Time-To-Contact Estimates for Observer versus Target Motion
Bibliographic record
Abstract
The ratio (τ) of a moving target's angular size to the rate of change in its angular size can be used by observers to judge the time remaining before they will collide with the target. We consider here whether optical flow information, consistent with simulated observer motion, affects observers' estimates of time-to-contact (TTC). Estimates of TTC were obtained when either the observer approached a stationary target or the target approached a stationary observer. The visual information for τ was the same in both conditions, whereas the visual information for observer self-motion was varied. For the low closing velocities, (3 and 6 eyeheights/sec) there was no significant difference in the estimated TTC for observer motion versus target motion. However, there was a significant difference for the highest closing velocity (12 eyeheights/sec). This result suggests that visual information, specifying self-motion, may be used either in combination with or in place of τ to estimate TTC during simulated locomotion. The present findings have practical implications for both the use of τ in judging TTC and the rendering of terrain texture detail in high-fidelity flight simulators.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.021 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".