gov.noaa.ngdc.stp.ionosonde:G00551User ServicesDOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce19570101The standard (analog) ionosonde produces photographic records known as ionograms, which show the variations of the virtual height of reflection as a function of the radio frequency. The frequency band normally used is from about 1 MHz to about 20 MHz though some ionosondes operate down to about 0.20 MHz and up to 30 MHz. The ionograms actually show the time of travel of the pulse signal from the transmitter to the ionosphere and back to the receiver. A given station typically generates a sweep-frequency ionogram in about two minutes. Normally four ionograms are taken per hour, one at each quarter hour. As of May 1994, there are approximately 16,140 rolls of ionogram film at our Data Center. Most of these photographic records (ionograms) were recorded on 35mm film, but there are some 16mm ionogram film. One month of 35mm ionograms averages about 800 feet of film. These rolls of film are kept off site but can be retrieved when needed. If you would like to study specific ionograms, researchers are welcome at the National Geophysical Data Center, but are requested to give adequate advance notice of their visit so that appropriate arrangements may be made for their work space at the Data Center. Some ionograms were digitized and are stored in TIF G4 format.Research - Radio Frequency Reflection19440301UnknownUnknownIn workcontinual-180.000000180.00000090.000000-90.000000NASA/GCMD Earth Science KeywordsEARTH SCIENCE > SOLAR PHYSICS > Solar Energetic > Particles > Particle DensityUncontrolled KeywordsIonosondeBottomsideIonogramsSpace Physics - Ionospheric ScienceNASA/GCMD Data Center KeywordsWDC/STP, BOULDER > World Data Center for Solar-Terrestrial Physics, BoulderDOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of CommerceNASA/GCMD Location KeywordsGlobalRestriction Code: otherRestrictions; Use Limitation: While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.; Other: Use Constraints: None; Other: Access Constraints: No Constraints; DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of CommerceJustin Mabiephysical and mailing NOAA/NESDIS/NGDC 325 Broadway BoulderCO80305(303) 497-6135ionosonde@noaa.govUnknown 20100907Justin MabieDOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commercemailing and physical 325 Broadway, Mail Code E/GC4 BoulderCO80305-3328(303) 497-6135Justin.Mabie@noaa.govContent Standard for Digital Geospatial Metadata: Extensions for Remote Sensing MetadataFGDC-STD-012-2002