Abstractomega is a verylong‐range VLF navigation system generating hyperbolic lines‐of‐position by phase difference measurements of 10.2 kc/s time‐shared transmissions. A new multi‐frequency signal format is described which will increase the system utility. The background, theory, and results of a six‐year developmental effort on theomeganavigation system are presented. A worldwide system employing eight stations is feasible. Such a system would be straightforward in use and have an accuracy of one‐half to one mile. Operational results of twenty‐five shipboard installation