U.S. Department of Commerce NTIA/ITS
Institute for Telecommunication Sciences
IF-77 Electromagnetic Wave Propagation Model (Gierhart-Johnson)

Unfortunately, all of the documentation for this model is in paper form. This was developed before word processors were common.
We are no longer able to supply copies of the documentation, but they are available through the National Technical Information Service (NTIS®), Springfield, Virginia 22161.
The following list contains the NTIS Accession numbers and the document titles:
  • ADA-134504 - ($34.00) The IF-77 Electromagnetic Wave Propagation Model
    • by G.D. Gierhart and M.E. Johnson, DOT/FAA/ES-83/3, September 1983.
  • ADA-076508 - ($84.00) Comparison of Measured Data with IF-77 Propagation Model Predictions,
    • by M.E. Johnson and G.D. Gierhart, FAA-RD-79-9, August 1979.
  • ADA-088153 - ($41.00) An Atlas of Basic Transmission Loss for 0.125 to 15.5 GHz,
    • by M.E. Johnson and G.D. Gierhart, FAA-RD-80-1, August 1980.
  • ADA-053242 - ($51.00) Applications Guide for Propagation and Interference Analysis Computer Programs (0.1 to 20 GHz)
    • by M.E. Johnson and G.D. Gierhart, FAA-RD-77-60, March 1978.
  • ADA-122582 - ($34.00) Use of the Longley-Rice and Johnson-Gierhart Tropospheric Radio Propagation Programs: 0.02-20 GHz
  • ADA-063792 - ($67.50) Aerospace Propagation Prediction Capabilities Associated with the IF-77 Model
  • The above prices were quoted by NTIS on 6/2/2000.
  • Foreign prices are double.
  • There may also be a shipping fee.
  • Since they are over 10 years old, they are NOT available on the NTIS web site.
  • You can call NTIS at: 800-553-6847.
  • You can FAX a request to NTIS at: 703-605-6900.
The work was performed under contract to the U.S. Department of Transportation (DOT), contract number DTFA01-82-Y-10539. The report is titled:
The IF-77 Electromagnetic Wave Propagation Model (DOT/FAA/ES-83/3), September 1983.
by G.D. Gierhart and M.E. Johnson
U.S. Department of Commerce
National Telecommunications and Information Administration
Institute for Telecommunications
Boulder, Colorado 80305

Abstract:

The IF-77 propagation model is applicable to air/ground, air/air, ground/satellite, and air/satellite paths. It can also be used for ground/ground paths that are line-of-sight or smooth earth. Model applications are restricted to telecommunication systems operating at radio frequencies from about 0.1 to 20 GHz with antenna heights greater than 0.5 m. In addition, radio-horizon elevations must be less than the elevation of the higher antenna. The radio horizon for the higher antenna is taken either as a common horizon with the lower antenna or as a smooth earth horizon with the same elevation as the lower antenna effective reflecting plane.

Disclaimer:

The software contained within was developed by an agency of the U.S. Government. NTIA/ITS has no objection to the use of this software for any purpose since it is not subject to copyright protection in the U.S.

No warranty, expressed or implied, is made by NTIA/ITS or the U.S. Government as to the accuracy, suitability and functioning of the program and related material, nor shall the fact of distribution constitute any endorsement by the U.S. Government.

The following files are available from this ITS web site:

ata.exe An executable file for ATA. Runs on a PC under DOS. (changed 8 Sep 2000)
atoa.in Sample input file for ATA. Run with: ata < atoa.in > atoa.out
atoa.out Sample output file for ATA.
cards.txt Text description of data input cards.

Source file for ata.for
Source file for aalos.for
Source file for amsc.for (changed 8 Sep 2000)
Source file for asorp.for

Brought to you by: TA Services Support.
For technical questions, contact: George Hufford (retired), Email: ghufford@its.bldrdoc.gov  Phone: (303) 497-3457

U.S. Department of Commerce
National Telecommunications and Information Administration
Institute for Telecommunication Sciences
NTIA/ITS.E
325 Broadway
Boulder, Colorado 80305