Calculate Survey Database QC Stats

Use the Calculate Survey Database QC Stats option (Geosoft.uxo.gxnet.dll(Geosoft.GX.UXO.UxaSurveyDataQc;Run)*) from the AGC Static Data > Sensor Tests and QC Tools menu to analyze the survey data and generate quality control (QC) statistics. The data that fail the quality control are identified using a series of mask channels and should be reviewed. The mask channels can then be used to create plots (e.g., Decay Display QC) of the failed data.

Calculate Survey Database QC Stats dialog options

Master Database
Master database prefix	Select the optional master database prefix. Script Parameter: UXANALYZE.MASTER_IMPORT_DBPREFIX
Group	Select the group in the master database. Default group name is FlagList. Script Parameter: UXANALYZE.MASTER_GROUP
Databases
Prefix	Specify the survey databases prefix. If present in the selected folder, the database prefixes for the following data types are available: SAM, SBG, SBR, SFR, SFT, SMD, SRB, SQC, STP, SXM. Script Parameter:UXANALYZE.DATAQC_PREFIX
Target group	Select the target group. Script Parameter:UXANALYZE.TARGETGROUP
Mask channel	Select the mask channel. Default: UXA_Mask Script Parameter:UXANALYZE.TARGETMASK
QC mask channel	Select the QC mask channel. Default: UXA_Mask_QC The QC mask channel will be set to DUMMY if any of the QC checks fail. Script Parameter:UXANALYZE.TARGETMASK2
Data channel	Select the data channel. Default: UXA_Data_Norm Script Parameter:UXANALYZE._SENCHAN
GPS fix quality	Select the GPS fix quality, which can be from 0 to 8. Default value is 4. For information on the GPS fix quality test, see the Application Notes below. Script Parameter:UXANALYZE.GPSFIXQ
Output
Output file name	Specify the output base file name, which is used to generate the output plot and text (CSV) file names. The default name is based on the acquisition date and time of the most recent measurement in the survey database. The output files are saved in the "..\UXANALYZE_wrk\dataqc_plots" folder. For information on the output files, see the Application Notes below. Script Parameter:UXANALYZE.DATAQC_OUTPUTNAME

Application Notes

The following tests are carried out on the survey data:

• Flat-line Receiver (RX) data
• Saturated Receiver (RX) data
• Transmitter (TX) Current
• GPS Position fix quality
• Inertial Measurement Unit (IMU)
• Sensor Array vs Flag location

The QC mask channel in the Target database is updated for flags that pass all QC tests (1) and for those that fail one or more tests (dummy). You should review these flags to verify the results. For each of the tests, a mask channel is created in the Target database to indicate whether that measurement fails (1) or passes (dummy) the QC metric. In addition, mask channels are created in the Data database for Flat-lined RX, Saturated RX or TX Current tests to identify specific TX-RX combinations that fail the QC metric.

As the QC mask channel may be updated by other QC tools, an additional mask channel, UXA_QC_Data, is created with the same values as the QC mask channel to preserve the summary results of the Survey QC.

The results are also provided in a CSV file and a map of the flag locations.

Check Flat-lined RX Data

For the selected measurements to test for flat-lined receiver data:

1. Calculate the log of the absolute value of the sensor transient data.

2. Calculate the difference between successive gates in the transient data.

3. For a moving window along the transient data (array), determine the maximum successive difference. The length of the window is 0.25 (nSuccessiveDiffMultiplier) of the number of gates (UXA_Windows).

4. Identify measurements and Tx-Rx pairs where the maximum difference within any window is less than 0.02 (lowerBound).

5. The results are saved in the UXA_FLATLINED_FLAG channel in the Target and Data databases.

6. The flat-lined receiver data thresholds (flatLinedRxData) are defined in the configuration file (uxa.config).

Check Saturated RX Data

For the selected measurements to test for saturated receiver data:

• Multiply the data by the maximum current.

• Identify measurements and Tx-Rx pairs where the absolute data value for the first valid time (UXA_GateFirstValidTime) or later (i.e., the low gate or higher) is greater than the saturation threshold (UXA_ReceiverSaturationThreshold).

  For legacy MetalMapper (original) data, the current is not saved; therefore, we identify flags where the sensor data is outside ±800 for the low gate (8) or higher.

The result is saved in the UXA_SATURATED_FLAG channel in the Target and Data databases.

Check TX Current

For the selected measurements, find the peak current and identify when it is less than the current threshold (UXA_TransmissionCurrentThreshold).

The result is saved into the UXA-CURRENT_FLAG channel in the Target and Data databases.

Check GPS Position Fix Quality

For the selected measurements, calculate the median and standard deviation of the measurement positions.
Identify any measurements, where:

• The GPSFIXQ is not equal to the value entered; default value is 4, typically a Real Time Kinematic (RTK) fix.
• A flag position is outside of the median ± the range, where the range is the larger of 10000 (distanceMin)  or 3 (multiplier) times the standard deviation of the positions.

The result is saved in the UXA_GPS_FLAG channel in the Target database.

The GPS Position fix quality thresholds (gps) are defined in the configuration file (uxa.config).

Check IMU (Inertial Measurement Unit)

For the selected measurements, calculate the range of the pitch, roll and yaw channels.

Identify any measurement, where:

• The Pitch is greater than ±30 or
• The Roll is greater than ±30 or
• The Yaw is out range, either 0 to 360 or -180 to 180, or
• The Pitch, Roll and Yaw are all equal to 0 or

• Successive measurements (in time) have the same values for Pitch, Roll and Yaw.

The result is saved in the UXA_IMU_FLAG channel in the Target database.

IMU data thresholds (IMU) are defined in the configuration file (uxa.config).

Check Array vs Flag location

If the flag position channels exist, (i.e., UXA FLAG X and UXA FLAG Y), identify the measurement where the distance between the sensor array position and flag position is greater than 0.4.

The result is saved in the UXA_FLAG_ARRAY_FLAG channel in the Target database.

The Array-Flag location threshold (flagArrayDiff) is defined in the configuration file (uxa.config).

Master Database

In the master database (if selected), the channel UXA_QC_Data is created (if it does not exist).

The channel is populated based on the content of UXA_QC_Data channel in the target database: it will be set to dummy if all the records in the target database with the same geo ID and flag ID are dummy.

Output Files

The Calculate Survey Database QC Stats dialog saves the QC results into the target and data databases along with a summary plot and a summary text file. The files are named SurveyDataQC_YYYYMMDD_hhmm, where YYYYMMDD and hhmm are acquisition data and time of the most recent measurement. The output plot and text files are saved in the "...\UXANALYZE_wrk\dataqc_plots" folder.

The output plot (PNG) file includes:

• A plan map of the data showing the measurement locations, with the locations that fail the QC tests highlighted in red.
• A summary table of the flags that failed the QC tests, along with which test failed.

The output text (CSV) file includes:

• All the flags, with the failed ones at the top of the file.
• The overall pass/fail status of the flag and the results of the individual tests.

UX-Analyze Configuration File

The configuration file contains various default or standard settings for the tools. It is not recommended that you edit this file unless directed by Support. The file "uxa.config", is located in the "C:\Program Files\Geosoft\Desktop Applications \etc" folder: The default QC metrics can be found in the UX-Anlyze configuration file, see the surveyQcStats section as shown below:

<surveyQcStats>   <gps multiplier="3" distanceMin="10000" />   <imu pitchMin="-30" pitchMax="30" rollMin="-30" rollMax="30" yawMin="-180" yawMax="360" multiplier="3" />   <flagArrayDiff max="0.4" />   <txCurrent minMultipler="0.98" />   <flatLinedRxData lowerBound="0.02" nSuccessiveDiffMultiplier="0.25" /> </surveyQcStats>