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UPDATED SOFTWARE FOR IONOGRAM RECORDING AND ANALYSIS.

J.E. Titheridge, Physics Department, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
email:
j.titheridge@auckland.ac.nz.

"Digion" Ionogram Data.

The popular KEL IPS-42 ionosonde can be controlled by a microcomputer, to obtain digital ionograms. The data are commonly stored on magnetic tape cartridges. Unfortunately this medium has proved unreliable, with some cartridges producing numerous tape errors. With the compressed tape format normally used (and the compressed nature of the basic data), one error makes the remainder of the file unreadable. A new computer program FIXION has been developed to scan daily ionogram files and report any errors. The program can then be used to find all useable ionograms and write them into a new, uncorrupted, file - this typically saves over 95% of the data. The source programs Fixion.c, and a compiled version Fixion.exe, have been placed in a DIGION subdirectory of the ftp site set up by IPS, at ftp_out.ips.gov.au/users/phil/digion

Updated versions of the program Digion, used for viewing and scaling the ionogram data, are also available from this site. A further utility Dignum has been produced to change the site number on all ionogram files, if required, and to set a fixed "offset" that may be desired to correct for receiver delay, etc. The operation of all programs is summarised in a Readme file. Further programs to produce real-height profiles directly from the scaled data, using the program POLAN, may become available in 1998.

"Digion" Hardware

There may be some who are still using a KEL IPS-42 and storing the ionograms on film - or who have stopped recording, because of the cost and inconvenience of film records. You should note that the hardware and software for using any simple P.C. to control the ionosonde, and collect accurate digitised data at any required intervals, is still available from the author. The equipment consists of a plug-in board for the computer, a small board that wires into the rear of the ionosonde, all necessary cables and connectors, full software (with source code) and instructions. The full system costs US$1600, and can be used with most 'obsolete' computers (286 or later). For high-resolution ionograms recorded at 5 min intervals, storage requirements are about 1MB per day. Thus a single 100 MB ZIP cartridge will hold all data for six months, using normal data compression, giving reliable storage and fast access. For further information on this system, used at over 20 sites around the world, contact me or see the articles in INAG-60 (Nov. 1993) or UAG Report 104 (from the World Data Centre A).

Real-Height Analysis Using "Polan"

Minor updates have been made to POLAN over the last several years, and a larger revision (primarily to improve the model valley assumed between the E and F layers) is planned for mid 1998. All of the POLAN programs are also now available on the IPS site, at ftp_out.ips.gov.au/users/phil/polan. Anyone using a version without the December 1995 updates (as described at the beginning of POLAN.FOR) should obtain the new files. Again could users experiencing any problems please email me with copies of the offending data and the corresponding output. The programs have been well tested, over many years, but every data set is different and feedback is essential to make improvements and help with problems. Thus one group recommended to others (but not to me!) that frequent bombs made POLAN unusable with x-ray data; I found later that ALL their bombs were due to a faulty copy of POLAN. Don't let this happen to you!

Use of the IPS site for ftp transfers should make it much simpler for people to obtain copies of the latest programs, and I am most grateful to Phil Wilkinson for making this route available.

Note from Phil Wilkinson:

if you have problems using the ftp site, please send me e-mail at phil@ips.gov.au.
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