Ursa Space's SAR Point Exploitation (SPEX) tool is a valuable resource to discover hotspots for change.
Table of Contents
1. Accuracy Metrics
2. Product Generation Latency Metrics
1. SPEX GeoJSON File Format
2. Example Product
| Status | Operational |
| Launch year | Late 2021 |
| Latest release | Version 2, late 2022 |
| Data source | SAR |
| Delivery formats | JSON |
| Delivery methods | API, S3 |
What is the Product?
Ursa’s SAR Point Exploitation (SPEX) product is an operational, SAR-based solution for highlighting bright objects that stand out from their neighborhood. The targets highlighted by this detection process tend to be human-made objects that are of interest in many applications and use cases. The detected objects are not classified or categorized, but may act as a cue for human analysis or further downstream processing. The sensitivity and size of objects of interest are tunable parameters and may be set according to a particular application if desired.
This product can be generated from stripmap, spotlight, or scan SAR imagery.
Currently, imagery from the following SAR data providers are compatible with Ursa’s SPEX processor:
-
Sentinel
-
e-GEOS
-
Airbus
-
SIIS
-
Capella
-
ICEYE
-
MDA
Performance Metrics
Accuracy Metrics
Because SPEX acts as a very generic object detector, and objects of interest (and conversely the objects which was considered nuisances or false alarms) can vary drastically from application to application, the accuracy performance cannot be analyzed in a general sense. To understand the accuracy performance of SPEX for a specific application, please contact your Ursa Solutioner or Sales Engineer.
Product Generation Latency Metrics
The following metrics represent approximate processing latency estimates.
-
Time from image capture to Ursa acquisition: 4-12 hours (varies)
-
Time from Ursa acquisition to product delivery: 10-15 minutes
-
Time from automated results to quality controlled results: 24-48 business hours (varies)
Standard Output File Formats
A standard SPEX Detection product will include the following files:
| File Name | File Type | Description |
| spex_detections.json | SPEX Detections GeoJSON File | GeoJSON file containing one feature for every detected SPEX, as well as supplemental information about the SAR collection and the algorithms used. Georeferencing is provided using a WGS 84 projection. |
If another form of this data is required, Ursa can also provide the product in alternative formats. Please contact your Ursa Solutioner or Sales Engineer for more information.
SPEX GeoJSON File
The metadata and property fields provided within the SPEX Detections GeoJSON file are found in the following documents.
Ursa Analytic: GeoJSON Product Information
Object Detection: Product Format
The SPEX Detection product uses the following feature properties to annotate object detections. These properties are described in the Object Detection Product Format page.
-
uuid
-
detectionNumber
-
geometrySource
-
sarLatitude
-
sarLongitude
-
sarLength
-
sarWidth
-
sarHeading
-
sarDetectionTimeUTC
Example Product Output
{
"type": "FeatureCollection",
"product": {
"productType": "Object Detection",
"documentVersion": "0.1"
},
"processors": [
{
"processorName": "SPEX Application",
"version": "2.0.2",
"parameters": {
"aoi": null,
"ground_projection": "GTC",
"reference_height": null,
"polarization": null,
"remap": "remap_standard",
"min_object_size_pixels": 5,
"max_object_size_square_meters": null,
"threshold": 0.75,
"multilook_factor": 1,
"quantize_levels": null,
"blur_width_meters": 0
}
}
],
"sensorData": [
{
"sensorDataIndex": 0,
"sensorName": "CSKS1",
"sensorType": "SAR",
"sensorMode": "DYNAMIC STRIPMAP: ES-31",
"productType": "SLC",
"vendorId": "23SEP22_CSKS1_154134Z",
"startTimeUTC": "2022-09-23T15:41:34.775872Z",
"geometryReference": "POINT Z (29.416473388671875 51.49331283569336 0)",
"azimuthAngle": 96.09805607974188,
"incidenceAngle": 56.61229102647734,
"polarization": "HH",
"footprint": "POLYGON ((29.496922355528778 51.533574500025885, 29.48106997364771 51.443112966846975, 29.33629442129441 51.45280183029825, 29.351856251306483 51.54325479773766, 29.496922355528778 51.533574500025885))"
}
],
"features": [
{
"type": "Feature",
"geometry": {
"type": "Polygon",
"coordinates": [
[
[
29.4065455640152,
51.5308672753559
],
[
29.4065629667671,
51.5308672753559
],
[
29.4065629667671,
51.5308636635564
],
[
29.4065687676843,
51.5308636635564
],
[
29.4065687676843,
51.5308528281576
],
[
29.4065629667671,
51.5308528281576
],
[
29.4065629667671,
51.530849216358
],
[
29.4065513649325,
51.530849216358
],
[
29.4065513649325,
51.5308528281576
],
[
29.4065455640152,
51.5308528281576
],
[
29.4065455640152,
51.5308564399572
],
[
29.4065397630979,
51.5308564399572
],
[
29.4065397630979,
51.5308636635564
],
[
29.4065455640152,
51.5308636635564
],
[
29.4065455640152,
51.5308672753559
]
]
]
},
"properties": {
"uuid": "3e361f55-5b44-4db3-8994-b9672df047d6",
"detectionNumber": 0,
"geometrySource": "SAR",
"sarLatitude": 51.4985591577856,
"sarLongitude": 29.35467284576592,
"sarLength": 2.008068947121501,
"sarWidth": 2.006351375952363,
"sarHeading": 0.0,
"sarDetectionTimeUTC": "2022-09-23T15:41:34.775872"
}
},
{
"type": "Feature",
"geometry": {
"type": "Polygon",
"coordinates": [
[
[
29.3552132470072,
51.5213104536545
],
[
29.3552364506764,
51.5213104536545
],
[
29.3552364506764,
51.5213068418549
],
[
29.3552422515936,
51.5213068418549
],
[
29.3552422515936,
51.5212960064562
],
[
29.3552364506764,
51.5212960064562
],
[
29.3552364506764,
51.5212923946566
],
[
29.3552132470072,
51.5212923946566
],
[
29.3552132470072,
51.5212960064562
],
[
29.35520744609,
51.5212960064562
],
[
29.35520744609,
51.5213068418549
],
[
29.3552132470072,
51.5213068418549
],
[
29.3552132470072,
51.5213104536545
]
]
]
},
"properties": {
"uuid": "f7384753-d296-4eda-8043-1c08ca6d0720",
"detectionNumber": 1,
"geometrySource": "SAR",
"sarLatitude": 51.53051873669601,
"sarLongitude": 29.370022988822285,
"sarLength": 2.408127064583823,
"sarWidth": 2.008068947121501,
"sarHeading": 90.0,
"sarDetectionTimeUTC": "2022-09-23T15:41:34.775872"
}
}
]
}