1. COMMENTS FROM THE CHAIR

Our meeting was quieter in Kyoto with the absence of Jurgen Buchau who died, suddenly, on August 9, 1993. His enthusiasm will be missed by all of us. I can remember the first and last times I met Jurgen and I wish there were many more occasions between than time allowed.

The preparation of this Bulletin has been delayed somewhat by the production of the UAG Report on Ionosonde Networks and Stations. This report will be sent to all INAG Members in 6 to 8 weeks. The introductory comments are included here to give you a taste of what was covered in the oral and poster sessions and also what will be appearing in the UAG report.

This collection of papers forms the bulk of the papers that were presented, either orally or as Poster papers, at the 1993 Kyoto URSI General Assembly session sponsored by the URSI Commission G Working Group INAG (Ionosonde Network Advisory Group).

The ionosonde has been used to measure ionospheric information for over fifty years. During much of this time it has been a routine instrument, data often being processed months after recording. For long term measurements of the climate of the ionosphere this is adequate. However, it is now inescapable that if ionosonde stations cannot offer a more timely service, so that the data can be used in near real time, they will cease to be funded. This situation has been developing over the last decade and has both positive and negative aspects to it. On the negative side, many ionosonde stations are now threatened with closure because upgrading of equipment to deliver real time data is economically unrealistic. Some indication of these problems are presented in the papers by Baker and Shirochkov.

On the other hand, more modern ionosondes, coupled with automatic scaling methods and a greater appreciation of the value of real time ionospheric data show this challenge can be met. The potential that can be realised with modern ionosondes is demonstrated in papers by Reinisch and Buchau et. al. New ionosondes are discussed in MacDougall et. al. and Akchyurin et. al. while Titheridge outlines a low cost method for upgrading a film based IPS-42 ionosonde to record digital records. Several papers (Pulinets, Igi et. al., Poole et. al., Vugmeister et. al. and Bakhitzhqan et. al.) discuss automatic processing of ionosonde records in varying degrees of detail accompanied by comments on applications for the data. Applications of ionosonde data for frequency management (Lynn) forecasting (Minullin et. al.), climate monitoring (Eliseyev) and as a new ionosonde site (Shaptev) are discussed. These papers offer views regarding the future deployment and use of ionosonde data in a range of applications.

Allied with these papers are papers on techniques, eg. Nozaki, and new analysis methods for the data recorded (Tsai et. al., Denisenko et. al. and Weixing Wan et. al.). Several papers report on the results of analysing ionosonde data to improve forecasting methods (Gulyaeva, Bowman and Igarashi et. al.) and for improving models (Chong et. al., Shun-rong Zhang et. al. and Bradley et. al.). Finally, two papers develop oblique propagation (Blagoveshchensky et. al.) and transionospheric propagation (Danilkin) ideas.

The ionosonde has already made a valuable contribution to our knowledge of the ionosphere and it is hoped it will continue to make an equally valuable and enlarged contribution in the years to come. This collection of papers offers an insight into the wide range of ways ionosonde collection and data use is changing in response to changing economic times.

I felt this session went well at URSI and look forward to the session INAG will be responsible for in 1996. Please note the topic and consider now what you will be submitting. I hope we can have a good overview of the methods people are using to scale ionograms using the computer. These techniques are now used widely although, as far as I am aware, few data are being archived directly from computer scaling programs.

I am sorry that another ionosonde station has had to close. Maui ionosonde station is a long established station, having run for over 50 years, sited in an equatorial region and remote from other ionosonde stations. The loss of sites such as this is particularly important and we will all hope that it is only a temporary situation and that some replacement station can be reopened in the region, preferably before the next solar cycle has commenced. Maui satisfied most, if not all, the criteria for a key station and demonstrates how fragile these concepts are. Last year I was asked to offer comments on the closure of the South African ionosonde network. I have reproduced my comments in this Bulletin. Many of us are asked, from time to time, to offer comments of a similar nature on the future of ionosonde stations and networks. It would be most helpful if everyone could share their comments with us in the Bulletin. I feel we can all gain some insights and, most likely, some useful phrases and arguments we can adapt to our needs when we are next called on to offer support. If we cannot support each other in these ways, we will have little chance of convincing better organised groups we are serious.

Another interesting exercise arose from the questionnaire I circulated last year. I was asked to prepare a literature search on ionosonde papers. The results of a moderately comprehensive search appears later in the Bulletin. By the time you read this the American Geophysical Union will have confirmed its key words for the next publishing year. In setting up this list they have removed all reference to types of recording equipment. The AGU key word list is now science oriented, but of no value to groups such as INAG who would like to keep track of publications whose contents depend on particular equipment. While I have indicated my feelings to the AGU Working Group I am not optimistic that a change will be made at this stage. I feel the key word listing should definitely contain a reference to equipment and all authors should be encouraged to indicate at least one key word noting where any data they used came from. Before I claim this is an INAG viewpoint, I would appreciate hearing other opinions on this topic.

This bulletin features a four articles on ionosondes and ionosonde suppliers. The latter is a table I have prepared and I am unsure that it is complete. I will reprint this table in the next Bulletin if there are any changes to it.

There are three papers on two new ionosondes and an upgrade for the IPS-42 ionosonde. IPS has installed several of John Titheridge's digion boards in our 4B ionosondes and we are very happy with the results. We have now eliminated our reliance on film records at all our sites. This raised an interesting issue we had not previously considered. The costs of running an ionosonde station are not small, yet often the final step of recording the data is the most risky aspect of the exercise. Retrospectively, it is hard to understand why ionosondes were not equipped with two cameras, for instance. I have worked out that around 80% of all the data IPS has lost over the last 20 years can be directly attributed to a failure of the recording medium (poor representation on the oscilloscope, poor film handling). Any digital system can minimise this risk first by eliminating the film stage completely, and then, more importantly, by producing multiple copies of the original ionogram at the recording stage. At IPS we are now copying the raw ionogram to a DAT tape, storing it on the hard disk of the computer and copying it to a floppy disk. Shortly we will add down loading to a central computer as well. While this appears unnecessary duplication, it costs very little to do and it limits the risk of not getting a useful record due to a failure of one of the modes of record delivery. We also collect a film record, because the digion allows it, but this would only be used if the computer failed. I would strongly recommend everyone consider how secure their systems are in delivering a raw ionogram to an archive.

Thank you to the contributors for this issue of the INAG Bulletin. Five of the submissions were prepared from text supplied to me either on disks or by email. If you are preparing an article, I would much prefer to receive it by email, or on a disk, as this greatly eases the handling problems at my end.

INAG email Directory

Finally, I would like to make up an email address list for INAG members. If you use email, could you send me a message so I can confirm your address. I will include an INAG email directory in the next Bulletin.

Phil Wilkinson, Chair, INAG.