Langley DAAC Version Number: LD_008_015_006_00_00_0_19990609 MAPS Readme 1.0 Introduction This file contains information about the Measurement of Air Pollution from Satellites (MAPS) sample read software and data files. The table below lists for all of the data sets available through the Langley DAAC, the format of the data sets and if sample read software is also available. The data sets appear in the order as they became available to the user community. These are the data sets that are available through the Langley DAAC: This table lists all data sets available through the Langley DAAC as well availability of sample read software. Data Set Name Sample Read Software Availability Data Format ------------- --------------------------------- ----------- MAPS_OSTA3_CO5X5_HDF Yes HDF MAPS_SRL1_CO5X5_HDF Yes HDF MAPS_SRL2_CO5X5_HDF Yes HDF MAPS_OSTA3_COSEC_HDF Yes HDF MAPS_SRL1_COSEC_HDF Yes HDF MAPS_SRL2_COSEC_HDF Yes HDF MAPS_OSTA3_LVL1_HDF Yes HDF MAPS_SRL1_LVL1_HDF Yes HDF MAPS_SRL2_LVL1_HDF Yes HDF This "readme" file includes the following five other sections: Section 2.0 - describes all sample C programs (source files). Section 3.0 - discusses how to create the executables from the C programs. Section 4.0 - demonstrates how to invoke the run-time executables. Section 5.0 - provides general information on the data sets. Section 6.0 - provides more detailed implementation notes. If users have questions while using the MAPS sample read software, please contact the Langley User and Data Services office. EOSDIS Langley DAAC User and Data Services Office NASA Langley Research Center Mail Code 157D Hampton, Virginia 23681-2199 U.S.A. E-mail: support-asdc@earthdata.nasa.gov Phone: (757)864-8656 FAX: (757)864-8807 2.0 Read Software Files Currently, there is one sample read program for the MAPS data sets. This code is written in the C language. This C program has been tested on the Sun,SGI, Dec Alpha, and HP UNIX-based workstations. All library functions in the C source codes are tested for ANSI C conformance. C shell scripts are included for the convenience of creating the executable files from the C source files. These files and their purposes are listed as follows: compile_read_maps_co5x5 - contains a set of commands to build the run-time executable for the 5 by 5 grid box data sets. maps_co5x5_read.c - reads the MAPS Carbon Monoxide 5 by 5 degree grid boxes formatted files that were written using the HDF extensions. This code is written in the C language. compile_read_maps_cosec - contains a set of commands to build the run-time executable for the second by second point data data sets. maps_cosec_read.c - reads the MAPS Carbon Monoxide second by second point data files that were written using the HDF extensions. This code is written in the C language. compile_read_maps_lvl1 - contains a set of commands to build the run-time executable for the level 1 data data sets. maps_lvl1_read.c - reads the MAPS level 1 data files that were written using the HDF extensions. This code is written in the C language. 3.0 Creating C Executable Files The following sections describe how to create the executables for the HDF. 3.1 Creating the Executables for the HDF data format files The user has two methods of building the sample read programs from the source files. The user is able to build the code from the command line or for conveince, build the code using the C shell script that was provided with the sample read software. All files are defined in Section 2.0. Users working with the HDF data format files need the HDF libraries in order to build the executable for the sample read software. HDF information, documentation, tutorials, libraries, etc. can be found on-line at the URL: http://hdf.ncsa.uiuc.edu A utility (hdp) is provided in the HDF libraries which will extract information about the contents of the HDF file. The commands: hdp -H hdp dumpsds [-options] hdp dumpvd [-options] vshow [+|+vdata_id] These will give information as to the size, type, and names of the HDF data structures. The [-H] option will give help information. Download the HDF libraries from the NCSA web site ( http://hdf.ncsa.uiuc.edu ). This code uses Version HDF4.1r2. Other versions of the HDF libraries may not work with this code. NCSA uses the gnu gzip compression utility for some packages. If you do not already have this software which is needed to uncompress the file, you can obtain it from one of the Gnu mirror sites listed at http://www.gnu.org/order/ftp.html Once all of the HDF libraries are located on your system, you are now ready to compile the sample read software. Currently, the Langley DAAC is working with Versions 4.1r1 and 4.1r2 of the HDF library. 3.1.1 Create an executable using the C shell scripts The files that contain the C shell scripts are those files that begin with the word "compile" in the file name. To build the executable that reads the HDF data format files for the MAPS, you must obtain the compile script which is for your particular data set. The scripts are called compile_read_maps_co5x5, compile_read_maps_cosec, and compile_read_maps_lvl1. Refer to (edit) the sample script 'compile_read_maps_co5x5' to link the HDF libraries and compile the C program. Check the permissions on this file to make sure execute permission is set for the owner: ls -l compile_read_maps_co5x5 ls -l compile_read_maps_cosec ls -l compile_read_maps_lvl1 should display something like -rwxr--r-- 1 OWNER GROUP 4077 Feb 3 00:44 compile_read_maps_co5x5 -rwxr--r-- 1 OWNER GROUP 4077 Feb 3 00:44 compile_read_maps_cosec -rwxr--r-- 1 OWNER GROUP 4064 Feb 3 00:44 compile_read_maps_lvl1 where OWNER and GROUP are the file owner and group information. The owner executable permission is the x in -rwxr--r--. To set proper permissions (assuming you are the file owner), type chmod 744 compile_read_maps_co5x5 Execute the script 'compile_read_maps_co5x5' to create the executable by typing source compile_read_maps_co5x5 or, on some systems you need only type compile_read_maps_co5x5 compile_read_maps_cosec compile_read_maps_lvl1 To run the executable at the command line, just type: read_maps_co5x5 read_maps_cosec read_maps_lvl1 **NOTE: Please refer to the compile script that applies to the data set that you would like to read. Data Set Name Compile Script Name ------------- ------------------- MAPS_OSTA3_CO5X5_HDF compile_read_maps_co5x5 MAPS_SRL1_CO5X5_HDF compile_read_maps_co5x5 MAPS_SRL2_CO5X5_HDF compile_read_maps_co5x5 MAPS_OSTA3_COSEC_HDF compile_read_maps_cosec MAPS_SRL1_COSEC_HDF compile_read_maps_cosec MAPS_SRL2_COSEC_HDF compile_read_maps_cosec MAPS_OSTA3_LVL1_HDF compile_read_maps_lvl1 MAPS_SRL1_LVL1_HDF compile_read_maps_lvl1 MAPS_SRL2_LVL1_HDF compile_read_maps_lvl1 3.1.3 Create with the compiler This method uses the combinations of the HDF libraries, the HDF includes files, and the programs provided for the data sets (maps_co5x5_read.c). To build the executable for these data sets, at the command line prompt type: On your Sun system, the following command was used to build the sample software: gcc -o read_maps_co5x5 maps_co5x5_read.c -I/usr/local/hdf/include \ -L/usr/local/hdf/lib -lmfhdf -ldf -ljpeg -lz -L/usr/lib NOTE: You will have to modify the paths for the HDF libraries to the correct location on your system. On your SGI Irix 6.2 system, the following command was used to build the sample software: cc -ansi -n32 -mips3 -O -s -o read_maps_co5x5 maps_co5x5_read.c \ -I/usr/people2/paula/HDF/4.1r2_irix6.2/include \ -L/usr/people2/paula/HDF/4.1r2_irix6.2/lib -ldf -lz NOTE: You will have to modify the paths for the HDF libraries to the correct location on your system. On your Dec Alpha V4.0A system, the following command was used to build the sample software: cc -o read_maps_co5x5 maps_co5x5_read.c -I/usr/local/HDF4.1r1/include \ -L/usr/local/HDF4.1r1/lib -lmfhdf -ldf -ljpeg -lz -L/usr/lib NOTE: You will have to modify the paths for the HDF libraries to the correct location on your system. On your HP system, the following command was used to build the sample software: gcc -o read_maps_co5x5 maps_co5x5_read.c -I/usr/local/HDF4.1r1/include \ -L/usr/local/HDF4.1r1/lib -lmfhdf -ldf -ljpeg -lz -L/usr/lib NOTE: You will have to modify the paths for the HDF libraries to the correct location on your system. Remember that your paths on your system may be different than these listed above. Please modify your paths accordingly. 4.0 Invoking Read Software This section illustrates the invocation of the executable files. Section 4.1 describes how to run the read program for the Carbon Monoxide 5 by 5 grid boxes data sets (MAPS_OSTA3_CO5X5_HDF, MAPS_SRL1_CO5X5_HDF, and MAPS_SRL2_CO5X5_HDF). Section 4.2 describes how to run the read program for the Carbon Monoxide second by second data sets (MAPS_OSTA3_COSEC_HDF, MAPS_SRL1_COSEC_HDF, and MAPS_SRL2_COSEC_HDF). Section 4.3 describes how to run the read program for the level 1 data sets (MAPS_OSTA3_LVL1_HDF, MAPS_SRL1_LVL1_HDF, and MAPS_SRL2_LVL1_HDF). 4.1 Running the Read Program for the Carbon Monoxide 5 by 5 grid boxes Data Sets Currently, the executable maps_co5x5_read.c read program (C version) for the MAPS_OSTA3_CO5X5_HDF, MAPS_SRL1_CO5X5_HDF, MAPS_SRL2_CO5X5_HDF data sets do not accept command line arguments. When this program is executed, it requests an input filename. The output file name is automatically created by appending ".rpt" to the input file name. This code assumes that the data and code are located in the same area. The report file generated will also be included in the local working area. After entering the file name, the user is presented with a parameter selection list. At this point, the program generates the report file and exits. The following line will begin program execution: % read_maps_co5x5 A sample of the interactive program execution is provided in Section 6.0. 4.2 Running the Read Program for the Carbon Monoxide Second by Second Data Sets Currently, the executable maps_cosec_read.c read program (C version) for the MAPS_OSTA3_COSEC_HDF, MAPS_SRL1_COSEC_HDF, MAPS_SRL2_COSEC_HDF data sets do not accept command line arguments. When this program is executed, it requests an input filename. The output file name is automatically created by appending ".rpt" to the input file name. This code assumes that the data and code are located in the same area. The report file generated will also be included in the local working area. After entering the file name, the user is presented with a parameter selection list. At this point, the program generates the report file and exits. The following line will begin program execution: % read_maps_cosec A sample of the interactive program execution is provided in Section 6.0. 4.3 Running the Read Program for the Level 1 Data Sets Currently, the executable maps_cosec_read.c read program (C version) for the MAPS_OSTA3_LVL1_HDF, MAPS_SRL1_LVL1_HDF, MAPS_SRL2_LVL1_HDF data sets do not accept command line arguments. When this program is executed, it requests an input filename. The output file name is automatically created by appending ".rpt" to the input file name. This code assumes that the data and code are located in the same area. The report file generated will also be included in the local working area. After entering the file name, the user is presented with a parameter selection list. At this point, the program generates the report file and exits. The following line will begin program execution: % read_maps_lvl1 A sample of the interactive program execution is provided in Section 6.0. 5.0 Data Sets Information The following subsections provide information the MAPS data sets on-line at the Langley DAAC. DATA SET NAME SECTION ------------- ------- MAPS_OSTA3_CO5X5_HDF 5.1 MAPS_SRL1_CO5X5_HDF 5.2 MAPS_SRL2_CO5X5_HDF 5.3 MAPS_OSTA3_COSEC_HDF 5.4 MAPS_SRL1_COSEC_HDF 5.5 MAPS_SRL2_COSEC_HDF 5.6 MAPS_OSTA3_COSEC_HDF 5.7 MAPS_SRL1_COSEC_HDF 5.8 MAPS_SRL2_COSEC_HDF 5.9 Each set of data set's information was obtained from the data files, documents, or directly from the data producer/provider. The high-level data set descriptions, the data files, the variables in the data files, and the contacts for data production are given under each data set. Some data sets contain the data producer's/provider's responses to questions on the data contents. These questions and/or responses are collected under the "NOTES ON DATA" section. 5.1 MAPS_OSTA3_CO5X5_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Office of Space and Terrestrial Applications - 3 (OSTA3) Carbon Monoxide 5 degree by 5 degree data in Hierarchical Data Format (HDF) (MAPS_OSTA3_CO5X5_HDF) FILE NAMING CONVENTION: MAPS_OSTA3_CO5X5_HDF data set files are prefixed with "osta35x5" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the end day the data were collected for a particular granule. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 5 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Longitude Degrees Latitude Degrees CO Parts Per Billion by Volume N2O Parts Per Billion by Volume Counts Number Points per Average NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. Data are not available for dates October 8 - 9, 1984. There were temperature problems with the platform and therefore MAPS did not collect data for those two days. Grids are referenced on 5 degree boxes starting in the lower left corner. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Sample data from the osta35x5_1006_06_hdf file: This is from the report file for the osta35x5_1006_06_hdf file. *************************** LONGITUDE NO. 1 ****************************** Longitude: -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 Latitude: 65.00 60.00 55.00 50.00 45.00 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 -5.00 -10.00 -15.00 -20.00 -25.00 -30.00 -35.00 -40.00 -45.00 -50.00 -55.00 -60.00 -65.00 -70.00 CO: -777.77 0.00 121.05 0.00 71.21 68.13 72.57 0.00 54.02 55.55 0.00 0.00 56.34 57.91 0.00 0.00 76.01 91.99 0.00 121.01 98.30 79.49 92.62 0.00 0.00 80.63 -777.77 -777.77 N2O: -777.77 0.00 365.12 0.00 273.06 248.65 305.36 0.00 237.67 239.36 0.00 0.00 280.62 285.19 0.00 0.00 306.34 346.99 0.00 338.80 296.31 243.36 298.29 0.00 0.00 362.43 -777.77 -777.77 Counts: -777.77 0.00 5.00 0.00 55.00 15.00 3.00 0.00 7.00 13.00 0.00 0.00 17.00 60.00 0.00 0.00 41.00 22.00 0.00 7.00 62.00 7.00 34.00 0.00 0.00 18.00 -777.77 -777.77 INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 5.2 MAPS_SRL1_CO5X5_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Space Radar Laboratory - 1 (SRL1) Carbon Monoxide 5 degree by 5 degree data in Hierarchical Data Format (HDF) (MAPS_SRL1_CO5X5_HDF) FILE NAMING CONVENTION: MAPS_SRL1_CO5X5_HDF data set files are prefixed with "srl15x5" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the end day the data were collected for a particular granule. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 5 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Longitude Degrees Latitude Degrees CO Parts Per Billion by Volume N2O Parts Per Billion by Volume Counts Number Points per Average NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. Grids are referenced on 5 degree boxes starting in the lower left corner. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Sample data from the srl15x5_0409_09_hdf file: This is from the report file for the srl15x5_0409_09_hdf file. *************************** LONGITUDE NO. 1 ****************************** Longitude: -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 Latitude: 65.00 60.00 55.00 50.00 45.00 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 -5.00 -10.00 -15.00 -20.00 -25.00 -30.00 -35.00 -40.00 -45.00 -50.00 -55.00 -60.00 -65.00 -70.00 CO: -777.77 0.00 95.37 92.63 93.51 99.57 0.00 125.65 0.00 0.00 0.00 0.00 0.00 57.35 68.50 0.00 0.00 106.21 105.84 0.00 125.89 83.71 90.69 82.26 88.80 77.19 -777.77 -777.77 N2O: -777.77 0.00 311.54 317.94 309.87 310.93 0.00 351.55 0.00 0.00 0.00 0.00 0.00 248.63 282.03 0.00 0.00 317.88 332.78 0.00 333.67 303.63 308.20 300.40 307.73 323.04 -777.77 -777.77 Counts: -777.77 0.00 134.00 68.00 41.00 9.00 0.00 8.00 0.00 0.00 0.00 0.00 0.00 36.00 21.00 0.00 0.00 57.00 5.00 0.00 11.00 88.00 69.00 39.00 69.00 10.00 -777.77 -777.77 INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 5.3 MAPS_SRL2_CO5X5_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Space Radar Laboratory - 2 Carbon Monoxide 5 degree by 5 degree data in Hierarchical Data Format (HDF) (MAPS_SRL2_CO5X5_HDF) FILE NAMING CONVENTION: MAPS_SRL2_CO5X5_HDF data set files are prefixed with "srl25x5" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the end day the data were collected for a particular granule. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 5 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Longitude Degrees Latitude Degrees CO Parts Per Billion by Volume N2O Parts Per Billion by Volume Counts Number Points per Average NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. Grids are referenced on 5 degree boxes starting in the lower left corner. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Sample data from the srl25x5_0930_03_hdf file: This is from the report file for the srl25x5_0930_03_hdf file. *************************** LONGITUDE NO. 1 ****************************** Longitude: -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 -180.00 Latitude: 65.00 60.00 55.00 50.00 45.00 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 -5.00 -10.00 -15.00 -20.00 -25.00 -30.00 -35.00 -40.00 -45.00 -50.00 -55.00 -60.00 -65.00 -70.00 CO: -777.77 0.00 95.37 92.63 93.51 99.57 0.00 125.65 0.00 0.00 0.00 0.00 0.00 57.35 68.50 0.00 0.00 106.21 105.84 0.00 125.89 83.71 90.69 82.26 88.80 77.19 -777.77 -777.77 N2O: -777.77 0.00 311.54 317.94 309.87 310.93 0.00 351.55 0.00 0.00 0.00 0.00 0.00 248.63 282.03 0.00 0.00 317.88 332.78 0.00 333.67 303.63 308.20 300.40 307.73 323.04 -777.77 -777.77 Counts: -777.77 0.00 134.00 68.00 41.00 9.00 0.00 8.00 0.00 0.00 0.00 0.00 0.00 36.00 21.00 0.00 0.00 57.00 5.00 0.00 11.00 88.00 69.00 39.00 69.00 10.00 -777.77 -777.77 INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 5.4 MAPS_OSTA3_COSEC_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Office of Space and Terrestrial Applications - 3 (OSTA3) Carbon Monoxide Second by Second data in Hierarchical Data Format (HDF) (MAPS_OSTA3_COSEC_HDF) FILE NAMING CONVENTION: MAPS_OSTA3_COSEC_HDF data set files are prefixed with "osta3lv2" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the beginning hour of the day the data were collected for a particular granule. Each granule consists of 6 hours of data. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 22 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Day Julian Day Time GMT in Seconds Latitude Degrees Longitude Degrees V CHANNEL Voltage DV CHANNEL Voltage DVP CHANNEL Voltage N Radiance (w/cm2/steradian) DN Radiance (w/cm2/steradian) DNP Radiance (w/cm2/steradian) CO Parts Per Billion by Volume N2O Parts Per Billion by Volume TBB1 Degree Kelvin TBB2 Degree Kelvin TERTYPE Terrain Type Status TERHGHT Height from Sea Level DN500mb Degrees Kelvin DNP500mb Degrees Kelvin ATTITUDE Attitude Status DAYNGT Day/Night Status CDST Processing Status STWD Instrument Status NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Sample data from the osta3lvl2_1006_00_hdf file: This is from the report file for the osta3lvl2_1006_00 file. *************************** LONGITUDE NO. 1 ****************************** Day: 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 .... Time: 0.00000 1.00000 2.00000 3.00000 4.00000 5.00000 6.00000 7.00000 8.00000 9.00000 10.00000 11.00000 12.00000 13.00000 14.00000 ... Latitude: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 Longitude: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... V CHANNEL: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 DV CHANNEL: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DVP CHANNEL: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... N: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DN: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DNP: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... CO: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... N2O: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBB1: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBB2: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TERTYPE: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TERHGHT: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DN500mb: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DNP500mb: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... ATTITUDE: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DAYNGT: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... CDST: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... STWD: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 5.5 MAPS_SRL1_COSEC_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Space Radar Laboratory - 1 (SRL1) Carbon Monoxide Second by Second Data in Hierarchical Data Format (HDF) (MAPS_SRL1_COSEC_HDF) FILE NAMING CONVENTION: MAPS_SRL1_COSEC_HDF data set files are prefixed with "srl1lv2" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the beginning hour of the day the data were collected for a particular granule. Each granule consists of 6 hours of data. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 22 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Day Julian Day Time GMT in Seconds Latitude Degrees Longitude Degrees V CHANNEL Voltage DV CHANNEL Voltage DVP CHANNEL Voltage N Radiance (w/cm2/steradian) DN Radiance (w/cm2/steradian) DNP Radiance (w/cm2/steradian) CO Parts Per Billion by Volume N2O Parts Per Billion by Volume TBB1 Degree Kelvin TBB2 Degree Kelvin TERTYPE Terrain Type Status TERHGHT Height from Sea Level DN500mb Degrees Kelvin DNP500mb Degrees Kelvin ATTITUDE Attitude Status DAYNGT Day/Night Status CDST Processing Status STWD Instrument Status NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Please refer to the sample record above. (osta3lvl2_1006_00_hdf) INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 5.6 MAPS_SRL2_COSEC_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Space Radar Laboratory - 2 (SRL2) Carbon Monoxide Second by Second Data in Hierarchical Data Format (HDF) (MAPS_SRL2_COSEC_HDF) FILE NAMING CONVENTION: MAPS_SRL2_COSEC_HDF data set files are prefixed with "srl2lv2" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the beginning hour of the day the data were collected for a particular granule. Each granule consists of 6 hours of data. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 22 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Day Julian Day Time GMT in Seconds Latitude Degrees Longitude Degrees V CHANNEL Voltage DV CHANNEL Voltage DVP CHANNEL Voltage N Radiance (w/cm2/steradian) DN Radiance (w/cm2/steradian) DNP Radiance (w/cm2/steradian) CO Parts Per Billion by Volume N2O Parts Per Billion by Volume TBB1 Degree Kelvin TBB2 Degree Kelvin TERTYPE Terrain Type Status TERHGHT Height from Sea Level DN500mb Degrees Kelvin DNP500mb Degrees Kelvin ATTITUDE Attitude Status DAYNGT Day/Night Status CDST Processing Status STWD Instrument Status NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Please refer to the sample record above. (osta3lvl2_1006_00_hdf) INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 5.7 MAPS_OSTA3_LVL1_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Office of Space and Terrestrial Applications - 3 (OSTA3) Level 1 Data in Hierarchical Data Format (HDF) (MAPS_OSTA3_LVL1_HDF) FILE NAMING CONVENTION: MAPS_OSTA3_LVL1_HDF data set files are prefixed with "osta3lv1" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the beginning hour of the day the data were collected for a particular granule. Each granule consists of 6 hours of data. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 27 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Day Julian Day Time GMT in Seconds Latitude Degrees Longitude Degrees V CHANNEL Voltage DV CHANNEL Voltage DVP CHANNEL Voltage N Radiance (w/cm2/steradian) DN Radiance (w/cm2/steradian) DNP Radiance (w/cm2/steradian) TBB1 Degree Kelvin TBB2 Degree Kelvin TBB3 Degree Kelvin TBB4 Degree Kelvin TBB5 Degree Kelvin TBB6 Degree Kelvin TREF Degree Kelvin TBasePlate Degree Kelvin TCELL1 Degree Kelvin TCELL2 Degree Kelvin TDET1 Degree Kelvin TDET2 Degree Kelvin TDET3 Degree Kelvin REF5V Voltage RV Voltage STWD Whole number CB Whole number: 0 or 1 NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Sample data from the osta3lvl1_1006_00_hdf file: This is from the report file for the osta3lv1_1006_00 file. *************************** LONGITUDE NO. 1 ****************************** Day: 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 280.00000 .... Time: 0.00000 1.00000 2.00000 3.00000 4.00000 5.00000 6.00000 7.00000 8.00000 9.00000 10.00000 11.00000 12.00000 13.00000 14.00000 ... Latitude: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 Longitude: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... V CHANNEL: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 DV CHANNEL: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DVP CHANNEL: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... N: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DN: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... DNP: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBB1: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBB2: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBB3: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBB4: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBB5: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBB6: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TREF: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TBasePlate: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TCELL1: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TCELL2: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TDET1: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TDET2: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... TDET3: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... REF5V: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... RV: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... STWD: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... CB: -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 -777.77000 ... INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 5.8 MAPS_SRL1_LVL1_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Space Radar Laboratory - 1 (SRL1) Level 1 Data in Hierarchical Data Format (HDF) (MAPS_SRL1_LVL1_HDF) FILE NAMING CONVENTION: MAPS_SRL1_LVL1_HDF data set files are prefixed with "srl1lv1" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the beginning hour of the day the data were collected for a particular granule. Each granule consists of 6 hours of data. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 27 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Day Julian Day Time GMT in Seconds Latitude Degrees Longitude Degrees V CHANNEL Voltage DV CHANNEL Voltage DVP CHANNEL Voltage N Radiance (w/cm2/steradian) DN Radiance (w/cm2/steradian) DNP Radiance (w/cm2/steradian) TBB1 Degree Kelvin TBB2 Degree Kelvin TBB3 Degree Kelvin TBB4 Degree Kelvin TBB5 Degree Kelvin TBB6 Degree Kelvin TREF Degree Kelvin TBasePlate Degree Kelvin TCELL1 Degree Kelvin TCELL2 Degree Kelvin TDET1 Degree Kelvin TDET2 Degree Kelvin TDET3 Degree Kelvin REF5V Voltage RV Voltage STWD Whole number CB Whole number: 0 or 1 NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Please refer to the sample record above. (osta3lv1_1006_00_hdf) INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 5.9 MAPS_SRL2_LVL1_HDF Data Set This data set is written in NCSA's HDF format. The data files are organized by date. LONG NAME FOR THIS DATA SET: Measurement of Air Pollution from Satellites (MAPS) Space Radar Laboratory - 2 (SRL2) Level 1 Data in Hierarchical Data Format (HDF) (MAPS_SRL2_LVL1_HDF) FILE NAMING CONVENTION: MAPS_SRL2_LVL1_HDF data set files are prefixed with "srl2lv1" to indicate they belong to this data set. This is followed by a four digit number (mmdd) that represents the month and the start day the data were collected. The name is then followed by an underscore and another two digit number that represents the beginning hour of the day the data were collected for a particular granule. Each granule consists of 6 hours of data. The name ends with an underscore followed by the letters "hdf." These three letters inform the user that the data are written in HDF. VARIABLES: This data set contains 27 HDF scientific data sets (i.e., variables) per data file. The variable names are: Variable Units Day Julian Day Time GMT in Seconds Latitude Degrees Longitude Degrees V CHANNEL Voltage DV CHANNEL Voltage DVP CHANNEL Voltage N Radiance (w/cm2/steradian) DN Radiance (w/cm2/steradian) DNP Radiance (w/cm2/steradian) TBB1 Degree Kelvin TBB2 Degree Kelvin TBB3 Degree Kelvin TBB4 Degree Kelvin TBB5 Degree Kelvin TBB6 Degree Kelvin TREF Degree Kelvin TBasePlate Degree Kelvin TCELL1 Degree Kelvin TCELL2 Degree Kelvin TDET1 Degree Kelvin TDET2 Degree Kelvin TDET3 Degree Kelvin REF5V Voltage RV Voltage STWD Whole number CB Whole number: 0 or 1 NOTES ON DATA: Dimension lengths show above may vary between files due to variations in the amount of data collected per flight track. FIRST RECORD OF DATA FROM FIRST DATA GRANULE: Please refer to the sample record above. (osta3lv1_1006_00_hdf) INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov INSTRUMENTATION: The MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data. CONTACT FOR DATA PRODUCT INFORMATION: Dr. Vickie S. Connors NASA LaRC, Atmospheric Sciences Division Mail Stop 401A Hampton, VA 23681-2199 U.S.A. Tel: (757) 864-5849 E-mail: v.s.connors@larc.nasa.gov 6.0 Implementation Notes Section 6.0 gives the user a brief explanation on how to run the sample read software. 6.1 MAPS CO5X5 Read Program There is only one version of the read program available for these data set (MAPS_OSTA3_CO5X5_HDF, MAPS_SRL1_CO5X5_HDF, and MAPS_SRL2_CO5X5_HDF). The following represents a sample execution of the C program, maps_co5x5_read.c. sorcerer% read_maps_co5x5 ***************************************************** * * * MAPS Read Program Version 2.0 * * * * * * This sample read program currently reads the * * following data sets: * * * * MAPS_SRL1_CO5x5_HDF * * MAPS_SRL2_CO5x5_HDF * * MAPS_OSTA3_CO5x5_HDF * * * * * * 02-02-1999 * ***************************************************** Enter the input data file name. This code assumes file is in your current working directory. srl15x5_0409_09_hdf In your output report file, do you want to include the file description? Enter 1 for yes and 2 for no.... 1 Would you like to have the program write out all of the parameters? Enter Y for yes or N for no. --> y Reading labels.... There are 72 records/number of events in the HDF file. NOTE: This will take some time to write out the report file. Reading data, Please wait... ... and wait... @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ @ @ This program has completed and has created an output report @ @ file called./srl15x5_0409_09_hdf.rpt in your current @ @ working directory. @ @ @ @ @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 6.2 MAPS COSEC Read Program There is only one version of the read program available for these data set (MAPS_OSTA3_COSEC_HDF, MAPS_SRL1_COSEC_HDF, and MAPS_SRL2_COSEC_HDF). The following represents a sample execution of the C program, maps_co5x5_read.c. sorcerer% read_maps_cosec ***************************************************** * * * MAPS Read Program Version 2.0 * * * * * * This sample read program currently reads the * * following data sets: * * * * MAPS_SRL1_COSEC_HDF * * MAPS_SRL2_COSEC_HDF * * MAPS_OSTA3_COSEC_HDF * * * * * * 02-02-1999 * ***************************************************** Enter the input data file name. This code assumes file is in your current working directory. osta3lv2_1006_00_hdf In your output report file, do you want to include the file description? Enter 1 for yes and 2 for no .... 1 Would you like to have the program write out all of the parameters? Enter Y for yes or N for no. --> y Reading labels.... There are 12 records/number of events in the HDF file. NOTE: This will take some time to write out the report file. Reading data, Please wait ... Data are printed from left to right in event order. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ @ @ This program has completed and has created an output report @ @ file called ./osta3lv2_1006_00_hdf.rpt in your current @ @ working directory. @ @ @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 6.3 MAPS COSEC Read Program There is only one version of the read program available for these data set (MAPS_OSTA3_LVL1_HDF, MAPS_SRL1_LVL1_HDF, and MAPS_SRL2_LVL1_HDF). The following represents a sample execution of the C program, maps_lvl1_read.c. sorcerer% read_maps_lvl1 ***************************************************** * * * MAPS Read Program Version 2.0 * * * * * * This sample read program currently reads the * * following data sets: * * * * MAPS_SRL1_LVL1_HDF * * MAPS_SRL2_LVL1_HDF * * MAPS_OSTA3_LVL1_HDF * * * * * * 02-02-1999 * ***************************************************** Enter the input data file name. This code assumes file is in your current working directory. osta3lv1_1006_00_hdf In your output report file, do you want to include the file description? Enter 1 for yes and 2 for no .... 2 y Would you like to have the program write out all of the parameters? Enter Y for yes or N for no. --> Reading labels.... There are 12 records/number of events in the HDF file. NOTE: This will take some time to write out the report file. Reading data, Please wait ... Data are printed from left to right in event order. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ @ @ This program has completed and has created an output report @ @ file called ./osta3lvl1_1006_00_hdf.rpt in your current @ @ working directory. @ @ @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Updated: February 1, 1999 LD_008_015_001_00_00_0_19990201 Updated: February 1, 1999 LD_008_015_001_00_00_0_19990201 Updated: July 20, 1999 LD_008_015_001_00_00_0_19990201 Updated: March 20, 2012 User Services email