DOI: 10.5061/dryad.ghx3ffbx3
title: Exploring the impact of varied background on quantification of soil carbon content using microwave and millimeter wave signal reflectance

description: The quantification of soil carbon content is paramount to the advancement
 of soil carbon management practices, serving as the bedrock for the
 development and implementation of various carbon-negative and
 carbon-neutral technologies. These technologies are crucial in the battle
 against climate change and in enhancing soil health to boost agricultural
 productivity.  Therefore, we employ an innovative sensor
 technology comprised of a compact array, including 18 pairs of radar
 transmitters (TX) and receivers (RX) within a microwave radar array
 sensor, alongside a configuration of 20 TX and 20 RX pairs in a millimeter
 wave radar array sensor. For this kind of setup to work, the sensors need
 to be carefully tested to make sure they can capture changes in the
 soil's carbon content over time and space. This dataset presents an
 exhaustive series of raw data aimed at evaluating the efficacy of these
 two sensor technologies in detecting soil carbon content. A distinctive
 aspect of this study is the examination of sensor performance across four
 divergent backgrounds—glass, metal, sponge, and wood surfaces—to ascertain
 the influence of background material on radar wave reflectance and,
 consequently, measurement accuracy. Furthermore, the investigation extends
 to the analysis of sensing distance as a critical parameter for
 classification accuracy, with the microwave radar array sensor tested
 across distances ranging from 1 inch to 4 inches and the millimeter wave
 radar sensor evaluated at intervals of 2.5 inches, 5 inches, 7.5 inches,
 and 10 inches. By providing a comprehensive dataset on the performance
 evaluation of cutting-edge sensor technologies, this study aims to
 facilitate further advancements in the field of soil carbon management,
 ultimately supporting the global effort to combat climate change through
 innovative and sustainable agricultural practices.
description: Data Collection Microwave
 Sensor: <strong>Frequency and
 Sampling:</strong> The microwave sensor operated at a transmission
 frequency of 109.2 GHz, with each sample undergoing 20 iterations of data
 collection to mitigate random noise interference. 
 <strong>Antenna Configuration:</strong> The sensor
 configuration included 4 transmitters and 14 receivers, yielding 40 unique
 antenna pair combinations for comprehensive signal capture. The antenna
 pair combinations are in the readme file. 
 <strong>Signal Features:</strong> Each signal acquisition
 resulted in 8192 distinct signal features, facilitating detailed
 analysis. Millimeter Wave
 Sensor: <strong>Frequency Range and
 Sampling:</strong> The millimeter wave sensor’s operational
 frequency spanned from 62 GHz to 69 GHz, adopting an identical sampling
 strategy (20 times per sample) to ensure consistency in error
 reduction. <strong>Resolution and Sampling
 Points:</strong> Across the specified frequency range, 150 sampling
 points were established, with a resolution bandwidth (RBW) of 100 kHz
 chosen to balance sweep time and noise reduction. 
 <strong>Antenna and Resolution Profiles:</strong> The sensor
 comprised 20 transmitters and 20 receivers, with data collected under
 three resolution profiles (high, medium, and low) utilizing configurations
 of 4, 10, and all 20 transmitters, respectively. 
 <strong>Signal Features:</strong> The millimeter wave sensor
 captured 1024 features per antenna pair, enabling precise soil carbon
 content analysis. Sample Preparation and
 Testing Environment: <strong>Soil
 and Biochar Mixture:</strong> Samples consisted of soil collected
 from almond tree fields, cleared of coarse matter like stones, and mixed
 with biochar produced from 100% pinewood. The mixtures varied in biochar
 content across six classes, ranging from 0% to 100%. 
 <strong>Backgrounds and Sensing Distance:</strong> Data
 collection was conducted against four different backgrounds (glass, metal,
 sponge, and wood) to assess the impact of environmental interference on
 signal accuracy. The microwave sensor testing distances spanned from 1 to
 4 inches, while the millimeter wave sensor was evaluated at distances of
 2.5, 5, 7.5, and 10 inches from the sample.
description: # Exploring the impact of varied background on quantification of soil
 carbon content using microwave and millimeter wave signal reflectance ##
 Reference Information Authors: Di An, Patrick Zhang, YangQuan Chen Data
 Created: 04/08/2024 Data Modified: 04/08/2024 Suggested Citations:
 Dataset: An, Di; Zhang, Patrick; Chen, YangQuan (2024), Exploring the
 Impact of Varied Background on Quantification of Soil Carbon Content Using
 Microwave and Millimeter Wave Signal Reflectance, Dryad,
 [https://10.5061/dryad.ghx3ffbx3](https://10.5061/dryad.ghx3ffbx3)
 Corresponding publication: TBD ## Data and File Overview There are total
 16 datasets, where 4 for microwave and 12 for millimeter wave,
 respectively. The name meaning as follows: "glass_table",
 "metal_table", "sponge_table", "wood_table"
 = microwave sensing soil carbon content varied background such as glass,
 metal, sponge, and wood. "high_glass", "med_glass",
 "low_glass" = three different resolutions from high, medium and
 low profile of millimeter wave sensing results under glass background.
 "high_metal", "med_metal", "low_metal" =
 three different resolution from high, medium and low profile of millimeter
 wave sensing results under metal background. "high_sponge",
 "med_sponge", "low_sponge" = three different
 resolution from high, medium and low profile of millimeter wave sensing
 results under sponge background. "high_wood",
 "med_wood", "low_wood" = three different resolution
 from high, medium and low profile of millimeter wave sensing results under
 wood background. Microwave 40 antenna pairs combination information: |
 Antenna Pairs | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | | ------------- |
 ----- | ---- | ----- | ----- | ---- | ---- | ----- | ----- | ----- | -----
 | | Tx, Rx | 1,2 | 1,3 | 1,6 | 1,7 | 1,10 | 1,11 | 1,14 | 1,15 | 1,4 | 1,8
 | | Antenna Pairs | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | |
 Tx, Rx | 1,12 | 1,16 | 1,18 | 17,2 | 17,3 | 17,6 | 17,7 | 17,10 | 17,11 |
 17,14 | | Antenna Pairs | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30
 | | Tx, Rx | 17,15 | 17,8 | 17,12 | 17,16 | 4,2 | 4,3 | 4,6 | 4,7 | 4,10 |
 4,11 | | Antenna Pairs | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
 | Tx, Rx | 4,14 | 4,15 | 18,2 | 18,3 | 18,6 | 18,7 | 18,10 | 18,11 | 18,14
 | 18,15 | ### Setup * Unpacking instructions: N/A * Relationships between
 files/folders: they are in different experiments sections * Recommended
 software/tools: &gt; Matlab 2020 # File/Folder Details-Microwave ##
 Details for: glass\_table.mat * Description: This is for classifying
 different amount of soil and biochar mixture under glass background using
 high resolution profile and 40 antenna pair combination of microwave
 sensor. * Format(s): .mat * Size(s): 1,175,343 KB * Dimensions: * Data:
 4800 rows x 8192 cols * label: 4800 rows x 1 col * Variables: * glass_1in:
 raw data, using high resolution profile to sense mixture at 1 inch height
 of the sample. * glass_2in: raw data, using high resolution profile to
 sense mixture at 2 inch height of the sample. * glass_3in: raw data, using
 high resolution profile to sense mixture at 3 inch height of the sample. *
 glass_4in: raw data, using high resolution profile to sense mixture at 4
 inch height of the sample. * labelCategorical: Total 6 classes, each label
 has 20 samples, thus for one antenna pair combination it has 120 labels,
 therefore, it has 4800 labels in total. label '1-1' means first
 antenna pair combination with first soil and biochar mixture. label
 '1-2' it means first antenna pair combination with second soil
 and biochar mixture. label '2-1' means second antenna pair
 combination with first soil and biochar mixture, and so the rest labels
 on. ## Details for: metal\_table.mat * Description: This is for
 classifying different amount of soil and biochar mixture under metal
 background using high resolution profile and 40 antenna pair combination
 of microwave sensor. * Format(s): .mat * Size(s): 1,174,335 KB *
 Dimensions: * Data: 4800 rows x 8192 cols * label: 4800 rows x 1 col *
 Variables: * metal_1in: raw data, using high resolution profile to sense
 mixture at 1 inch height of the sample. * metal_2in: raw data, using high
 resolution profile to sense mixture at 2 inch height of the sample. *
 metal_3in: raw data, using high resolution profile to sense mixture at 3
 inch height of the sample. * metal_4in: raw data, using high resolution
 profile to sense mixture at 4 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, thus for one
 antenna pair combination it has 120 labels, therefore, it has 4800 labels
 in total. label '1-1' means first antenna pair combination with
 first soil and biochar mixture. label '1-2' it means first
 antenna pair combination with second soil and biochar mixture. label
 '2-1' means second antenna pair combination with first soil and
 biochar mixture, and so the rest labels on. ## Details for:
 sponge\_table.mat * Description: This is for classifying different amount
 of soil and biochar mixture under sponge background using high resolution
 profile and 40 antenna pair combination of microwave sensor. * Format(s):
 .mat * Size(s): 1,178,021 KB * Dimensions: * Data: 4800 rows x 8192 cols *
 label: 4800 rows x 1 col * Variables: * sponge_1in: raw data, using high
 resolution profile to sense mixture at 1 inch height of the sample. *
 sponge_2in: raw data, using high resolution profile to sense mixture at 2
 inch height of the sample. * sponge_3in: raw data, using high resolution
 profile to sense mixture at 3 inch height of the sample. * sponge_4in: raw
 data, using high resolution profile to sense mixture at 4 inch height of
 the sample. * labelCategorical: Total 6 classes, each label has 20
 samples, thus for one antenna pair combination it has 120 labels,
 therefore, it has 4800 labels in total. label '1-1' means first
 antenna pair combination with first soil and biochar mixture. label
 '1-2' it means first antenna pair combination with second soil
 and biochar mixture. label '2-1' means second antenna pair
 combination with first soil and biochar mixture, and so the rest labels
 on. ## Details for: wood\_table.mat * Description: This is for classifying
 different amount of soil and biochar mixture under wood background using
 high resolution profile and 40 antenna pair combination of microwave
 sensor. * Format(s): .mat * Size(s): 1,177,338 KB * Dimensions: * Data:
 4800 rows x 8192 cols * label: 4800 rows x 1 col * Variables: * wood_1in:
 raw data, using high resolution profile to sense mixture at 1 inch height
 of the sample. * wood_2in: raw data, using high resolution profile to
 sense mixture at 2 inch height of the sample. * wood_3in: raw data, using
 high resolution profile to sense mixture at 3 inch height of the sample. *
 wood_4in: raw data, using high resolution profile to sense mixture at 4
 inch height of the sample. * labelCategorical: Total 6 classes, each label
 has 20 samples, thus for one antenna pair combination it has 120 labels,
 therefore, it has 4800 labels in total. label '1-1' means first
 antenna pair combination with first soil and biochar mixture. label
 '1-2' it means first antenna pair combination with second soil
 and biochar mixture. label '2-1' means second antenna pair
 combination with first soil and biochar mixture, and so the rest labels
 on. # File/Folder Details-Millimeterwave ## Details for: high\_glass.mat *
 Description: This is for classifying different amount of soil and biochar
 mixture under glass background using high resolution profile millimeter
 wave sensor. * Format(s): .mat * Size(s): 3,707 KB * Dimensions: * Data:
 120 rows x 1024 cols * label: 120 rows x 1 cols * Variables: * high_25in:
 using high resolution profile to sense mixture at 2.5 inch height of the
 sample. * high_50in: using high resolution profile to sense mixture at 5.0
 inch height of the sample. * high_75in: using high resolution profile to
 sense mixture at 7.5 inch height of the sample. * high_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: high\_metal.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 metal background using high resolution profile of millimeter wave sensor.
 * Format(s): .mat * Size(s): 3,709 KB * Dimensions: * Data: 120 rows x
 1024 cols * label: 120 rows x 1 cols * Variables: * high_25in: using high
 resolution profile to sense mixture at 2.5 inch height of the sample. *
 high_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * high_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * high_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: high\_sponge.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 sponge background using high resolution profile of millimeter wave sensor.
 * Format(s): .mat * Size(s): 3,708 KB * Dimensions: * Data: 120 rows x
 1024 cols * label: 120 rows x 1 cols * Variables: * high_25in: using high
 resolution profile to sense mixture at 2.5 inch height of the sample. *
 high_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * high_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * high_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: high\_wood.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 wood background using high resolution profile of millimeter wave sensor. *
 Format(s): .mat * Size(s): 3,708 KB * Dimensions: * Data: 120 rows x 1024
 cols * label: 120 rows x 1 cols * Variables: * high_25in: using high
 resolution profile to sense mixture at 2.5 inch height of the sample. *
 high_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * high_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * high_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: med\_glass.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 glass background using medium resolution profile of millimeter wave
 sensor. * Format(s): .mat * Size(s): 1,527 KB * Dimensions: * Data: 120
 rows x 1024 cols * label: 120 rows x 1 cols * Variables: * med_25in: using
 high resolution profile to sense mixture at 2.5 inch height of the sample.
 * med_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * med_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * med_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: med\_metal.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 metal background using medium resolution profile of millimeter wave
 sensor. * Format(s): .mat * Size(s): 1,531 KB * Dimensions: * Data: 120
 rows x 1024 cols * label: 120 rows x 1 cols * Variables: * med_25in: using
 high resolution profile to sense mixture at 2.5 inch height of the sample.
 * med_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * med_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * med_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: med\_sponge.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 sponge background using medium resolution profile of millimeter wave
 sensor. * Format(s): .mat * Size(s): 3,715 KB * Dimensions: * Data: 120
 rows x 1024 cols * label: 120 rows x 1 cols * Variables: * med_25in: using
 high resolution profile to sense mixture at 2.5 inch height of the sample.
 * med_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * med_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * med_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: med\_wood.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 wood background using medium resolution profile of millimeter wave sensor.
 * Format(s): .mat * Size(s): 1,528 KB * Dimensions: * Data: 120 rows x
 1024 cols * label: 120 rows x 1 cols * Variables: * med_25in: using high
 resolution profile to sense mixture at 2.5 inch height of the sample. *
 med_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * med_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * med_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: low\_glass.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 glass background using low resolution profile of millimeter wave sensor. *
 Format(s): .mat * Size(s): 797 KB * Dimensions: * Data: 120 rows x 1024
 cols * label: 120 rows x 1 cols * Variables: * low_25in: using high
 resolution profile to sense mixture at 2.5 inch height of the sample. *
 low_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * low_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * low_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: med\_metal.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 metal background using low resolution profile of millimeter wave sensor. *
 Format(s): .mat * Size(s): 797 KB * Dimensions: * Data: 120 rows x 1024
 cols * label: 120 rows x 1 cols * Variables: * low_25in: using high
 resolution profile to sense mixture at 2.5 inch height of the sample. *
 low_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * low_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * low_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: med\_sponge.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 sponge background using low resolution profile of millimeter wave sensor.
 * Format(s): .mat * Size(s): 797 KB * Dimensions: * Data: 120 rows x 1024
 cols * label: 120 rows x 1 cols * Variables: * low_25in: using high
 resolution profile to sense mixture at 2.5 inch height of the sample. *
 low_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * low_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * low_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels. ## Details for: low\_wood.mat * Description:
 This is for classifying different amount of soil and biochar mixture under
 wood background using low resolution profile of millimeter wave sensor. *
 Format(s): .mat * Size(s): 797 KB * Dimensions: * Data: 120 rows x 1024
 cols * label: 120 rows x 1 cols * Variables: * low_25in: using high
 resolution profile to sense mixture at 2.5 inch height of the sample. *
 low_50in: using high resolution profile to sense mixture at 5.0 inch
 height of the sample. * low_75in: using high resolution profile to sense
 mixture at 7.5 inch height of the sample. * low_100in: using high
 resolution profile to sense mixture at 10.0 inch height of the sample. *
 labelCategorical: Total 6 classes, each label has 20 samples, therefore
 totally it has 120 labels.