Documentation
This site monitors the performance of CryoSat-2 Level-2 products by mapping and summarising selected product parameters for every 30-day data take, for each ESA processing baseline.
Input Products
- L2 GDR-A: the global Level-2 geophysical data record, containing the 20 Hz measurements of all acquisition modes (LRM, SAR and SARin).
- L2i: intermediate Level-2 products, organised by acquisition mode, containing additional specialised parameters.
The product baseline is identified by the baseline letter in the product file name
(ie CS_OFFL_SIR_GDR_2__20260801T002509_20260801T020423_F001.nc is baseline F,
version 001). Results of each baseline are produced and shown separately. When the same granule
is available more than once for a baseline, the highest version is used.
The Data Availability page shows the number of files of each product per acquisition day over the most recent 30 days of data, and the latest data received.
Data Takes (Cycles)
Results are organised by fixed 30-day data takes of CryoSat-2 rather than by calendar month. Cycle 1 starts at 00:00 UTC on 18-Oct-2010, the start of the operational phase, and cycle n covers the 30 days from 18-Oct-2010 + 30 × (n−1) days. Each measurement is assigned to a cycle by its time stamp, so a product spanning a cycle boundary contributes to both cycles. Product time stamps can be TAI rather than UTC, so measurements within about 37 seconds of a cycle boundary may be assigned to the neighbouring cycle. See the list of cycles.
GDR-A products become available about 35 days after acquisition, so recent cycles are first processed with partial data and reprocessed as further products become available. The coverage of each cycle (the number of its days covered by the input products) is shown with the results, and cycles covering less than 95% of their days are marked as partial.
Areas
- Global: all measurements.
- North Polar: measurements located north of 60°N.
- South Polar: measurements located south of 60°S.
Measurement locations are taken from each variable's coordinates, which are the nadir location or the estimated echo location (point of closest approach, POCA) depending on the variable and product baseline.
Maps
Maps show the parameter at each measurement location of the cycle, with histograms of the values and a map of the locations of missing values. To keep map production practical, maps of more than 2 million valid measurements show a regular subsample of the measurements along track (the fraction plotted is noted on the map); the statistics printed on the maps, and all the statistics on this site, use every measurement.
Some parameters (ie radar freeboard) also have gridded maps of the polar regions: the valid measurements of the cycle are gridded into the cells of a polar stereographic grid (ie 10 km cells, EPSG:3413 in the north and EPSG:3031 in the south), and a statistic of the measurements in each cell (median, mean, maximum, standard deviation or count) is mapped. The statistics of a gridded map are those of its cell values.
Statistics
- Flag parameters (ie acquisition mode, surface type): the percentage of each flag value, calculated from the valid (non-fill) values in the area.
- Physical parameters (ie backscatter): the mean, median, standard deviation (population), root mean square (RMS), minimum and maximum of the valid values in the area.
- Crossovers: single cycle crossover height differences (ascending minus descending) over the Antarctic and Greenland ice sheets, per acquisition mode and retracker. The number of crossovers, and statistics of the differences within 5 m (one crossover per pair of passes), with maps of the mean difference within 20 km of each 10 km grid cell.
- Quality flags: the percentage of records with each bit set, per acquisition mode and per mode over a surface type of the surface type mask (LRM over ice, land and ocean, SARin over ice and land, SAR over ocean), as in the CryoSat-2 quality reports.
- For every selection the number of measurements (Records) and the number of valid values (Valid) are also given.
Statistics of all cycles are shown as trends on each parameter page and can be downloaded as CSV files.
Monitored Parameters
| Parameter | Product | Variables | Type | Selections |
|---|---|---|---|---|
| SIRAL Acquisition Mode | GDR-A | flag_instr_mode_op_20_ku |
Flag | Global, North Polar (>60N), South Polar (<60S) |
| Surface Type | GDR-A | surf_type_20_ku |
Flag | Global, North Polar (>60N), South Polar (<60S) |
| Surface Height | GDR-A | height_1_20_ku, height_2_20_ku, height_3_20_ku |
Physical (m) |
Global, North Polar (>60N), South Polar (<60S) per retracker: Retracker 1, Retracker 2, Retracker 3 per acquisition mode |
| Backscatter (Sigma0) | GDR-A | sig0_1_20_ku, sig0_2_20_ku, sig0_3_20_ku |
Physical (dB) |
Global, North Polar (>60N), South Polar (<60S) per retracker: Retracker 1, Retracker 2, Retracker 3 per acquisition mode |
| Quality Flags | GDR-A | flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku, flag_prod_status_20_ku |
Flag |
Global, North Polar (>60N), South Polar (<60S) per flag bit: Record degraded, Orbit error, Orbit discontinuity, Height error (retracker 1), Height error (retracker 2), Height error (retracker 3), Sea ice height error, SSHA interpolation error, Calibration warning, Backscatter error (retracker 1), Backscatter error (retracker 2), Backscatter error (retracker 3), Freeboard error, Peakiness error, Surface class: ocean, Surface class: lead, Surface class: sea ice, Surface class: undefined, SARin RX 1 error, SARin RX 2 error, SARin side redundant, Surface model unavailable, Mispointing error, Delta time error, SARin bad velocity, SARin out of range, SARin bad baseline, SARin height ambiguous, LRM slope model invalid, SARin height unwrap, SARin off-nadir lead per acquisition mode |
| Geophysical Corrections | GDR-A | mod_dry_tropo_cor_01, mod_wet_tropo_cor_01, inv_bar_cor_01, hf_fluct_total_cor_01, iono_cor_01, iono_cor_gim_01, sea_state_bias_01_ku, ocean_tide_01, ocean_tide_eq_01, load_tide_01, solid_earth_tide_01, pole_tide_01 |
Physical (m) |
Global, North Polar (>60N), South Polar (<60S) per correction: Dry troposphere (model), Wet troposphere (model), Inverse barometer, Dynamic atmosphere (DAC), Ionosphere (model), Ionosphere (GIM), Sea state bias, Ocean tide, Long period tide, Ocean loading tide, Solid earth tide, Geocentric pole tide |
| Mispointing Angle | GDR-A | mispointing_angle, off_nadir_roll_angle_str_01, off_nadir_pitch_angle_str_01, off_nadir_yaw_angle_str_01 |
Physical (mdeg) |
Global, North Polar (>60N), South Polar (<60S) per angle: Mispointing, Roll, Pitch, Yaw per acquisition mode |
| Waveform Peakiness | GDR-A | peakiness_20_ku |
Physical |
Global, North Polar (>60N), South Polar (<60S) per acquisition mode |
| Sea Surface Height Anomaly | GDR-A | ssha_interp_20_ku |
Physical (m) |
Global, North Polar (>60N), South Polar (<60S) per acquisition mode |
| Snow Depth | GDR-A | snow_depth_01 |
Physical (m) | Global, North Polar (>60N), South Polar (<60S) |
| Snow Density | GDR-A | snow_density_01 |
Physical (kg/m^3) | Global, North Polar (>60N), South Polar (<60S) |
| Sea Ice Concentration | GDR-A | sea_ice_concentration_01 |
Physical (%) | Global, North Polar (>60N), South Polar (<60S) |
| Radar Freeboard | GDR-A | radar_freeboard_20_ku, radar_freeboard_20_ku |
Physical (m) |
Global, North Polar (>60N), South Polar (<60S) per measurements: Freeboard error not set, All measurements per acquisition mode |
| Sea Ice Freeboard | GDR-A | sea_ice_freeboard_20_ku |
Physical (m) |
Global, North Polar (>60N), South Polar (<60S) per acquisition mode |
| Sea Ice Thickness | GDR-A | sea_ice_thickness_20_ku |
Physical (m) |
Global, North Polar (>60N), South Polar (<60S) per acquisition mode |
| Crossover Height Differences | GDR-A | height_1_20_ku, height_2_20_ku, height_3_20_ku |
Physical (m) |
Antarctic Ice Sheet, Greenland Ice Sheet per retracker: Retracker 1, Retracker 2, Retracker 3 per acquisition mode |
| Retracker Range Correction | L2I | retracker_1_cor_20_ku, retracker_2_cor_20_ku, retracker_3_cor_20_ku |
Physical (m) |
Global, North Polar (>60N), South Polar (<60S) per retracker: Retracker 1, Retracker 2, Retracker 3 per acquisition mode |
| Retracker Flags | L2I | flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku, flag_retracker_20_ku |
Flag |
Global, North Polar (>60N), South Polar (<60S) per flag bit: Retracker 1 failure, Retracker 2 failure, Retracker 3 failure, Sea ice retracker failure, Poor phase fit, Poor power fit, FDM / OCOG failure, Fit failed, SARin low coherence, SARin interpolation failure, Abnormal beam behaviour parameter, Out of range, Bad leading edge, Low variance, High noise, High peakiness, Low peakiness, Low power per acquisition mode |
| Discriminated Surface Type | L2I | flag_surf_type_class_20_ku, flag_surf_type_class_20_ku, flag_surf_type_class_20_ku, flag_surf_type_class_20_ku, flag_surf_type_class_20_ku, flag_surf_type_class_20_ku, flag_surf_type_class_20_ku, flag_surf_type_class_20_ku, flag_surf_type_class_20_ku |
Flag |
Global, North Polar (>60N), South Polar (<60S) per surface class: LRM ocean, LRM land ice, LRM undefined, SARin valid, SARin undefined, Sea ice discrimination: ocean, Sea ice discrimination: sea ice, Sea ice discrimination: lead, Sea ice discrimination: undefined per acquisition mode |
| SARin Discriminator Parameters | L2I | sarin_output_1_20_ku, sarin_output_2_20_ku, sarin_output_3_20_ku, sarin_output_4_20_ku, sarin_output_5_20_ku, sarin_output_6_20_ku, sarin_output_7_20_ku, sarin_output_8_20_ku, sarin_output_9_20_ku, sarin_output_10_20_ku |
Physical |
Global, North Polar (>60N), South Polar (<60S) per parameter: Total power, Maximum power, Mean power, Bin of maximum power, Bin of half maximum power, Maximum coherence, Bin of maximum coherence, First power bin, Last power bin, Sea ice peakiness |
| SARin Ambiguity Warning | L2I | flag_sarin_ambiguity_warning_20_ku |
Flag | Global, North Polar (>60N), South Polar (<60S) |
| Stack Beam Behaviour | L2I | stack_std_20_ku, stack_centre_20_ku, stack_scaled_amplitude_20_ku, stack_skewness_20_ku, stack_kurtosis_20_ku, stack_peakiness_20_ku, stack_std_angle_20_ku, stack_centre_angle_20_ku, stack_centre_look_angle_20_ku, stack_gaussian_fitting_residuals_20_ku, stack_number_before_weighting_20_ku, stack_number_after_weighting_20_ku |
Physical |
Global, North Polar (>60N), South Polar (<60S) per stack parameter: Standard deviation, Centre, Scaled amplitude, Skewness, Kurtosis, Peakiness, Standard deviation (angle), Centre (boresight angle), Centre (look angle), Fit residuals, Beams before weighting, Beams after weighting per acquisition mode |
| Doppler Range Correction | L2I | dop_cor_20_ku, slope_dop_cor_20_ku |
Physical (m) |
Global, North Polar (>60N), South Polar (<60S) per correction: Doppler, Slope Doppler (LRM) per acquisition mode |
| LRM Slope Correction Attitude | L2I | offset_attitude_20_ku |
Physical (rad) | Global, North Polar (>60N), South Polar (<60S) |
Results generated 12-Oct-2026 01:12 UTC by the CSQA processing software version 1.0.0.