Positional accuracy indicates the reliability of the horizontal and vertical positions of geospatial features relative to their datums. Accuracy standards allow us to quickly and consistently establish positional reliability across different imagery.
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Absolute accuracy
It measures how closely a specific feature in an image aligns with its actual ground position on Earth.
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Relative accuracy
It measures how closely the positions of features align relative to each other within a given image.
CE indicates the possible horizontal distance by which a specific feature might deviate from its actual ground position. The number after CE specifies the confidence value.
For example, an accuracy of 5 m CE90 means you can be 90% confident a specific feature in an image is within a 5 m radius circle around where the image suggests.
LE indicates the possible vertical distance a specific feature might deviate from its actual ground position. The number after LE specifies the confidence value.
For example, an accuracy of 2 m LE95 means you can be 95% confident a specific feature is within 2 m vertically of where the image suggests.
RMSE indicates the average distance a specific feature might deviate from its actual ground position in a given direction. The letters after RMSE specify whether it’s measured in the horizontal x and y or the vertical z directions.
For example, an accuracy of 10 m RMSEx/y/z means a specific feature may vary up to 10 m on average from its actual ground position, measured in the x, y, and z directions.
SE indicates the possible distance a specific feature might deviate from its actual ground position in all directions. The number after SE specifies the confidence value.
For example, an accuracy of 3 m SE90 means you can be 90% confident a specific feature is within a 3 m radius sphere around where the image suggests.
| Collection | Positional accuracy |
|---|---|
| AxelGlobe | < 10 m RMSEx/y/z absolute |
| Beijing-3A | < 10 m CE90 absolute |
| Beijing-3N | < 10 m CE90 absolute |
| BlackSky | Tasking:
Catalog: < 20 m CE90 absolute |
| Constellr | Unknown, can be requested |
| EROS-B | Unknown, can be requested |
| EROS-C | Unknown, can be requested |
| GEOSAT 1 | 22 m CE90 absolute |
| GEOSAT 2 | < 20 m CE90 absolute |
| GHGSat | 15.3 m CE90 absolute |
| GÖKTÜRK-1 | < 10 m CE90 absolute |
| KOMPSAT-3 | 51 m CE90 absolute |
| KOMPSAT-3A | 13.5 m CE90 absolute |
| Landsat 8 | 12 m CE90 absolute |
| Planet | < 10 m CE90 absolute |
| Pléiades | 6.50 m CE90 absolute at nadir |
| Pléiades Neo | Tasking: 5 m CE90 absolute at nadir Catalog: 5 m CE90 absolute at nadir (HD15: < 3.5 m CE90 absolute at nadir) |
| Satellogic | 10 m CE90 absolute |
| SatVu | Basic Primary: ≤ 200 m CE90 SBT: ≤ 15 m CE90 |
| Sentinel-2 | 8 m CE95 absolute |
| SPOT | 10 m CE90 absolute |
| TripleSat | < 20 m CE90 absolute at nadir |
| Vantor | < 5 m CE90 absolute |
| Collection | Positional accuracy |
|---|---|
| Dragonette-1 | Location-dependent, from 25 m to 100 m CE90 absolute |
| Pixxel | 12 m CE90 absolute |
| Collection | Positional accuracy |
|---|---|
| Bluesky Aerial | 1 m RMSE absolute |
| Getmapping Aerial | Unknown, can be requested |
| Hexagon Aerial | 2.6 m CE90 absolute |
| IO Aerospace Aerial | With GCPs: 25 cm absolute |
| Vexcel Aerial | Ortho: 1 m RMSEx/y/z absolute True Ortho: 15 cm RMSEx/y/z absolute Obliques and Nadir:
|
| Collection | Positional accuracy |
|---|---|
| Globhe Optical | With GCPs: < 10 cm absolute |
| Collection | Positional accuracy |
|---|---|
| Capella Space | Unknown, can be requested |
| ICEYE | Spot: 6 m RMSE absolute Site: 6 m RMSE absolute Strip: 6 m RMSE absolute Scan (standard): 15 m RMSE absolute Scan (wide): 27 m RMSE absolute |
| KOMPSAT-5 | 6.22 m CE90 absolute |
| StriX | Unknown, can be requested |
| TerraSAR-X | Horizontal: 10 m CE90 absolute Vertical:
|
| Umbra | 8 m CE90 absolute |
| Collection | Positional accuracy |
|---|---|
| Airbus Elevation | Elevation 0.5: Horizontal:
Vertical:
Elevation 1: Horizontal:
Vertical:
Elevation 4: Horizontal:
Vertical:
|
| Bluesky Elevation | Horizontal: 1 m RMSE absolute Vertical: 1.5 m RMSE absolute |
| Globhe Elevation | With GCPs: < 10 cm absolute |
| Hexagon Elevation DSM | 30 cm RMSEx/y/z relative 60 cm RMSEx/y/z relative |
| NEXTMap | NEXTMap One:
NEXTMap 6:
|
| PlanetDEM | Horizontal: < 7 m CE90 absolute Vertical: < 7 m LE90 absolute |
| Vexcel Elevate | From 5.5 to 7.5 cm: 15 cm RMSEx/y/z absolute From 15 to 20 cm: 1 m RMSEx/y/z absolute |
| Vivid Terrain | Horizontal:
Vertical:
|
| WorldDEM Neo | Horizontal: 6 m CE90 absolute Vertical:
|
| WorldDEM4Ortho | Horizontal: 6 m CE90 absolute Vertical:
|
| Collection | Positional accuracy |
|---|---|
| NV5 Lidar | Horizontal: 30 cm absolute Vertical: 10 cm absolute |
| Collection | Positional accuracy |
|---|---|
| Airbus Basemap | ≤ 5 m CE90 absolute |
| Airbus Ground Control Points | Standard: < 1 m CE90 Premium: < 20 cm CE90 |
| Airbus Space Reference Points | 3 m CE90 |
| ASTERRA | 6 m |
| PlanetSAT | Unknown, can be requested |
| Regrid | Unknown, can be requested |
What does "at nadir" mean? What does "at nadir" mean?
When a sensor points at a target directly below the sensor, it points at nadir. Optical sensors are most accurate when pointing at nadir due to the minimal distance between the sensor and the target.