{"@type": "dcat:Dataset", "accessLevel": "public", "bureauCode": ["026:00"], "contactPoint": {"@type": "vcard:Contact", "fn": "NASA Space Physics Data Facility", "hasEmail": "mailto:NASA-SPDF-Support@nasa.onmicrosoft.com"}, "description": "This set of key parameters from the SESAME (Satellite Experiments Simultaneous with Antartic MEasurements) ground-based experiment contains ionospheric parameters that are derived from quarter-hourly ionograms. The three parameters include the lowest plasma frequency recorded and the highest plasma frequency recorded from the E-region (MHz), and the highest plasma frequency recorded from the F-region (MHz). Please see references: (1) Grubb, RN, The NOAA SEL HF Radar system (ionospheric sounder) NOAA Tech Memo ERL SEL-55, Space Environ Lab, Boulder, CO, 1979, (2) Jarvis,MJ and Dudeney ,JR Reduction of ambiguities in HF radar results through a revised receiving array and sounding pattern. Radio Sci 21, 151-158, 1986, and (3) Dudeney, J. R. et. al., Satellite Experiments Simultaneous with Antarctic Measurements (SESAME), Space Science Reviews, Volume 71, Issue 1-4, pp. 705-742, 1995.", "identifier": "/SDE/SPASE_JSON/|46a57e5c75a03b62a1776ec0866614c0", "keyword": ["thermalplasma"], "license": "https://www.usa.gov/government-works", "modified": "2026-04-06", "programCode": ["026:000"], "publisher": {"@type": "org:Organization", "name": "NASA Space Physics Data Facility (SPDF) Data Services"}, "theme": ["Heliophysics"], "title": "SESAME Advanced Ionospheric Sounder, Key Parameters"}