Crossed-slits — where it appears
Named by 2 essays across one field — each of them below, with the objects they name alongside it.
A body that bounces leaves a second swelling in the rows, and one pass reads both
A vehicle's body pitches and bounces on its springs at two frequencies, and a scroll camera's rows answer both: the pitch by turning the camera, the bounce by lifting it through the height climbed between the slits' two moments. One oscillator fitted to a body pitching at 1.4 Hz and bouncing at 1.0 lands between the two, at 1.22 Hz, with the camera over the body's centre, and on the pitch, at 1.41, with it 1.5 metres ahead — too lightly damped either way. Two modes fitted to the same single 800-metre pass read both, the pitch to ±0.02 Hz and the bounce to ±0.03, say plainly whether a bounce is there at all, and expose a bias the earlier readings carried even on a body that does not bounce: a camera ahead of the centre reads a 1.4 Hz pitch as 1.5 unless the fit knows its lever arm.
The rows read where the camera rides on the body, and a camera behind the centre hides the pitch
A scroll camera's rows over a rough road say how far ahead of the body's centre the camera stands, as well as how the body pitches and bounces. One 800-metre pass reads a camera 1.5 metres ahead to ±0.15 metres, costs the pitch's frequency nothing to do it, and removes the bias a fit that puts the camera at the centre carries — a 1.4 hertz pitch read as 1.54 from 2.5 metres ahead, and as 1.80 from a metre behind a body that does not bounce. Behind the centre the camera's rise works against its turn, and a metre back on a body that does not bounce it very nearly cancels the pitch where it rings.
Named alongside it
The objects these essays reach for when they reach for this one.
degrees of freedomIdentifiabilityleast squaresModel errorPushbroom