BOREAS Level-0 Daedalus TMS Imagery: Digital Counts in BIL Format Summary The level-0 Daedalus TMS imagery, along with the other remotely sensed images, was collected to provide spatially extensive information about radiant energy over the primary BOREAS study areas. This information includes detailed land cover and biophysical parameter maps such as FPAR and LAI. Two flights of the Daedalus TMS instrument were made onboard the ER-2 aircraft on September 16 and 17, 1994. Table of Contents * 1 Data Set Overview * 2 Investigator(s) * 3 Theory of Measurements * 4 Equipment * 5 Data Acquisition Methods * 6 Observations * 7 Data Description * 8 Data Organization * 9 Data Manipulations * 10 Errors * 11 Notes * 12 Application of the Data Set * 13 Future Modifications and Plans * 14 Software * 15 Data Access * 16 Output Products and Availability * 17 References * 18 Glossary of Terms * 19 List of Acronyms * 20 Document Information 1. Data Set Overview 1.1 Data Set Identification BOREAS Level-0 Daedalus TMS Imagery: Digital Counts in BIL Format 1.2 Data Set Introduction The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science effort covered those activities that were BOREAS community-level activities or required uniform data collection procedures across sites and time. These activities included the acquisition, processing, and archiving of 12-band Daedalus Thematic Mapper Simulator (Daedalus TMS) image data collected on the National Aeronautics and Space Administration's (NASA's) ER-2 aircraft. 1.3 Objective/Purpose For BOREAS, the Daedalus TMS imagery, along with the other remotely sensed images, was collected in order to provide spatially extensive information over the primary study areas. This information includes detailed land cover, biophysical parameter maps such as fraction of Photosynthetically Active Radiation (fPAR), and Leaf Area Index (LAI), and surface thermal properties. 1.4 Summary of Parameters Daedalus TMS level-0 image data in the BOREAS Information System (BORIS) contain the following parameters: Original housekeeping and calibration information and bands 1-12 in the NASA Ames Research Center (ARC) Band Interleaved by Line (BIL) format. 1.5 Discussion BORIS staff processed the Daedalus TMS level-0 images by: 1) Extracting pertinent header information from the level-0 image product and placing it in an American Standard Code for Information Interchange (ASCII) file on disk 2) Reading the information in the disk file and loading the online data base with needed information 1.6 Related Data Sets BOREAS Level-0 ER-2 Aerial Photography BOREAS Level-0 AOCI Imagery: Digital Counts in BIL Format BOREAS RSS-18 Level-1B AVIRIS Imagery: At-sensor Radiance in BIL Format 2. Investigator(s) 2.1 Investigator(s) Name and Title BOREAS Staff 2.2 Title of Investigation BOREAS Staff Science Aircraft Data Acquisition Program 2.3 Contact Information Contact 1 ------------------- Jeffrey S. Myers Aircraft Data and Sensor Facilities NASA Ames Research Center Moffett Field, CA (415) 604-6253 (415) 604-4987 (fax) jmyers@msmail.arc.nasa.gov Contact 2 ------------------- Jeffrey A. Newcomer NASA/GSFC Greenbelt, MD (301) 286-7858 (301) 286-0239 (fax) Jeffrey.Newcomer@gsfc.nasa.gov 3. Theory of Measurements The NASA Earth Resources Aircraft Program at Ames Research Center (ARC) operates the ER-2 aircraft to acquire data for Earth science research. The Daedalus TMS instrument used on the ER-2 aircraft collects radiance measurements in 10 spectral bands covering the visible and near-infrared spectrum from 0.436 to 1.054 micrometers (µm) and two thermal-infrared bands (one set in high gain and the other in low gain) covering 8.5 to 14.0 µm. Thematic considerations have dictated, within technical constraints, the choice of spectral band position and width in the Daedalus TMS sensor. Twelve bands were selected, eight of which correspond to Landsat Thematic Mapper (TM) bands. These bands were chosen after many years of analysis for their value in discrimination of several Earth surface features. A blue (0.45 to 0.52 µm) band provides increased penetration of water bodies as well as supporting analyses of land use, soil, and vegetation characteristics. The lower-wavelength cutoff is just below the peak transmittance of clear water, while the upper-wavelength cutoff is the limit of blue chlorophyll absorption for healthy green vegetation. Wavelengths below 0.45 µm are substantially influenced by atmospheric scattering and absorption. A green (0.52 to 0.60 µm) band spans the region between the blue and red chloro- phyll absorption bands and therefore corresponds to the green reflectance of healthy vegetation. A red (0.63 to 0.69 µm) band includes the chlorophyll absorption band of healthy green vegetation and represents one of the most important bands for vegetation discrimination. The latter is also useful for soil and geological boundary delineations. A reflective-infrared (0.76 to 0.90 µm) band is especially responsive to the amount of vegetation biomass present in a scene. It is useful for crop identification and emphasizes soil-crop and land- water contrasts. One mid-infrared (1.55 to 1.75 µm) band is sensitive to the turgidity or amount of water in plants. Such information is useful in crop drought studies and in plant vigor investigations. In addition, these are two of the few bands that can be used to discriminate between clouds, snow, and ice, which is very important in hydrologic research. The other mid-infrared band (2.08 to 2.35 µm) is important for the discrimination of geologic rock formations. It has been shown to be particularly effective in identifying zones of hydrothermal alteration in rocks. Finally, the thermal-infrared (8.5 to 14.0 µm) band that measures the amount of infrared radiant flux emitted from surfaces. The apparent temperature is a function of the emissivities and true or kinetic temperature of the surface. It is useful for locating geothermal activity, thermal inertia mapping for geologic investigations, vegetation classification, vegetation stress analysis, and soil moisture studies. 4. Equipment 4.1 Sensor/Instrument Description The Daedalus TMS-1268 scanner is designed to simulate spectral, spatial, and radiometric characteristics of the TM sensor on the Landsat-4 and -5 spacecraft. The Daedalus TMS is generally flown at high altitudes aboard NASA's ER-2 aircraft based at ARC and provides 25-m resolution at nadir at an altitude of 19,800-m (65,000 ft.). The Daedalus TMS sensor differs slightly from the Landsat TM instruments. Its 12 spectral channels are very similar to those of the TM sensor, but it has an additional infrared channel. The 12 spectral channels of the Daedalus TMS sensor have the following bandpasses: Daedalus TMS Channel Wavelength, µm ------------- -------------- 1 0.42 - 0.45 2 (TM1) 0.45 - 0.52 3 (TM2) 0.52 - 0.60 4 0.60 - 0.62 5 (TM3) 0.63 - 0.69 6 0.69 - 0.75 7 (TM4) 0.76 - 0.90 8 0.91 - 1.05 9 (TM5) 1.55 - 1.75 10 (TM7) 2.08 - 2.35 11 (TM6) (high gain) 8.5 - 14.0 12 (TM6) (low gain) 8.5 - 14.0 4.1.1 Collection Environment As part of the BOREAS Staff Science Data Collection Program, BORIS distributed 12-band level-0 Daedalus TMS image data. The Daedalus TMS was flown on NASA's ER- 2 aircraft during the BOREAS mission (see the BOREAS Experiment Plan for flight pattern details and objectives). Maintenance and operation of the instrument are the responsibility of ARC. The ER-2 Experimenter's Handbook (supplemental) produced by the High Altitude Missions Branch at ARC provides a description of the instrument, calibration procedures, and data format. 4.1.2 Source/Platform NASA's ER-2 Earth Resources Aircraft 4.1.3 Source/Platform Mission Objectives The original purpose of the Daedalus TMS was to provide high-altitude data in the visible, near-infrared, and thermal-infrared regions of the electromagnetic spectrum for use in land surface remote sensing and comparing with the Landsat Thematic Mapper instrument. 4.1.4 Key Variables Emitted radiation, reflected radiation, and temperature. 4.1.5 Principles of Operation None given. 4.1.6 Sensor/Instrument Measurement Geometry Instantaneous Field-Of-View (IFOV) 1.25 mrad Total Scan Angle 42.5 degrees Pixels/Scan Line 716 Sensor footprint is 25.0-m x 25.0-m at nadir at 19,800-m altitude. 4.1.7 Manufacturer of Sensor/Instrument Daedalus Enterprises Ann Arbor, Michigan 4.2 Calibration 4.2.1 Specifications The wavelength ranges (in µm) of the bands for the Daedalus TMS are: Daedalus TMS Channel Wavelength, µm ------------- -------------- 1 0.42 - 0.45 2 (TM1) 0.45 - 0.52 3 (TM2) 0.52 - 0.60 4 0.60 - 0.62 5 (TM3) 0.63 - 0.69 6 0.69 - 0.75 7 (TM4) 0.76 - 0.90 8 0.91 - 1.05 9 (TM5) 1.55 - 1.75 10 (TM7) 2.08 - 2.35 11 (TM6) (high gain) 8.5 - 14.0 12 (TM6) (low gain) 8.5 - 14.0 DESIGN DATA: IFOV 1.25 milliradians Across-track FOV +/- 21.25 degrees Inflight calibration Integrating sphere and two controllable blackbodies Short wavelength array temperature 255 K V/H range Variable 0.025 to 0.25 Scan rate Variable 10 to 100 scans/sec. Scan speed ability One-third of the IFOV, scan line to scan line Data quantization 8 bits (256 discrete levels) for all bands Number of video samples/scan line 716 Roll compensation +/-15 degrees Scan mirror 45-degree rotating mirror 4.2.1.1 Tolerance None given. 4.2.2 Frequency of Calibration The ARC Sensor Calibration Laboratory measures the Spectral Response Function (SRF) of each band several times per year using a full-aperture scanning monochromator. Radiometric calibration is regularly performed using a 30-in. integrating sphere with a 12-in. exit aperture. The sphere is calibrated periodically against a National Institute of Standards and Technology (NIST) standard reference source. The SRF is then convolved with the measured sphere radiance to produce in-band radiance for bands 1-10. The thermal IR bands (11 and 12) are calibrated with the two onboard blackbody reference sources that are viewed before and after each scan line during the data acquisition, together with the SRF measured in the laboratory. 4.2.3 Other Calibration Information Daedalus TMS data may be intentionally overscanned, e.g., operated at some integral multiple of the desired scan rate and then subsampled in preprocessing. The subsampling factor is reported as a "demagnification factor." 5. Data Acquisition Methods As part of the BOREAS Staff Science Data Collection Program, BORIS distributed 12-band level-0 Daedalus TMS image data. The Daedalus TMS was flown on NASA's ER- 2 aircraft during the BOREAS Mission (see the BOREAS Experiment Plan for flight pattern details and objectives). Maintenance and operation of the instrument are the responsibility of ARC. The ER-2 Experimenter's Handbook (supplemental) produced by the High Altitude Missions Branch at ARC provides a description of the instrument, calibration procedures, and data format. 6. Observations 6.1 Data Notes None given. 6.2 Field Notes None given. 7. Data Description 7.1 Spatial Characteristics The BOREAS Level-0 Daedalus TMS images cover the Northern Study Area (NSA) and Southern Study Area (SSA) which are located in the northeast and southwest portions of the overall BOREAS region. 7.1.1 Spatial Coverage The North American Datum 1983 (NAD83) corner coordinates of the SSA are: Latitude Longitude -------- --------- Northwest 54.321 N 106.228 W Northeast 54.225 N 104.237 W Southwest 53.515 N 106.321 W Southeast 53.420 N 104.368 W The NAD83 corner coordinates of the NSA are: Latitude Longitude -------- --------- Northwest 56.249 N 98.825 W Northeast 56.083 N 97.234 W Southwest 55.542 N 99.045 W Southeast 55.379 N 97.489 W 7.1.2 Spatial Coverage Map Not available. 7.1.3 Spatial Resolution The Daedalus TMS IFOV provides a footprint of 25.0-m at nadir at an altitude of 19,800-m which was typical of the BOREAS flight. 7.1.4 Projection The level-0 Daedalus TMS images were not placed in any sort of map or geographic coordinate projection. 7.1.5 Grid Description The BOREAS level-0 Daedalus TMS images are stored in their original data collection frame with increasing pixel sizes from nadir to the scanning extremes based on the scan angle. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage The level-0 Daedalus TMS image data were collected on September 16 and 17, 1994. 7.2.2 Temporal Coverage Map Study Area Dates ----- --------------------- SSA 16-Sep-1994 NSA 17-Sep-1994 7.2.3 Temporal Resolution Images were acquired only on September 16 and 17, 1994. 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (dtms0bil.def). 7.3.1 Parameter/Variable The parameter contained in the image data files is: Digital Number (DN) 7.3.2 Variable Description/Definition For the image data files: Digital Number (DN) - The quantized DN derived by the Daedalus TMS scanning system for the respective channel. 7.3.3 Unit of Measurement For the image data files: Digital Number (DN) - counts 7.3.4 Data Source The level-0 AOCI image bands were collected by the Daedalus TMS instrument on the ER2 aircraft. The raw data were decommutated, processed, and sent to BORIS by personnel within the High Altitude Aircraft Branch at NASA ARC. 7.3.5 Data Range The maximum range of DNs in each level-0 Daedalus TMS image band is limited from 0 to 255 8 bits and is stored in an 8 bit (byte) field. 7.4 Sample Data Record A sample data record for the level-0 Daedalus TMS images is not available here. Sample data format shown in the companion data definition file (dtms0bil.def). 8. Data Organization Although the image inventory is contained on the BOREAS CD-ROM set, the actual level-0 DTMS images are not. See section 15 for information about how to obtain the data. 8.1 Data Granularity The smallest unit of level-0 Daedalus TMS data is a single flight line of data. 8.2 Data Format(s) A level-0 Daedalus TMS tape contains one header file followed by up to 50 files containing data from Daedalus TMS flight lines. The header file contains one record of 9,192 bytes that contain a mixture of ASCII and binary values. The multibyte integer fields are stored as high-order byte first. The contents of the header record fields are: Bytes Description --------- ------------------------------------------------------------ 1 - 80 Data Description (ASCII characters, e.g., ‘TMS (BOREAS) Canada’) 81 - 90 Flight Number (ASCII characters, e.g., 94-143) 91 - 120 Data Collection Date (ASCII characters, e.g., 16 SEPTEMBER 1994) 121 - 150 Data Decommutation Date (ASCII characters) 151 - 180 Archive Tape Creation Date (ASCII characters) 181 - 182 Aircraft Number (binary 16-bit integer, value of 708) 183 - 184 Scanner Type (ASCII characters) 185 - 186 Reel Number (binary 16-bit integer) 187 - 188 Expected Number of Reels (binary 16-bit integer) 189 - 198 Filler bytes 199 - 200 Number of Channels Processed (binary 16-bit integer) 201 - 224 Channel Numbers (binary 16-bit integers) 225 - 236 Filler bytes 237 - 238 Mode used to specify flight line boundaries (ASCII characters) (AL = all data contained in one flight line) (SL = selected scan lines) (BOREAS tape) (GM = selected times) 239 - 240 Number of Operator-specified flight line intervals (binary 16-bit integer) 241 - 244 Start of flight line interval number 1 (binary 32-bit integer) 245 - 248 Start of flight line interval number 2 (binary 32-bit integer) . . 437 - 440 Start of flight line interval number 50 (binary 32-bit integer) 441 - 444 End of flight line interval number 1 (binary 32-bit integer) 445 - 448 End of flight line interval number 2 (binary 32-bit integer) . . 637 - 640 End of flight line interval number 50 (binary 32-bit integer) 641 - 9192 Filler bytes Each level-0 Daedalus TMS image from a given flight is contained in one tape file. A physical tape record of 9,192 bytes contains 12 logical records of 766 bytes that contain housekeeping information (50 bytes) and the image data (716 bytes) from the 12 Daedalus TMS spectral bands in BIL order. The bytes of the 16- bit and 32-bit values in the housekeeping information are ordered as high-order byte first. The detailed structure of each logical record is: Daedalus TMS Logical Data Record Structure Bytes 1 - 50 Housekeeping Information 1 - 2 Data Frame Status (16-bit integer) 0 implies the data are good; nonzero implies they are bad. 10 Interpolated data 20 Repeated data 30 Zero fill data 3 - 4 Run Number (16-bit integer) 5 - 8 Scan line count (32-bit integer) 9 - 12 Panel Thumbwheel switches (32-bit integer) Consists of 8 digits in the form YYFFFJJJ where YY is the last two digits of the year (e.g., 94) FFF is the flight number (e.g., 120) JJJ is the day of the year (e.g., 202) 13 - 14 Blackbody #1 Thermal Reference Temperature (16-bit integer) (hundredths of degrees C) 15 - 16 Blackbody #2 Thermal Reference Temperature (16-bit integer) (hundredths of degrees C) 17 - 18 Scan Speed (16-bit integer) (tenths of scans per second) 19 - 20 Greenwich Mean Time (GMT) hours (16-bit integer) 21 - 22 Minutes of the hour (16-bit integer) 23 - 24 Tenths of seconds (16-bit integer) 25 - 26 Demagnification value * 100 (16-bit integer) (Set to 100 to indicate unity, i.e., no demagnification) 27 - 28 Filler (16-bit integer) 29 - 30 Gain Value (times 1000) (16-bit integer) 31 - 32 Channel Number (16-bit integer) 33 - 36 Time (32-bit integer) (7 digits in the form of hhmmsst where hh is the hour, mm is the minutes, ss is the seconds, and t is the tenths of a second) 37 - 38 Blackbody #1 Response (16-bit integer) (Counts) (What the sensor sees when it looks at Blackbody #1) 39 - 40 Blackbody #2 Response (16-bit integer) (Counts) (What the sensor sees when it looks at Blackbody #2) 41 - 42 Aircraft Roll angle counts (16-bit integer) (0.03 degrees per count or 0.06 degrees per pixel) (Positive values indicate rotation of the aircraft in a clockwise direction when viewed from the front; negative values indicate counterclockwise rotation) 43 - 50 Filler bytes Bytes 51 - 766 Binary Image data 51 - 766 Digital counts for pixels 1 to 716 of the scan line (8-bit) The data inventory listing files contain numerical and character fields of varying length separated by commas. The character fields are enclosed with a single apostrophe marks. There are no spaces between the fields. Sample data records are shown in the companion data definition file (dtms0bil.def). 9. Data Manipulations 9.1 Formulae None. 9.1.1 Derivation Techniques and Algorithms None. 9.2 Data Processing Sequence 9.2.1 Processing Steps BORIS staff processed the level-0 Daedalus TMS imagery by: 1) Creating duplicate copies of the original image data tapes 2) Extracting information from the tape to ASCII files on disk 3) Using the extracted ASCII disk file information to inventory the images by date and location in the online data base 9.2.2 Processing Changes None. 9.3 Calculations 9.3.1 Special Corrections/Adjustments None given. 9.3.2 Calculated Variables None. 9.4 Graphs and Plots None. 10. Errors 10.1 Sources of Error None given. 10.2 Quality Assessment 10.2.1 Data Validation by Source Spectral errors could arise because of image-wide signal-to-noise ratio, saturation, cross-talk, spikes, or response normalization caused by a change in gain. 10.2.2 Confidence Level/Accuracy Judgment None given. 10.2.3 Measurement Error for Parameters None given. 10.2.4 Additional Quality Assessments None given. 10.2.5 Data Verification by Data Center BORIS staff reviewed the Daedalus TMS images through software that summarized the housekeeping information in the records of each flight line and histogrammed the image bands to gather minimum, maximum, mean, and standard deviation values that were then reviewed before loading the information into the data base. No anomalous values were noted. 11. Notes 11.1 Limitations of the Data Not available at this revision. 11.2 Known Problems with the Data To date, no discrepancies or problems have been noted in the data. 11.3 Usage Guidance Not available at this revision. 11.4 Other Relevant Information None given. 12. Application of the Data Set This data set can be used to supplement Landsat TM or other high resolution satellite images for land cover analyses. 13. Future Modifications and Plans None. 14. Software 14.1 Software Description BORIS staff developed software and command procedures for: 1) Extracting header information from level-0 Daedalus TMS images on tape and writing it to ASCII files on disk 2) Reading the ASCII disk file and logging the level-0 Daedalus TMS image products into the Oracle data base tables 14.2 Software Access The software is written in C and is operational on VAX 6410 and MicroVAX 3100 systems at Goddard Space Flight Center (GSFC). The primary dependencies in the software are the tape input/output (I/O) library and the Oracle data base utility routines. 15. Data Access 15.1 Contact Information Ms. Beth McCowan BOREAS Data Manager NASA/GSFC Greenbelt, MD (301) 286-4005 (301) 286-0239 (fax) beth@ltpmail.gsfc.nasa.gov 15.2 Data Center Identification See Section 15.1. 15.3 Procedures for Obtaining Data Users may place requests by telephone, electronic mail, or FAX. 15.4 Data Center Status/Plans The level-0 DTMS image data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The BOREAS contact at ORNL is: ORNL DAAC User Services Oak Ridge National Laboratory (865) 241-3952 ornldaac@ornl.gov ornl@eos.nasa.gov 16. Output Products and Availability 16.1 Tape Products The BOREAS level-0 Daedalus TMS data can be made available on 1600 or 6250 BPI 9- track, 8-mm, or DAT tapes. 16.2 Film Products None. 16.3 Other Products Although the image inventory is contained on the BOREAS CD-ROM set, the actual level-0 DTMS images are not. See section 15 for information about how to obtain the data. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation NASA. 1990. ER-2 Earth Resources Aircraft Experimenter's Handbook. National Aeronautics and Space Administration, Ames Research Center, Moffett Field, California. Airborne Instrumentation Research Project - Flight Summary Report Series. 1994. NASA Ames Research Center, Airborne Missions and Applications Division, Moffett Field, California. 94035. 17.2 Journal Articles and Study Reports Sellers, P., and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). Sellers, P., and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). Sellers, P., F. Hall, and K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96). Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. Cihlar, M. G. Ryan, B. Goodison, P. Crill, K. J. Ranson, D. Lettenmaier, and D. E. Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and early results from the 1994 field year. Bulletin of the American Meteorological Society. 76(9):1549-1577. Sellers, P., and F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue (in press). 17.3 Archive/DBMS Usage Documentation The collected data of BOREAS are currently archived at the NASA/GSFC. 18. Glossary of Terms None given. 19. List of Acronyms AOCI - Airborne Ocean Color Imager ARC - Ames Research Center ASCII - American Standard Code for Information Interchange BIL - Band Interleaved by Line BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information System BPI - Byte per inch CCT - Computer Compatible Tape CD-ROM - Compact Disk-Read-Only Memory DAAC - Distributed Active Archive Center DAT - Digital Archive Tape DN - Digital Number DTMS - Daedalus Thematic Mapper Simulator EOS - Earth Observing System EOSDIS - EOS Data and Information System fPAR - fraction of Photosynthetically Active Radiation GMT - Greenwich Mean Time GSFC - Goddard Space Flight Center IFOV - Instantaneous Field-of-View I/O - Input/Output LAI - Leaf Area Index NAD - North American Daturn 1983 NASA - National Aeronautics and Space Administration NIST - National Institute of Standards and Technology NSA - Northern Study Area ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park SRF - Spectral Response Function SSA - Southern Study Area TM - Thematic Mapper µm - micrometers URL - Uniform Resource Locator 20. Document Information 20.1 Document Revision Dates Written: 05-Nov-1996 Last Updated: 26-Feb-1998 20.2 Document Review Dates BORIS Review: 20-May-1997 Science Review: 20-May-1997 20.3 Document ID 20.4 Citation The BOREAS Level-0 Daedalus TMS data were collected and processed from the original aircraft tapes by personnel of the High Altitude Aircraft Branch at ARC. Their contributions to providing this data set are greatly appreciated. 20.5 Document Curator 20.6 Document URL Keywords ER-2 Daedalus TMS DTMS_L0.doc 04/17/98