RE: RE[2]: ATM Solar spectrograph web page

["Antonio de Ugarte Postigo" <ugarte@mad.servicom.es>]

Dwight,
    First let me excuse for the delay in the reply, I've been out some days.
The project that you talk about is really interesting. I've been thinking of
a project of this kind for some time, and this sounds really attractive. I
had thought about attaching a scan-cam at the end of an instrument like the
one on the ATM page to get a complete image of the Sun, and the one you talk
about sounds like a nice alternative.
    I would really appreciate if you could give me more data about it. I am
very interested in how the motors were used to tilt the mirrors and how good
was the quality of the image. It would be really good if you could send me a
rough drawing of it. Anyway, thanks a lot for the message.
    By the way I have been making adjustments to my web page, and I think
that it works correctly now. Please have a look at it:
http://www.ucm.es/info/Astrof/JAZ/FOCUSS/principi.htm
    Clear skies,

Antonio de Ugarte Postigo

-----Mensaje original-----
De: Dwight Elvey <elvey@hal.com>
Para: ugarte@mad.servicom.es <ugarte@mad.servicom.es>
Fecha: miércoles 31 de marzo de 1999 2:31
Asunto: RE[2]: ATM Solar spectrograph web page


>Hi Antonio
> No, it was different. The one on the ATM page is fixed
>and doesn't show the entire disk of the sun. The one
>I saw used only one grating and a longer light path
>to get the spectral separation. There was a slit
>at the start to pick part of the solar image, and
>an analyzing slit at the end that filtered only
>the narrow band. In front of the first slit was
>a mirror that wobbled or oscillated from a small
>motor. Behind the analyzing slit was another mirror
>that also was connected to the first wobbling mirror.
>The second mirror would re-introduce the scanning
>of the image. The system was folded by a single mirror
>at the end of a long box. The box was fixed but he had
>a small heliostat made from a mirror and one of those
>small Byers camera drive mounts ( modified drive speed
>to 1/2 ). As I recall, the light path was:
>1. Heliostat mirror
>2. Input objective ( small achromat lens about 60mm )
>3. Input wobble mirror.
>4. First slit ( at focus of objective )
>5. Across length of about 8 foot box.
>6. Large mirror spherical ( would be better as elliptical
>     but he said it was so long a focal length, it didn't
>     make much difference. About 8 inches diameter. )
>7. Back along the length of box.
>8. Bounce off diffraction grating ( angle adjustable )
>9. Bounce off small flat mirror next to grating.
>10. Back across the length of box.
>11. Reflected by large mirror again.
>12. Through analyzing slit.
>13. Over second wobble mirror.
>14. Another objective type lens
>15. To eyepiece.
>
>I'm not sure about steps 9 and 14 but I'm sure
>they would need to be there.
> Does all this make sense. I wish I'd written the
>fellows name down and taken some notes.
>Dwight
>
>