GNSS measurements at a pair of sites (clear-sky and forested) used to calculate GNSS-VOD

This readme documents the raw and processed GNSS data used in Humphrey & Frankenberg (2023), Biogeosciences.

The preprint can be accessed at: https://doi.org/10.5194/bg-2022-84

For information regarding the experiment, site location, and sensor configuration, please refer to the published (final) paper.

This archive contains both raw and processed continuous GNSS measurements taken by two Septentrio PolaRx5e receivers over a period of 8 months at 15 second intervals (from GPS, Galileo, GLONASS and BeiDou, at all available frequencies). The data files are stored with the following structure:

- POLAR1_Roof  (clear-sky site)

-- bnx

--- SEPT[dayofyear].20.bnx (raw daily BINEX GNSS files)

-- processed

--- azi

---- SEPT[dayofyear][a-x].azi (calculated azimuth information for tracked satellites)

--- ele

---- SEPT[dayofyear][a-x].ele (calculated elevation information for tracked satellites)

--- sn1

---- SEPT[dayofyear][a-x].sn1 (measured carrier-to-noise power density (C/N0) information for tracked satellites)

- POLAR2_Forest   (subcanopy site)

-- bnx

--- SEPT[dayofyear][a-x].20.bnx (raw hourly BINEX GNSS files)

-- processed

--- azi

---- SEPT[dayofyear][a-x].azi (calculated azimuth information for tracked satellites)

--- ele

---- SEPT[dayofyear][a-x].ele (calculated elevation information for tracked satellites)

--- sn1

---- SEPT[dayofyear][a-x].sn1 (measured carrier-to-noise power density (C/N0) information for tracked satellites)

Raw bnx data was converted using the teqc software (2019-02-25 final release), with the following command (applied to each file)

$ teqc +qc +plot ++rx_state rx_state path_to_input_file_here

Teqc produces a large number of quality-checked processed files, among which the '.azi' '.ele' and '.sn1' files used in the paper.