espargos-0005 Dataset: Four phase- and time-synchronous ESPARGOS antenna arrays in a lab roob
Four ESPARGOS arrays are placed in the corners of a lab room. Even though they are distributed in space, they are synchronized in both time and phase thanks to wired clock / phase distribution.
36.562 MHz
Signal Bandwidth
117
OFDM Subcarriers
2023114
Data Points
20380.3 s
Total Duration
61.3 GB
Total Download Size
32
Number of Antennas
Indoor
Type of Environment
2.462000 GHz
Carrier Frequency
Global
Synchronization
3D Tachymeter
Position-Tagged
802.11n
WiFi Standard
Experiment Setup
Data Analysis
Antenna Configuration
ESPARGOS 1: espargosnorth
ESPARGOS 2: espargoswest
ESPARGOS 3: espargossouth
ESPARGOS 4: espargoseast
Python: Import with TensorFlow
#!/usr/bin/env python3
import tensorflow as tf
raw_dataset = tf.data.TFRecordDataset(["tfrecords/espargos-0005-meanders-nw-se.tfrecords", "tfrecords/espargos-0005-meanders-ne-sw-1.tfrecords", "tfrecords/espargos-0005-meanders-ne-sw-2.tfrecords", "tfrecords/espargos-0005-radial-1.tfrecords", "tfrecords/espargos-0005-radial-2.tfrecords", "tfrecords/espargos-0005-spiral.tfrecords", "tfrecords/espargos-0005-randomwalk-1.tfrecords", "tfrecords/espargos-0005-randomwalk-2.tfrecords", "tfrecords/espargos-0005-randomwalk-3.tfrecords", "tfrecords/espargos-0005-randomwalk-4.tfrecords", "tfrecords/espargos-0005-heartshape-1.tfrecords", "tfrecords/espargos-0005-heartshape-2.tfrecords"])
feature_description = {
"csi": tf.io.FixedLenFeature([], tf.string, default_value = ''),
"pos": tf.io.FixedLenFeature([], tf.string, default_value = ''),
"rssi": tf.io.FixedLenFeature([], tf.string, default_value = ''),
"time": tf.io.FixedLenFeature([], tf.string, default_value = ''),
}
def record_parse_function(proto):
record = tf.io.parse_single_example(proto, feature_description)
# Channel coefficients for all antennas, over all subcarriers, complex-valued
csi = tf.ensure_shape(tf.io.parse_tensor(record["csi"], out_type = tf.complex64), (4, 2, 4, 117))
# Position of transmitter determined by a tachymeter pointed at a prism mounted on top of the antenna, in meters (X / Y / Z coordinates)
pos = tf.ensure_shape(tf.io.parse_tensor(record["pos"], out_type = tf.float64), (3))
# Received signal strength indicator (in dB) for all antennas
rssi = tf.ensure_shape(tf.io.parse_tensor(record["rssi"], out_type = tf.float32), (4, 2, 4))
# Timestamp of measurement, seconds since UNIX epoch
time = tf.ensure_shape(tf.io.parse_tensor(record["time"], out_type = tf.float64), ())
return csi, pos, rssi, time
dataset = raw_dataset.map(record_parse_function, num_parallel_calls = tf.data.experimental.AUTOTUNE)
# Optional: Cache dataset in RAM for faster training
dataset = dataset.cache()Configuration Variants and Pointcloud
:
Pointcloud Download and Usage Instructions
For this dataset, we provide a pointcloud of the environment, which was generated using a 3D scanning device. You may find the pointcloud useful for visualization purposes or to reconstruct and verify 3D models. Pointclouds can be viewed and edited with applications like CloudCompare.
The tachymeter was used to create a pointcloud scan. While it is stationed in the middle of the measurement area for the pointcloud scan, it was stationed elsewhere while the robot was moving. The coordinate system of the pointlcoud is the same coordinate system that was also used for the rest of the dataset (datapoint positions, antenna array positions).
The pointcloud is available for download as a .pts file.
PTS files are simple text files with the following format:
- The first line contains the number of datapoints in the scan
- The other lines contain
(x, y, z)coordinates, reflection intensity and(r, g, b)color, e.g.:
x y z i r g b
6.9912 -19.5173 14.7111 -546 183 190 174
6.9930 -19.5178 14.7112 -505 162 171 154
6.9888 -19.5181 14.7098 -570 193 200 184
6.9902 -19.5111 14.7109 -578 184 191 173
How to Cite
Please refer to the home page for information on how to cite any of our datasets in your research. This particular dataset is currently not public. Please contact us if you want to cite this dataset in any of your publications.
A Note on WiFi Subcarriers, Bandwidth and Interpolation
WiFi has a concept of "guard" subcarriers, which act as guard bands that protect against interference with systems on neighboring WiFi channels. This means that not all subcarriers get driven (i.e., not all subcarriers contain useful QAM symbols), some subcarriers simply carry zeroes. If these subcarriers are at the edge of the considered spectrum, CSI from these guard subcarriers is simply not included in the dataset. This explains the odd (non-power of two) number of subcarriers and the strange OFDM signal bandwidth. Otherwise, if the guard subcarriers are not at the edges of the spectrum, linear interpolation is used to assign realistic values to these guard subcarriers. This case occurs when using channel bandwidths greater than 40MHz.
A Note on Synchronization
To make sense of the measured CSI data, please take into account:- All ESPARGOS synchronized in phase and time: All receive antennas in all ESPARGOS antenna arrays are synchronized in time and phase. The only unknown quantities are the time of transmission and the phase of transmission.
Download
This dataset consists of 12 files. Descriptions of these files as well as download links are provided below.
espargos-0005-meanders-nw-se
Robots follows a northwest-southeast meander pattern (relative to the north / east / south / west array naming scheme)
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-meanders-ne-sw-1
Robots follows a northeast-southwest meander pattern (relative to the north / east / south / west array naming scheme), only parts of the measurement area
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-meanders-ne-sw-2
Robots follows a northeast-southwest meander pattern (relative to the north / east / south / west array naming scheme), complete measurement area
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-radial-1
Robots follows a pattern of radial trajectories, from middle of measurement area to walls, first part
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-radial-2
Robots follows a pattern of radial trajectories, from middle of measurement area to walls and back, second part
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-spiral
Robots follows an anti-clockwise spiral trajectory, starting in the center and moving towards the perimeter, slow robot speed
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-randomwalk-1
Robot follows a pseudorandom trajectory inside the measurement area, with robot speed a bit higher than otherwise
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-randomwalk-2
Robot follows a short pseudorandom trajectory inside the measurement area, robot speed back to normal (slow)
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-randomwalk-3
Robot follows a pseudorandom trajectory inside the measurement area, robot speed back to normal (slow)
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-randomwalk-4
Robot follows a pseudorandom trajectory inside the measurement area, robot speed back to normal (slow)
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-heartshape-1
Robot follows a heart-shaped trajectory inside the measurement area, robot speed is very slow
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.
espargos-0005-heartshape-2
Robot follows another heart-shaped trajectory inside the measurement area (rotated by 90 degrees), robot speed is very slow
File Size
Data Points
Duration
Standard: There is only one configuration variant called the "Standard" configuration.