This document provides information about using the ElasticSearch platform to search through Sentinel-1 imagery and metadata to analyze images related to a central Italy earthquake from August 24th 2016. It describes querying the data to find pre-event and post-event images, extracting orbit state vectors and ground measurement points, and using these to analyze backscatter profiles and detect anomalies.

3. ©ESA/PPO.LABS/NORUT/NGU

5. Central Italy Earthquake August 24th

9. B
First observa<on
Second observa<on
Post-event image : 2016 Aug 24th
Pre-event image : within 6 months before
with min 80% coverage
Baseline < 120m
Burst Sync < 5 ms

11. "_source": {
"platformShortName": "S1A",
...
"modified": "2016-08-29T12:05:55.72414",
"published": "2016-08-29T12:05:55.722029Z",
"startDate": "2016-08-26T07:19:43.426903+02:00",
"endDate": "2016-08-26T07:20:11.341358+02:00",
"geometry": {
"coordinates": [
[
[
12.880328,
40.986172
],
[
9.856127,
41.385281
],
[
10.212059,
43.060333
],
[
13.319739,
42.661736
],
[
12.880328,
40.986172
]
]
],
"type": "Polygon"
},
"identifier": "S1A_IW_SLC__1SDV_20160826T051943_20160826T052011_012767_0141C5_3599",
...
}

13. POST sentinel1/eopfeature/_search
{
"query": { "and": {
"filters": [{
"geo_shape" : {
"geometry" : {
"relation" : "intersects",
"shape" : {
"coordinates": [[
[ 12.880328, 40.986172 ],
[ 9.856127, 41.385281 ],
...
]], "type" : "Polygon" }}},
"range": {
"start": {
"gte": "2016-02-24",
"lte": "2016-08-23"}},
},
"term": {
"track": "128" }
]}
}}

14. ü Post-event image : 2016 Aug 24th
ü Pre-event image : within 6 months
before with min 80% coverage
q Baseline < 120m
q Burst Sync < 5 ms

16. {
"platform": "S1A",
"type": "SLC",
"time": "2017-02-06T08:31:48.027691Z",
"frame": "EarthFixed",
"absoluteOrbit": 15160,
"position": [
-5613366.283966,
4302302.834969,
-256349.609754
],
"velocity": [
756.880948,
1415.929115,
7425.469561
]
}

17. OSV 1 (tn)
OSV 2 (tn+10s)
OSV 3 (tn+20s)
OSV 4 (tn+30s)
OSV 5 (tn+40s)
tn + 24.341s

18. POST sentinel1/eoporbit/_search
{
"aggs": {
"OSV": {
"scripted_metric": {
"init_script": {
"_comment" : "Init array of vectors and the timestamp",
"file": "init_osv.py"
},
"map_script" : {
"_comment" : "Load orbit state vectors",
"file": "load_osv.py"
},
"reduce_script" : {
"_comment" : "Robust Cublic Spline interpolation",
"file": "cubic_spline_interpolation.py"
}
}
}
~ 50
orbit state vectors

19. First observa<on
Second observa<on

20. {
"platform": "S1A",
"azimuthTime": "2017-02-06T08:30:45.951147Z",
"slantRangeTime": 0.005821934184880311,
"line": 15174,
"pixel": 12660,
"latitude": -4.903591527542559,
"longitude": 147.6990386159871,
"height": -0.000001518987119197845,
"incidenceAngle": {
"value": 38.98923179289942,
"uom": "deg"
},
"elevationAngle": {
"value": 34.53983660078405,
"uom": "deg"
},
"modified": "2017-02-06T15:11:51.464773Z"
}

21. POST sentinel1/eoppoint/_search
{
"aggs": {
"slantRange": {
"avg": {
"field": "slantRangeTime"
}
}
},
"query": {
"fuzzy": {
"azimuthTime": {
"value" : "2016-08-24T10:05:07.276Z",
"fuzziness" : "700ms"
}
}
}
}

22. B
First observa<on
Second observa<on
S

23. ~ 1,000,000 scenes
~ 13,000,000 orbit state vectors
~ 270,000,000 ground points
# documents

32. {
"platform": "S1A",
"dataset_id": "S1A_IW_GRDH_1SDV_20160729T182822_20160729T182847_012367_013456_E8BF",
"num_lines": 25184,
"num_pixels": 16804,
"stat_fn": "norm",
"stat_fn_paramaters": {
“mean": -13.9180515377,
“stddev": 2.52405823515
},
"dB_spread": {
"pctl5th": -18.6049933434,
"pctl95th": -10.1168370247,
"diff": 8,4881563187
},
"modified": "2017-02-06T15:11:51.464773Z"
}

33. POST sentinel1/backscatter_profile/_search
{
"aggs": {
"anomaly": {
"scripted_metric": {
"init_script": {
"_comment" : "Init functions & anomaly indices",
"file": "init_anomaly_idx.py"
},
"map_script" : {
"_comment" : "Load PDF and CDF from stat fn",
"file": "load_stat.py"
},
"reduce_script" : {
"_comment" : “Compute anomaly indices",
"file": "compute_anomaly_idx.py"
}
},
}

34. i1 0.25463341
i2 0.18215659
i3 0.31308018
i1 0.00552214
i2 0.
i3 0.00552214
i1 0.01139076
i2 0.05227872
i3 0.05350527
i1 0.03202082
i2 0.16190536
i3 0.16504144
i1 0.
i2 0.03447718
i3 0.03447718
i1 0.15261477
i2 0.
i3 0.15261477
i1 0.64931845
i2 0.41153427
i3 0.76874892
i1 1.
i2 1.
i3 1.41421356

36. Elas<csearch
Elas<csearch.net + NEST
OpenSearch Formats
Geo &
Time EOP Correla<on
Geo
JSON
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Pladorm
Catalogue

37. Elas<csearch Nodes Nodes Nodes
HA + Load balancer
5
Intel® Xeon® E3-1275 v5
Quad-Core Skylake
RAM 64GB DDR4 ECC
2 x 512 GB SSD (RAID 1)

38. 0
2
4
6
8
10
12
2014 2015 2016 2017 2018 2019 2020
Millions
Sen<nel-1 Sen<nel-2 Sen<nel-3 Sen<nel-4 Sen<nel-5

41. Questions ?