1. Developing the Sessions
   • Your first job as program chair will be to prepare a list of special sessions to appear in Eos. Generally, AGU will want this information about 6 months before the meeting (they will contact you), so you should plan accordingly. Ideas for special sessions should be solicited from the geodetic community (e.g. via e-mail), and you should attempt to get commitments to chair these sessions as well, since the next call for Eos will require titles, session descriptions, and session chairs. You may not get enough good suggestions for sessions as you would like, so you should be prepared to create a few sessions on your own. It is a good idea to ask some of the newer scientists to chair sessions, since they are most in need of the experience/exposure. Also, it is fine to have co-chairs, but not required.
   • Generally, a typical AGU meeting will include about 10-12 Geodesy oral and poster sessions, with each session being about a half day long. Some sessions will run a whole day (2 half day sessions) if the turnout is good. The geodesy program is composed of the special sessions which you have organized, as well as sessions containing contributed papers which were not targeted for a special session. It is the program chair's job to organize the contributed papers into oral and poster sessions covering related topics.
   • There are no firm rules on the number of special versus contributed sessions for the AGU meeting. In a perfect world, there would only be a few special sessions, and most people would simply contribute papers that the program chair would organize into sessions. However, in recent years the trend has been more towards almost entirely special sessions, since this seems to encourage a good turnout for the meeting. Over the last few years, the geodesy program chairs have generally organized about 8 special sessions for each meeting, with the rest of the program filled in with contributed talks. On occasion, as many as 10 special sessions have been planned, but some of these were joint sessions with the other sections. Wherever needed, the geodesy sessions should be made joint with the other sections (Oceans, Tectonophysics, Planetology, etc.). This will also improve the turnout.
   • You should instruct your session chairs to invite no more than a half dozen people to speak in their session. This helps insure that there will be enough abstracts to have a viable session. In addition, it frees the speaker from AGU's 1 first authored abstract rule, which doesn't apply to invited papers. Inviting speakers is probably the most important job of the session chairs. If they show reluctance to inviting speakers then you should probably find a different chair, unless there are unusual circumstances. In this regard, the enthusiasm of the session chair is almost always proportional to the success of the session.
2. Developing the Meeting Program
   • The program chair's meeting at AGU is held about 2 months before the main meeting. Recently, AGU began using a database program to do the scheduling, so if you have a Mac or PC laptop computer, bring it along. Get AGU to send you the database program ahead of time so that you can get familiar with it. Before you go to the meeting, AGU will send you all the abstracts, and you should fax the abstracts for each session to the respective session chairs so that they can order the abstracts themselves. The sessions chairs will often spot missing abstracts during this procedure as well. At the program chair's meeting, AGU will tell you how many rooms the Geodesy Section has been allocated for oral sessions. You will then have to make the difficult decision of which sessions should be oral versus poster format. You might ask your session chairs if they want to volunteer for a poster session, since some sessions emphasizing visual images might prefer this format. An oral session generally consists of thirteen 15 minute talks, less if you make the invited talks 20 minutes long (optional). For sessions with a lot of abstracts (> 20), you might want to have one oral session and one poster session, or possibly two oral sessions if you really want to highlight that research. Here are some general rules of thumb regarding scheduling oral/poster sessions:
     • Never schedule an oral session simultaneously with a poster session (even if the topics are different); its just too hard to get from the poster area to the oral sessions.
     • Its perfectly fine, even preferable, to schedule several poster sessions simultaneously; people won't mind spending an afternoon at the posters if there are a lot of them and there are no competing oral sessions.
     • Scheduling oral sessions simultaneously is fine as long as you follow the rules of thumb given below to avoid conflicts.
     • Generally, you will want to use all the rooms available to you for oral sessions, and then cover the rest of the program with poster sessions.
     In the end, the choice of which sessions are oral versus poster is pretty arbitrary. Try to consider the follow: a) the suitability of the topic to an oral/poster sessions, b) the strength of the papers in each session, and c) the format (oral/poster) for this topic at previous meetings.
   • As program chair, your most important job will be to organize the geodesy part of the AGU meeting so that there are as few of conflicts as possible between sessions (both Geodesy and the other sections). This requires at least a working knowledge of the different research that is being done in the Geodesy Section, as well as its relation to similar research being presented in the other sections. Some general rules of thumb:
     • Watch for sessions with similar science topics, and don't schedule these sessions opposite each other. Be especially vigilant of the sessions planned by the Oceans, Seismology, and Tectonophysics sections. Union sessions can also cause conflicts.
     • Watch for sessions emphasizing similar geodetic techniques (i.e., don't schedule ocean altimetry versus ice altimetry, or GPS Vertical Positioning versus GPS Reference Frames). While someone might only be presenting in one session, they are often interested in how the same geodetic technique is being applied in other applications.
     • A good way to spot conflicts is to keep track of the authors participating in each of the sessions, making sure that the cross-interests are minimized.
     Unfortunately, it is impossible to spot all the possible conflicts. Therefore, you may wish to send a list of the session titles to each of your program chairs and have them mark the sessions they think may conflict with their session.
   • For all the contributed sessions, and most of the poster sessions, you will find yourself in the position of not having sessions chairs. You should be prepared to come up with names for these slots, and you will probably want to call these people from AGU Headquarters during the program meeting in order to confirm their participation.
   • Finally, you should generally schedule the meeting over the entire 5 days, and AGU will encourage you to do so. In an unusual circumstance when you don't get a lot of abstracts, you may be able to comfortably fit all of the sessions into the first 4 days of the meeting, but this is not the norm.

Steve Nerem
University of Colorado at Boulder