Timeline for How did single dish (or single receiver) radio telescopes originally generate images?
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 15, 2016 at 8:27 | comment | added | uhoh | Actually I'll leave those to another day (and another question). Thanks! | |
| Jun 15, 2016 at 8:27 | vote | accept | uhoh | ||
| Jun 15, 2016 at 8:05 | comment | added | uhoh | Analog TV looked better than it actually was because it redrew many images per second and our eye averaged. The old analog scanning electron microscopes that might take minutes to scan one image to a piece of polaroid film for ultimate resolution were plagued by all sorts of drifts, sample charging, mechanical, emission current/emitter condition... oh it was such a pain before Zeiss made the first digital SEM and changed the world! (note: I have no affiliation with Zeiss - the old analogue SEMs were a royal pain!) | |
| Jun 15, 2016 at 8:03 | comment | added | uhoh | Sounds good! If the signal were weak you could build it up over many cycles, or move the telescope at a rate slightly faster/slower than the sky. But if there is drift in the gain of the telescope (this is the 'old days') or changes in the atmosphere (like water content) or even maybe the ionosphere, won't that cause parts of the image to be out of calibration with other parts? | |
| Jun 15, 2016 at 7:19 | history | answered | James Screech | CC BY-SA 3.0 |