20220611-uwb-twr

Experiment details

Authors : Quentin Vey, Réjane Dalcé, Adrien van den Bossche, Thierry Val.

This document presents the dataset 20220611-uwb-twr.json used in the experiments presented in the proposal for demonstration submitted to LCN 2022: Quentin Vey, Réjane Dalcé, Adrien van den Bossche, Thierry Val. Indoor UWB localisation: LocURa4IoT testbed and dataset presentation.

The experiment has taken place on June, 11th 2022 on the LocURa4IoT testbed. Dataset is under ODbL licence. Please cite the following paper on any publication made with this dataset : Quentin Vey, Réjane Dalcé, Adrien van Den Bossche., Thierry Val. Indoor UWB localisation: LocURa4IoT testbed and dataset presentation. 47th IEEE Conference on Local Computer Networks (LCN 2022), IEEE, Sep 2022, Edmonton, Canada. hal-03702352

Scenario description

Please refer to the paper for the full experiment description.

Dataset description

Each line of the dataset is the output of a ranging as a JSON dictionary. These JSON dictionaries are detailed in the following table:

key description example
initiator TWR client (mobile) address “183”
target TWR server (anchor) address “182”
protocol Ranging protocol used for the experiment “TWR”
t1 First message transmission timestamp using client clock 827869768332
t2 First message reception timestamp using server clock 350550466754
t3 Second message transmission timestamp using server clock 350610701964
t4 Second message reception timestamp using client clock 827930006159
skew Client-server clock skew (=skewAck) -5.968155
nlosIndicator Non Line of Sight Indicator (dbm) * 5.014733
tof Time of Flight, expressed as 64GHz ticks (15,65ps) 1356
tofSkew Time of Flight, expressed as 64GHz ticks (15,65ps), after clock skew correction on second message (ACK) 1536.961803
range Final distance estimation (=rangeSkew) 7.169614
rangeSkew Ranging after clock skew correction on second message 7.208881
rangeNoSkew Raw ranging (no skew correction) 6.360108
ranging unit Distance unit for ranging values “m”
seqnum Ranging Sequence Number 1924
rssiRequest Received signal strength indicator of first message (dbm) * -77.901009
rssiAck Received signal strength indicator of second message (dbm) * -77.939378
rssiData Received signal strength indicator of third message (dbm) * -78.213673
temperature Client-side Temperature (°C) 34.400002
distantTemperature Server-side Temperature (°C) 40.099998
registerDump_CIR Data from Channel Impulse response (all fields from this table refer to the second message)
registerDump_CIR.ACC_mem Raw data from Channel Impulse Response accumulator registry ACC_mem as a base64-encoded string (excluding some data at the beginning, see ACC_MEM_first_index) *
registerDump_CIR.ACC_MEM_first_index Index of the first sample of registerDump_CIR.ACC_mem in register ACC_mem 675
registerDump_CIR.RXPACC Preamble Accumulation Count 118
registerDump_CIR.RXPACC_NOSAT Unsaturated Preamble Accumulation Count 118
registerDump_CIR.SFD_LENGTH length of the SFD sequence 16
registerDump_CIR.RXM110K Receiver Mode 110 kbps data rate (1: true / 0: false) 0
registerDump_CIR.DWSFD Use of non-standard SFD sequence (1: true / 0: false) 0
registerDump_CIR.RNSSFD Use of non-standard SFD sequence (1: true / 0: false) 0
registerDump_CIR.FP_INDEX First path index. 16-bit value reporting the position within the CIR data determined by the hardware to be the first path. The 10 most significant bits the integer portion of the position and the 6 least significant bits represent the fractional part. 47914
timestamp unix timestamp -0.157, 6.896, 2.65
localisation.initiator Client position x, y, z (m) -0.157, 6.896, 2.65
localisation.target Server position x, y, z (m) 4.358, 1.331, 2.623
distance Client-server true distance (m) 7.166
rangingError Ranging error (=range-distance, m) 0.003

*: see DecaWave « DW1000 User Manual ».

Example use

Refer to the file draw.py as an example to use the dataset. This script will generate plots of some key metrics, including the figures used in the proposal for demonstration.

usage :

python3 draw.py 20220611-uwb-twr.json

Python module dependencies: matplotlib, numpy