The Federal Register, among other things, can tip you off to developing problems in the defense area.

The March 24 issue (page 18328) announced a meeting on April 21-22 of the Defense Science Board Task Force on Mapping, Charting and Geodesy to "review the Defense Department's plans and programs . . . critical to the guidance of cruise missiles and other future weapons systems."

Early last month, the General Accounting Office released a study sharply criticizing the cruise missile program. These key missiles, which are still being developed, are to be used both as strategic weapons, launched from B52s, and theater weapons in Europe, launched from the ground.

Proponents describe them as simple to make and wonderful in performance.

The warhead sits on the front of a jet engine that flies toward its target at a low altitude, tracing its course by a navagation system and a computerized radar altimeter that matches the ground it passes over to a contour map that has been stored in its electronic brain. As the data picked up from the ground is matched to the map, the missile makes its own corrections and, it is hoped, flies directly to its target.

As the GAO has pointed out, recent cruise missile tests have shown that although the missile "demonstrated an ability to follow the terrain, this, for the most part, was accomplished at flight levels significantly higher" than required to keep it below enemy radar.

One test missile that flew lower than the others "narrowly missed crashing into a hill."

Another problem was that the areas over which the missiles were flown in the test were "not nearly as smooth as much of the terrain over which the missiles will have to fly in the case of a European conflict" or "some areas in the Soviet Union where more level terrain may make the guidance system's functioning more difficult."

In relating the tests to future operations, GAO said the detailed, contour maps that would have to be placed in the electronic brain of the cruise missile planned for the European theater do not exist and that "high quality source data . . . may not be available for operational areas."

Enter the Defense Science Board Task Force on Mapping, Charting and Geodesy. The April 21-22 sessions, according to the Register notice, will be concerned with having the distinguished, nongovernment scientists who make up the group review Defense Department plans and programs for generating the collection and transmission of just this type of data. Don't try to attend the sessions scheduled for the DMA Aerospace Center in St. Louis, because understandably they will be closed to the public.