Earth Sciences
E01  Geodesy
E02  Geodynamics, geophysics and oceanography
E03  Global tectonics
E04  Reference frames
E05  Ionosphere / space weather
E06  Troposphere / climatology
E07  Disaster monitoring
E08  Gravity field
E09  GNSS remote sensing, GNSS reflectometry

Physics
P01  Test of General Relativity and alternative theories 
P02  Fundamental constants
P03  Relativistic reference frames
P04  Relativistic positioning
P05  Astrometry, VLBI, pulsar timing 
P06  Quantum technologies for positioning, navigation and timing

Metrology
M01  Atomic clocks for space and ground-segment
M02  Galileo timing system
M03  Time scales and time transfer
M04  Inter-satellite links
M05  Satellite Laser Ranging
M06  Precise orbit determination
M06  High-precision clocks in receivers

Navigation, Positioning and its Applications
N01  Signal processing
N02  Signal propagation aspects
N03  Multi-constellation GNSS
N04  Sensors, hybridization and integrated navigation for science
N05  Precise positioning 
N06  Animal tracking

GNSS Science Transversal
T01   GNSS Big Data for science / scientific data archives
T02   Internet of Things Positioning for Science
T03   Scientific Payloads in GNSS satellites
T04   Supporting ground infrastructure (GNSS, SLR, ...)
T05   Disruptive technologies
T06   Cubesats, HAPS and UAVs for GNSS science
T07   Software receivers / low-cost SDR platforms
T08   Autonomous Vehicles for Science
T09   Space users and cis-lunar navigation
T10   GNSS science and education