Recordmaps by Mission

Mission Topex
MVA-Name topex_f_hf
Source GDR-F
Frequency 20

agc.00

Pos Size Scaling Unit Name Version Specific Description
1 2 -2 db agc Automatic Gain Control
20 Hz Ku-band On-Board Attenuator Gain Control (AGC) as provided in the original SDR, which includes temperature corrections.
Source: GDR-F
Original-Parameter: agc_20hz_ku
2 +2 -2 db agc_rms RMS of AGC
RMS of 20 Hz Ku-band AGC measurements. Only valid 20 Hz measurements are used to compute this element.
Source: GDR-F
Original-Parameter: agc_rms_ku

doppler.00

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m doppler Doppler Correction
Doppler correction to Ku-band range. Computed using orbit altitude rate (altitude_rate_mean_sea_surface).
Source: GDR-F
Original-Parameter: range_cor_doppler_ku

ebias.00

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m emb Sea State Bias
Computed using wind speed (wind_speed_alt) and significant waveheight (swh_ku). A sea state bias correction must be added (negative value) to the instrument range to correct this range measurement for sea state delays of the radar pulse. This element should not be used over land. Applicable to Ku-band MLE4 ranges.
Source: GDR-F
Original-Parameter: sea_state_bias_ku

instr.00

Pos Size Scaling Unit Name Version Specific Description
1 +4 - sec isec Integer Seconds Elapsed Since Epoch
[tai_utc_difference] is the difference between TAI and UTC reference time (seconds) for the first measurement of the data set. [leap_second] is the UTC time at which a leap second occurs in the data set, if any. After this UTC time, the tai_utc_difference is increased by 1 second.
Source: GDR-F
Original-Parameter: time_20hz
2 +4 -6 sec msec Microseconds, Fractional Part of isec
[tai_utc_difference] is the difference between TAI and UTC reference time (seconds) for the first measurement of the data set. [leap_second] is the UTC time at which a leap second occurs in the data set, if any. After this UTC time, the tai_utc_difference is increased by 1 second.
Source: GDR-F
Original-Parameter: time_20hz
3 +4 -3 m ralt Altimeter Range
20 Hz Ku-band MLE4 range. Net instrument range correction (net_instr_cor_range_ku) has been added.
Source: GDR-F
Original-Parameter: range_20hz_ku
4 +2 -3 m stdalt RMS of Altimeter Range
RMS of 20 Hz Ku-band MLE4 range measurements. Only valid 20 Hz measurements are used to compute this element.
Source: GDR-F
Original-Parameter: range_rms_ku
5 2 -2 m swh Significant Wave Height
20 Hz Ku-band MLE4 significant waveheight. Instrumental corrections are not required.
Source: GDR-F
Original-Parameter: swh_20hz_ku
6 +2 -2 m stdswh RMS of Significant Wave Height
RMS of 20 Hz Ku-band MLE4 significant waveheight measurements. Only valid 20 Hz measurements are used to compute this element.
Source: GDR-F
Original-Parameter: swh_rms_ku
7 +2 -2 db sigma0 Backscatter Coefficient
Sum of Ku-band AGC, MLE-4 retracked Ku-band echoes amplitude correction (including Ku-band point target response correction, given in net_instr_cor_sig0_ku), amplitude correction to account for satellite altitude, atmospheric attenuation (rad_atm_cor_sig0_ku), and constant Ku-band bias to align with original geophysical data record from side B.
Source: GDR-F
Original-Parameter: sig0_20hz_ku
8 +1 -1 m/s windsp Wind Speed
Sea surface wind speed.
Source: GDR-F
Original-Parameter: rad_wind_speed
9 +1 - - iflags Instrument Status and Quality Flags
Source: GDR-F
Original-Parameter: agc_20hz_ku, agc_rms_ku, alt_state_flag_oper, range_numval_ku, rain_flag,ice_flag
Flags:
1 : agc_20hz_ku in [32767,0] or agc_rms_ku in [32767,0] or agc_rms_ku/agc_20hz_ku > 0.1
2 : swh_ku in [32767,0] or swh_rms_ku in [32767,0] or swh_rms_ku/swh_ku > 0.1
4 : alt_state_flag_oper == 1 (0: SideA, 1: SideB)
8 : range_numval_ku < 12
16 : alt_state_flag_oper == 2 (0: Topex, 1: Poseidon)
64 : rain_flag != 0 or ice_flag != 0
128 : range_ku == nan or range_rms_ku == nan

instr.01

Pos Size Scaling Unit Name Version Specific Description
1 +4 - sec isec Integer Seconds Elapsed Since Epoch
[tai_utc_difference] is the difference between TAI and UTC reference time (seconds) for the first measurement of the data set. [leap_second] is the UTC time at which a leap second occurs in the data set, if any. After this UTC time, the tai_utc_difference is increased by 1 second.
Source: GDR-F
Original-Parameter: time_20hz
2 +4 -6 sec msec Microseconds, Fractional Part of isec
[tai_utc_difference] is the difference between TAI and UTC reference time (seconds) for the first measurement of the data set. [leap_second] is the UTC time at which a leap second occurs in the data set, if any. After this UTC time, the tai_utc_difference is increased by 1 second.
Source: GDR-F
Original-Parameter: time_20hz
3 +4 -3 m ralt Altimeter Range
20 Hz Ku-band MLE3 range. Net instrument range correction (net_instr_cor_range_ku_mle3) has been added.
Source: GDR-F
Original-Parameter: range_20hz_ku_mle3
4 +2 -3 m stdalt RMS of Altimeter Range
RMS of 20 Hz Ku-band MLE3 range measurements. Only valid 20 Hz measurements are used to compute this element.
Source: GDR-F
Original-Parameter: range_rms_ku_mle3
5 2 -2 m swh Significant Wave Height
20 Hz Ku-band MLE3 significant waveheight. Instrumental corrections are not required.
Source: GDR-F
Original-Parameter: swh_20hz_ku_mle3
6 +2 -2 m stdswh RMS of Significant Wave Height
RMS of 20 Hz Ku-band MLE3 significant waveheight measurements. Only valid 20 Hz measurements are used to compute this element.
Source: GDR-F
Original-Parameter: swh_rms_ku_mle3
7 +2 -2 db sigma0 Backscatter Coefficient
Sum of Ku-band AGC, MLE-3 retracked Ku-band echoes amplitude correction (including Ku-band point target response correction, given in net_instr_cor_sig0_ku_mle3), amplitude correction to account for satellite altitude, atmospheric attenuation (rad_atm_cor_sig0_ku), and constant Ku-band bias to align with original geophysical data record from side B.
Source: GDR-F
Original-Parameter: sig0_20hz_ku_mle3
8 +1 -1 m/s windsp Wind Speed
Sea surface wind speed.
Source: GDR-F
Original-Parameter: rad_wind_speed
9 +1 - - iflags Instrument Status and Quality Flags
Source: GDR-F
Original-Parameter: agc_20hz_ku, agc_rms_ku, alt_state_flag_oper, range_numval_ku_mle3, rain_flag,ice_flag
Flags:
1 : agc_20hz_ku in [32767,0] or agc_rms_ku in [32767,0] or agc_rms_ku/agc_20hz_ku > 0.1
2 : swh_ku_mle3 in [32767,0] or swh_rms_ku_mle3 in [32767,0] or swh_rms_ku_mle3/swh_ku_mle3 > 0.1
4 : alt_state_flag_oper == 1 (0: SideA, 1: SideB)
8 : range_numval_ku_mle3 < 12
16 : alt_state_flag_oper == 2 (0: Topex, 1: Poseidon)
64 : rain_flag != 0 or ice_flag != 0
128 : range_ku == nan or range_rms_ku_mle3 == nan

invbm.00

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m invb Inverse Barometer Effect
Computed at the altimeter time-tag from the interpolation of 2 meteorological fields that surround the altimeter time-tag. See TOPEX User Handbook.
Source: GDR-F
Original-Parameter: inv_bar_cor

ionos.00

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m ionos Ionospheric correction
No available for Poseidon (alt_state_flag_oper == 2)
An ionospheric correction must be added (negative value) to the instrument range to correct for ionospheric delays of the radar pulse. A calibration bias of -0.06945 m has been added to (range_ku + sea_state_bias_ku) - (range_c + sea_state_bias_c) before computing this correction.
Source: GDR-F
Original-Parameter: iono_cor_alt_ku

ionos.01

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m ionos Ionospheric correction
An ionosphere correction must be added (negative value) to the instrument range to correct for ionospheric delays of the radar pulse. This value is generated from Global Ionosphere Maps (GIM) and are only available from repeat cycle 48.
Source: GDR-F
Original-Parameter: iono_cor_gim_ku

orbit.00

Pos Size Scaling Unit Name Version Specific Description
1 +4 -6 deg glon Longitude
East longitude relative to Greenwich meridian.
Source: GDR-F
Original-Parameter: longitude_20hz
2 4 -6 deg glat Latitude
Positive latitude is North latitude, negative latitude is South latitude.
Source: GDR-F
Original-Parameter: latitude_20hz
3 +4 -3 m hsat Satellite Altitude
Altitude of satellite above the reference ellipsoid (GSFC POD solution).
Source: GDR-F
Original-Parameter: altitude_20hz
4 +1 - - oflags Orbit Status and Quality Flags
Source: GDR-F
Original-Parameter: depth_or_elevation, rad_surface_type_flag, alt_echo_type, surface_classification_flag, altitude
Flags:
2 : depth_or_elevation > -2000
4 : depth_or_elevation > -200
8 : rad_surface_type_flag != 0 || alt_echo_type != 1
16 : surface_classification_flag != 0
128 altitude == nan

tidee.00

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m etide Solid Earth Tide Correction
Calculated using Cartwright and Tayler tables and consisting of the second and third degree constituents. The permanent tide (zero frequency) is not included. See TOPEX User Handbook.
Source: GDR-F
Original-Parameter: solid_earth_tide
2 2 -3 m ptide Pole Tide Correction
Adopts Ries and Desai [2017] model for mean pole location. Xp = 55.0 + 1.677*DT, Yp = 320.5 + 3.460*DT in milliarcseconds with DT = years since 2000.0.
Source: GDR-F
Original-Parameter: pole_tide

tropd.00

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m dtrop Dry Tropospheric Correction
Computed at mean sea level at the altimeter time-tag from the interpolation of 2 meteorological fields that surround the altimeter time-tag. A dry tropospheric correction must be added (negative value) to the instrument range to correct this range measurement for dry tropospheric range delays of the radar pulse. See TOPEX User Handbook.
Source: GDR-F
Original-Parameter: model_dry_tropo_cor_zero_altitude

tropw.00

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m wtrop Wet Tropospheric Correction
Value must be added to altimeter range to correct for delay due to the wet troposphere.
Source: GDR-F
Original-Parameter: rad_wet_tropo_cor

tropw.01

Pos Size Scaling Unit Name Version Specific Description
1 2 -3 m wtrop Wet Tropospheric Correction
Computed at mean sea level at the altimeter time-tag from the interpolation of 2 ERA meteorological fields that surround the altimeter time-tag. A wet tropospheric correction must be added (negative value) to the instrument range to correct this range measurement for wet tropospheric range delays of the radar pulse. See TOPEX User Handbook.
Source: GDR-F
Original-Parameter: model_wet_tropo_cor_zero_altitude

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