required. Knowledge of the relationships between the spectral characteristics and important parameters of earth surface features can best be obtained by carefully controlled studies over areas, fields, or plots where complete data describing the condition of targets is attainable and where frequent, timely spectral measurements can be obtained. The currently available instrumentation systems are either inadequate or too costly to obtain these data. Additionally, there is a critical need for standardized acquisition and calibration procedures to ensure the validity and comparability of data.The radiometric instrument will be a multiband radiometer with 8 bands between 0.4 and 12.5 micrometers; the data acquisition system will record data from the multiband radiometer, a precision radiation thermometer, and ancillary sources. The radiometer and data handling systems will be adaptable to helicopter, truck, or tripod platforms. The system will also be suitable for portable hand -held operation. The general characteristics of the system are that it will be: (i) comparatively inexpensive to acquire, maintain, and operate; (ii)simple to operate and calibrate; (iii) complete with data handling hardware and software and (iv) well -documented for use by researchers.The instrument system will be a prototype of an economical system which can be utilized by many researchers to obtain large numbers of accurate, calibrated spectral measurements. As such it is a key element in improving and advancing the capability for field research in remote sensing.

Using spatial information technologies for detecting and mapping Eurasian watermilfoil

“…Reflectance measurements were made on 10 randomly selected plant canopies of each species or water surfaces with a Barnes modular multispectral radiometer (Robinson et al 1979). Measurements were made in the visible green (0.52-0.60 mm), visible red (0.63-0.69 mm), and near-infrared (NIR) (0.76-0.90 mm) spectral bands with a sensor that had a 158 field-of-view placed 1.0-1.5 m above each plant canopy or water surface.…”

Field Spectra and Airborne Digital Imagery for Detecting Phytophthora Foot Rot Infections in Citrus Trees

“…The measurements were acquired between 1100 and 1500 HR at the Alamo site, those at the La Feria site between 1200 and 1500 HR. Spectral measurements were acquired with a Barnes multispectral field radiometer (Barnes Engineering Co., Stamford, Conn.) having a sensor with a 15° field of view (Robinson et al, 1979). A 3.7-m stepladder was used to obtain nadir measurements 2 m above the apical area of the tree canopies (an area representative of what an airborne sensor would acquire), resulting in a viewing area of 0.22 m 2 .…”

The Agricultural Research Service’s Remote Sensing Program

“…Many of the group's scientists worked interactively with colleagues from NASA's Earth Sciences Branch and Purdue's Laboratory for Applications of Remote Sensing to determine how different sensors could be used to obtain information about plant growth and development. As part of this project, they acquired and helped design wideband radiometers and infrared radiation thermometers (Robinson et al, 1979;Tucker et al, 1981) and conducted workshops to teach others how to use them (Jackson et al, 1980). These scientists then started making observations in their field experiments, and began to develop remote sensing methods for assessing normal plant condition and providing early warning of plant stress (Wiegand et al, 1992).…”