ISIS Topside Sounder ionogram header files in ASCII format

This directory contains ionogram header files for the ISIS 1 and 2 topside sounder 
ionogram passes. These data were provided as part of an OSS/AISRP data restoration 
project at GSFC (R. Benson, PI). Each ASCII header file includes the header 
information for each ionogram during the specific satellite pass. More information 
about the ISIS project can be found at http://spdf.gsfc.nasa.gov/isis/isis-status.html.

Format Description: http://nssdc.gsfc.nasa.gov/space/isis/header.html

Subdirectories:
/sss_lat_long/isis&/yyyy   
	'sss' is the 3-digit identification code of the ground station (a list 
	   of stations can be found at http://nssdc/space/isis/isis-table1-new.html); 
	'lat' and 'long' are the geodetic latitude and longitude of the ground station.
	'isis&' is either 'isis1' or 'isis2'
	'yyyy' is the 4-digit year

A search page (http://nssdc.gsfc.nasa.gov/space/isis/isis_menu4.html) lets users
locate data for specified dates, times, locations and other search criteria.

Selected ISIS ionogram data are accessible for viewing and downloading on CDAWeb 
at http://cdaweb.gsfc.nasa.gov/. The list of accessible files can
be found at http://spdf.gsfc.nasa.gov/isis/data_list.html.

Please acknowledge the NASA Space Physics Data Facility and the instrument's Principal
Investigator for data usage.

Keywords: ionosphere, topside, sounder, ionogram

Data contact: Dieter.Bilitza-1@nasa.gov>
NASA Official: Dr. Robert McGuire <robert.e.mcguire@nasa.gov>