MAPS performance
Sensor performance criteria quoted industry-wide are often ill defined or plain misleading. MAPS performance is assessed in several ways, each with different utility. These specifications are explained here.
Definitions
Accuracy
Accuracy measures how close the result is to the actual value we were trying to achieve. The accuracy values shown below are based on our simulated tests.
Precision
Precision measures the consistency of our system and gives information about the relative accuracy in application. High precision is enough if achieving a high global accuracy is not needed but to measure the degree of displacement.
Resolution
Resolution shows the theoretical accuracy of our system, i.e. the absolute limit of the technology.
Noise floor
Noise floor measures the degree of change in a stationary state.
Repeatability
Repeatability shows if the results can reliably be repeated in various setups. In case of the MAPS device experiments have been conducted at NPL (National Physical Laboratory), ant they have been meaningfully repeated in our own laboratory as well as simulated tests.
Conditions
accuracy, resolution, repeatability, noise floor.
Results
| 1 megapixel | 4 megapixel | 9 megapixel | |
|---|---|---|---|
| Planar position (x, y) | |||
| Accuracy | 1.12e-06 m | 3.37e-07 m | 4.46e-07 m |
| Precision* | 2.55e-08 (2.51e-08, 2.59e-08) m | 6.80e-08 (6.70e-08, 6.89e-08) m | 9.06e-08 (8.94e-08, 9.19e-08) m |
| Resolution | 8.95e-13 m | 8.95e-13 m | 8.95e-13 m |
| Noise floor | |||
| Repeatability | |||
| Measurement range | 0.021355 m to 0.02136 m | 0.021355 m to 0.02136 m | 0.021355 m to 0.02136 m |
| Depth (z) | |||
| Accuracy | 4.13e-06 m | 1.63e-07 m | 1.62e-07 m |
| Precision* | 7.15e-07 (7.05e-07, 7.25e-07) m | 1.82e-08 (1.79e-08, 1.84e-08) m | 1.85e-08 (1.82e-08, 1.87e-08) m |
| Resolution | 1.22e-13 m | 1.22e-13 m | 1.22e-13 m |
| Noise floor | |||
| Repeatability | |||
| Measurement range | 0.0037 m to 0.007 m | 0.0037 m to 0.007 m | 0.0037 m to 0.007 m |
| Off-angle (x-, y- axis rotation) | |||
| Accuracy | 3.50e-02 rad | 1.40e-04 rad | 1.33e-04 rad |
| Precision* | 1.00e-02 (9.92e-03, 1.02e-02) rad | 1.60e-05 (1.57e-05, 1.62e-05) rad | 1.59e-05 (1.57e-05, 1.61e-05) rad |
| Resolution | 1.59e-13 rad | 1.59e-13 rad | 1.59e-13 rad |
| Noise floor | |||
| Repeatability | |||
| Measurement range | 0 rad to 0.0349065850399 rad | 0 rad to 0.0349065850399 rad | 0 rad to 0.0349065850399 rad |
| Planar rotation (z axis) | |||
| Accuracy | 1.08e-03 rad | 2.67e-05 rad | 2.51e-05 rad |
| Precision* | 2.21e-05 (2.18e-05, 2.24e-05) rad | 2.73e-06 (2.69e-06, 2.77e-06) rad | 2.78e-06 (2.74e-06, 2.81e-06) rad |
| Resolution | 1.07e-14 rad | 1.07e-14 rad | 1.07e-14 rad |
| Noise floor | |||
| Repeatability | |||
| Measurement range | 0 rad to 0.7853981633974 rad | 0 rad to 0.7853981633974 rad | 0 rad to 0.7853981633974 rad |
* confidence interval for the standard deviation of 10000 random tests at a 95% confidence level
