Long-term dataset gathered at the JKI deployment 2016 ===================================================== Site information: ----------------- The WSN was deployed at experimental fields of the Julius Kúhn-Institute (JKI) in Braunschweig, Germany (52.29°N, 10.44°E; 75 m elevation) in 2016. In a special experiment the maximum impact of water shortage and drought stress on wheat phenology, physiology, and yield was investigated by the JKI. For details on the experiment, please refer to: Schittenhelm, Kottmann, Kraft, Matschiner, Langkamp-Wedde. "Agronomic performance of winter wheat grown under highly divergent soil moisture conditions in rainfed and water-managed environments". Journal of Agronomy and Crop Science (2018), DOI: 10.1111/jac.12322. Details on the sensor node developed for the deployments, can be found in: Bauer, Siegmann, Jarmer, Aschenbruck. "On the potential of wireless sensor networks for the in-situ assessment of crop leaf area index". Computers and Electronics in Agriculture. 128 (2016), DOI: 10.1016/j.compag.2016.08.019 Topology: --------- GW: IoT-gateway with Raspberry Pi 60 and reference sensor 0x9 as base station Cluster 1: in-situ cluster in drought stress environment with Raspberry Pi 61 and sensors 0x1,0x2,0x5,0x6 Cluster 2: in-situ cluster in well-watered environment with Raspberry Pi 64 and sensors 0x3,0x4,0x7,0x8 Cluster 3: above stand cluster with Raspberry Pi 63 and reference sensors 0x10,0x11 Details on the deployment and its topology can be found in: Bauer, Jarmer, Schittenhelm, Siegmann, Aschenbruck. "Processing and Filtering of Leaf Area Index Time Series Assessed by In-Situ Wireless Sensor Networks". Computers and Electronics in Agriculture. 165 (2019), DOI: 10.1016/j.compag.2019.104867 Note: In the publication "Processing and filtering of leaf area index time series assessed by in-situ wireless sensor networks", node IDs 0xn have been changed as follows: GW: 0x9-->A_1 Cluster 1: 0x1->B_1, 0x2->B_2, 0x5->B_5, 0x6->B_6 Cluster 2: 0x3->B_3, 0x4->B_4, 0x7->B_7, 0x8->B_8 Cluster 3: 0x10->A_2, 0x11->A_3 In the manuscript "Towards a low-cost RSSI-based Crop Monitoring", node IDs 0xn have been changed as follows: GW: 0x9-->GW Cluster 1: 0x1->A, 0x2->B, 0x5->C, 0x6->D Cluster 2: 0x3->G, 0x4->H, 0x7->E, 0x8->F Cluster 3: 0x10->AS Link distances: ------------------- GW<->AS 92m Type: above-above Link Quality: medium (LOS) A<->B 0.3m Type: ground-ground Link Quality: high A<->D 1.2m Type: ground-ground Link Quality: high B<->D 1.2m Type: ground-ground Link Quality: high B<->GW 22.5m Type: ground-above Link Quality: medium A<->GW 23m Type: ground-above Link Quality: medium D<->GW 23m Type: ground-above Link Quality: medium G<->E 3.7m Type: ground-ground Link Quality: low H<->E 3.9m Type: ground-ground Link Quality: low G<->GW 65m Type: ground-above Link Quality: low H<->GW 65m Type: ground-above Link Quality: low Timeline: --------- 2016-04-13: Start of deployment (GW and cluster 1 and 3) 2016-05-03: Start of cluster 2 2016-06-28: End of deployment Data Format: ============ sensor_N.dat: ------------- These files are generated by all TelosB sensors. Using their serial UART interface, sensor data is periodically (every 2 min) logged on the corresponding Raspberry Pi. Example output: 2016-04-15_13:57:47 1460721467 0x9 335;4c9,4ca,4c7,4cc,4cf,4c8,4c9,4ca,4cb,4cb,4ca,4c6,4c8,4ca,4ca,4c8,4c7,4c9,4c7,4c9,4c9,4c9,4ca,4ca,4c9-1828,8b0-2:d4/68;1:d9/68;0:0/0;0:0/0;1:d3/5e;1:d9/6b;0:0/0;0:0/0;0:0/0;2:d4/ Interpretation: Timestamp from PI 2016-04-15_13:59:47 Local unix time 1460721587 Source Address (SA) 0x9 Sequence Number (SN) 336; Light readings (25 values, DN in hex format) 4f3,4f4,4f3,4ef,4f7,4f1,4f3,4f3,4ed,4f3,4f9,4f2,4f3,4f3,4f5,4f2,4f4,4f6,4f2,4f2,4f4,4f3,4f4,4f3,4ee- Temperature readings (DN in hex format) 183d Luftfeuchte readings (DN in hex format) 8be Link Quality array 2:d3/61;2:d9/68;0:0/0;0:0/0;2:d3/5e;2:d9/6b;0:0/0;0:0/0;0:0/0;2:d6/69 This array captures signal strength of captured packets. Every tripel A:B/C contains: 1) A: the difference of own SN and received SN (i.e., a value of 2 means that the sender SN was 334 in this example) 2) B: RSSI, and 3) C LQI. The source address can be derived from the position of the corresponding triple within the array. The triple "0:0/0" at the third position in this case means that sensor 0x9 has not received any packets from sensor 0x3 so far. sensor_base_N.dat: ------------------ All reference sensors additionally produce sensor_N.dat files. Those sensors continuously gather light readings above the canopy and listen to radio transmissions from ground sensors. In case suchlike transmissions are overheard, they extract the light values from the payload and compute the leaf area index (LAI) using their own synchronous light readings. Example output: 2016-04-15_17:32:43 1460734363 0x9, 2 442 1150.59 1244.40 0.55 Interpretation: Timestamp von PI 2016-04-15_17:32:43 Local Time 1460734363 own ID (from reference sensor) 0x9, Source Address (ID of ground sensor) 2 SN (from ground sensor) 442 mean value of light reading bundle (25 values, see above) from ground sensor 1150.59 mean value of light reading bundle (25 values, see above) from reference sensor 1244.40 LAI 0.55 Note: The log files contains some corrupted UART outputs that can easily be identified and removed or repaired, respectively.