TOMS/Nimbus-7 Ground Station Overpass Data V008 (TOMSN7OVP) at GES DISCEntry ID: GES_DISC_TOMSN7OVP_V008
Abstract: This data product contains TOMS/Nimbus-7 Ground Station Overpass Data Version 8 in ASCII format. The overpass data files contain the data derived from the best-matched TOMS field-of-view (FOV) to a site for every day the TOMS instrument was operational.
Four TOMS instruments were successfully flown on the following satellites: Nimbus-7 (Nov. 1978 - May 1993), Meteor-3 (Aug. 1991 - Dec. 1994), ... Earth Probe (July 1996 - current), and ADEOS (Sep. 1996 - June 1997). The TOMS Earth Probe, Meteor-3 and Nimbus-7 data were reprocessed using the Version-8 algorithm by the Laboratory for Atmospheres at NASA Goddard Space Flight Center (Code 614).
Each overpass file contains four (4) header records, followed by all the data records.
The file header consists of four (4) records:
1. Site name, ID, and location.
2. Overpass program run information
3. Column headings
4. Marker record.
An example of the first header record is:
Edmonton/Stony Plain, Canada ID: 21 Lat: 53.55 Lon: -114.10 Alt: 766
In this example, the site ID number is 21, the latitude is 53.55N and
longitude is 114.10E, and the verified elevation is 766 m (above sea level).
The FORTRAN format code for reading the first header record is:
(A30, 4X, I3, 7X, F7.2, 7X, F7.2, 7X, I4)
An example of the second header record is:
Nimbus 7 TOMS V.8 Archive Overpass. Generated: 1-January-1993
This indicates the spacecraft instrument, the data version used to generate
the overpass data, and the date on which the file was generated (created or
The third header record contains the column headings for the data records.
The header looks like this:
MJD Year Day sec-UT SCN LAT LON DIS PT SZA OZONE REF A.I. SOI
The contents of each column is described below in the section on Data
The fourth header record simply contains a pound-sign (#) in the first
column, and signals that the data begin with the next record in the file.
Each data record contains fourteen (14) values. They are as follows.
MJD Modified Julian Day. Astronomical Julian Day number, less
2,400,000.5. The number is given to the nearest 1/10 day.
Year The four-digit Gregorian year number of the TOMS measurement.
Day The day number (day 1 through 366) of the TOMS measurement.
sec-UT The number of seconds from midnight, Universal Time. on the day
specified by Year and Day.
SCN TOMS instrument scan position (1--35 for N7, M3, EP; 1--37 for
LAT Latitude of the center of the IFOV.
LON Longitude of the same.
DIS Distance from site and IFOV center position, in km.
PT Terrain pressure at IFOV center, in (atm x 100)
SZA Solar zenith angle, in degrees, at time and location of IFOV
OZONE TOMS best total ozone, in Dobson Units (DU)
REF TOMS reflectivity at 380 nm (N7, M3) or 360 nm (EP,
A.I. TOMS aerosol index.
SOI TOMS sulfur dioxide index.
The FORTRAN format code for reading a data record is:
(F7.1, 1X, I4, 1X, I3, 1X, I5, 2X, I2, 1X, F6.2, 1X, F7.2, 1X,
I3, 1X, I3, 1X, F5.2, 1X, F5.1, 1X, F5.1, 1X, F6.2, 1X, I4)
Purpose: This product can be used to compare TOMS with ground station data.
(Click for Interactive Map)
Data Set Citation
Dataset Originator/Creator: TOMS Science Team
Dataset Title: TOMS/Nimbus-7 Ground Station Overpass Data
Dataset Release Date: 1993
Dataset Release Place: Greenbelt, MD, USA
Dataset Publisher: NASA Goddard Earth Science Data and Information Services Center
Data Presentation Form: Digital Science DataOnline Resource: http://disc.gsfc.nasa.gov/
Start Date: 1978-11-01Stop Date: 1993-05-06
ISO Topic Category
Role: DIF AUTHOR
Role: TECHNICAL CONTACT
Phone: +54-21-21-7308 x38
Phone: +54-21-3-8810 x38
Email: jcg at fcaglp.edu.ar
Departamento de Magnetismo Terrestre y Electricidad Atmosferica Facultad de Ciencias Astronomicas y Geofisicas Paseo del Bosque s/n
City: La Plata
Postal Code: 1900
Creation and Review Dates
Last DIF Revision Date: 1995-10-11