@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

<https://gcmd.earthdata.nasa.gov/kms/concept/4190ebdc-e89a-4f3f-bc74-b2af4c68d009>
  skos:prefLabel "Profilers/Sounders"@en ;
  a skos:Concept ;
  skos:narrower <https://gcmd.earthdata.nasa.gov/kms/concept/36bad2be-728a-4797-b913-f204d5f8902a> .

<https://gcmd.earthdata.nasa.gov/kms/concept/36bad2be-728a-4797-b913-f204d5f8902a>
  skos:definition """Ionosondes and Digisondes are devices that send a spectrum of
radio wave pulses straight up (vertically incident to the
ground).  They measure the length of time it takes for a
reflection to be returned, the strength of the reflection, and
how high of a frequency can be reflected.

From these three data points (time, strength, frequency), the
device can determine ionization density, altitude of the
ionization, and potential Maximum Useable Frequency (MUF).

Output from ionosondes and digisondes are displayed in the form
of an "ionogram", or displayed in a tabular data format

Additional information available at
"http://www.amfmdx.net/fmdx/ionosonde.html\""""@en ;
  skos:prefLabel "DIGISONDES"@en ;
  skos:inScheme <https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/instruments> ;
  skos:broader <https://gcmd.earthdata.nasa.gov/kms/concept/4190ebdc-e89a-4f3f-bc74-b2af4c68d009> ;
  a skos:Concept .