TY - CONF AU - Weiss, Marc AU - Jefferts, Steven AU - Gaudron, L C2 - 10^uth^ European Frequency and Time Forum , Brighton, UK DA - 1996-01-01 LA - en PB - 10^uth^ European Frequency and Time Forum , Brighton, UK PY - 1996 TI - Improving the NIST Ionospheric Measurement System ER -