tokens: ['the', 'following', 'steps', '', 'Computation', 'of', 'satellite', 'locations', 'at', 'time', 'of', 'transmission', 'using', 'the', 'ephemeris', 'parameters', 'and', 'user', 'algorithms', 'defined', 'in', 'the', 'relevant', 'ICD', 'of', 'the', 'particular', 'GNSS', 'The', 'satellite', 'locations', 'are', 'transformed', 'into', 'WGS', 'reference', 'frame', 'if', 'needed', '', 'Computation', 'of', 'clock', 'correction', 'parameters', 'using', 'the', 'parameters', 'and', 'algorithms', 'as', 'defined', 'in', 'the', 'relevant', 'ICD', 'of', 'the', 'particular', 'GNSS', '', 'Computation', 'of', 'atmospheric', 'delay', 'corrections', 'using', 'the', 'parameters', 'and', 'algorithms', 'defined', 'in', 'the', 'relevant', 'ICD', 'of', 'the', 'particular', 'GNSS', 'for', 'the', 'ionospheric', 'delay', 'and', 'using', 'the', 'Gupta', 'model', 'in', 'reference', '', 'p', '', 'equation', '', 'for', 'the', 'tropospheric', 'delay', 'For', 'GNSSs', 'which', 'do', 'not', 'natively', 'provide', 'ionospheric', 'correction', 'models', 'eg', 'GLONASS', 'the', 'ionospheric', 'delay', 'is', 'determined', 'using', 'the', 'available', 'ionospheric', 'model', 'adapted', 'to', 'the', 'particular', 'GNSS', 'frequency', '', 'The', 'WLS', 'position', 'solution', 'starts', 'with', 'an', 'initial', 'estimate', 'of', 'the', 'user', 'state', 'position', 'and', 'clock', 'offset', 'The', 'Reference', 'Location', 'is', 'used']