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| This report is an archived publication and may contain dated technical, contact, and link information |
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Publication Number: FHWA-HRT-08-035 Date: March 2008 |
This chapter provides details on the data delivered for upload into the LTPP IMS database. Two tables were developed specifically to store data from this study: SMP_TDR_CALIBRATE and SMP_TDR_MOISTURE.
| Field | Comment |
|---|---|
| STATE_CODE | Numerical code for State or Province. |
| SHRP_ID | Test section identification number assigned by LTPP. |
| TDR_NO | TDR sensor number. |
| CAL_DRY_DENSITY | Retrieved from other LTPP tables or assumed. |
| SOURCE_DRY_DENSITY_TDR | Code indicating source of CAL_DRY_DENSITY. 1-SMP installation report 2-SMP installation report - I07 form 3-SMP installation report - S04 form 4-SMP installation report - I05 form 5-IMS table TST_ISD_MOIST 6-IMS table TST_SS08 7-IMS table INV_SUBGRADE 8-From Appendix C of "Analysis of Time Domain Reflectometry Data From LTPP Seasonal Monitoring Program Test Sections-Final Report" FHWA-RD-99-115 |
| CAL_DRY_DENSITY_ADJUSTMENT_METHOD | Code indicating type of adjustment made to CAL_DRY_DENSITY. 1-Adjustment based on vertical variation 2-Adjustment based on vertical variation and air volume |
| CAL_VOLUMETRIC_MOISTURE_CONTENT | Measured VMC from samples taken during installation. |
| CAL_SOIL_DIELECTRIC | Dielectric constant estimated from manual TDR trace taken at installation (from SMP Installation Report). |
| CAL_DIELECTRIC_SOLIDS | Computed using measured VMC and TDR trace taken during installation. This is used to calibrate the micromechanics equation to the specific TDR sensor for subsequent VMC computations. |
| CAL_DIELECTRIC_WATER | Computed using measured VMC and TDR trace taken during installation. This is used to calibrate the micromechanics equation to the specific TDR sensor for subsequent VMC computations. |
| CAL_DIELECTRIC_AIR | Computed using measured VMC and TDR trace taken during installation. This is used to calibrate the micromechanics equation to the specific TDR sensor for subsequent VMC computations. |
| CAL_SPECIFIC_GRAVITY | Computed using dry density and TDR trace taken during installation. This is used to calibrate the micromechanics equation to the specific TDR sensor for subsequent density computations. |
The SMP_TDR_MOISTURE table contains dielectric constant, moisture, conductivity, and reflectivity data estimated from automated TDR traces. A description of each field can be found in table 22.
| Field | Comment |
|---|---|
| STATE_CODE | Numerical code for State or Province. |
| SHRP_ID | Test section identification number assigned by LTPP. |
| SMP_DATE | Date TDR trace was obtained. |
| TDR_TIME | Time TDR trace was obtained. |
| TDR_NO | TDR sensor number. |
| TLE_BEGIN | Starting point of interval on TDR trace captured for use in the Transmission Line Equation. |
| TLE_END | Ending point of interval on TDR trace captured for use in the Transmission Line Equation. |
| SOIL_DIELECTRIC | Dielectric constant estimated from TDR trace (from SMP_TDR_AUTO). |
| SOIL_CONDUCTIVITY | Conductivity estimated from TDR trace (from SMP_TDR_AUTO). |
| SOIL_REFLECTIVITY | Reflectivity estimated from TDR trace (from SMP_TDR_AUTO). |
| DRY_DENSITY | Dry density estimated from SOIL_DIELECTRIC and calibrated micromechanics equation. |
| VOLUMETRIC_MOISTURE_CONTENT | VMC estimated from SOIL_DIELECTRIC and calibrated micromechanics equation. |
| GRAVIMETRIC_MOISTURE_CONTENT | GMC estimated from VMC and DRY_DENSITY. |
| TDR_COMPUTATION_COMMENT_CODE | Codes to describe traces that could not be interpreted. 1-TDR trace uninterpretable due to lack of negative slope 2-Questionable data due to low dry density value 3-Calibration data from installation activities are unavailable 4-Outlier data based on time series analysis 5-Volumetric moisture content was in transition zone and was adjusted |
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