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technical:description [2025/02/26 15:29] – etienne | technical:description [2025/03/24 17:36] (current) – [(14) Spectral cameras] etienne |
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==== (2) Full-Sun guider ==== | ==== (2) Full-Sun guider ==== |
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A full-sun guider has been setup on the telescope outer ring of the heat protection, near the 1m entrance plate. It uses a 45/500 mm objective, an Herschel prism, a neutral filter, a green continuum 540nm photosphere filter, and a ZWO ASI 178 mono (2kx3k) CMOS camera.The full-sun guider image is always available in the control room of THEMIS. The full-Sun guider images are not meant for pure scientific analysis. Please note that given the location of the entrance pupil and depending on the telescope/dome relative positions, this guider may be momentarily obscured by the dome edge(for less than 30 seconds in any circumstance). <html><font color="#ff9900"> Camera settings can be changed by the user in the control room. Acquisition is left to the needs of the users. </font></html>\\ | A full-sun guider has been setup on the telescope outer ring of the heat protection, near the 1m entrance plate. It uses a 45/500 mm objective, an Herschel prism, a neutral filter, a broadband (10 nm) green continuum 540nm photosphere filter (Baader Planetarium GmbH), and a ZWO ASI 178 mono (2000x3000 pixel²) CMOS camera. The full-sun guider image is always available in the control room of THEMIS. The full-Sun guider images are not meant for pure scientific analysis. Please note that given the location of the entrance pupil and depending on the telescope/dome relative positions, this guider may be momentarily obscured by the dome edge(for less than 30 seconds in any circumstance). <html><font color="#ff9900"> Camera settings can be changed by the user in the control room. Acquisition is left to the needs and appreciation of the user. </font></html>\\ |
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<html><font color="#0000ff"> The image from this camera is an available data product </font></html> [[observation:data#Full-sun guider images| (cf. THEMIS data products)]]. | <html><font color="#0000ff"> The image from this camera is an available data product </font></html> [[observation:data#Full-sun guider images| (cf. THEMIS data products)]]. |
==== (8-9) Broadband Imaging (BBI) filter & camera ==== | ==== (8-9) Broadband Imaging (BBI) filter & camera ==== |
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If illuminated, the BBI camera offers a broadband high-resolution image with a square field-of-view of about ~55"x55". A broadband red filter, with a ~3nm passband centered around 656 nm is placed upstream of the camera. THEMIS BBI camera thus currently provides images or the red visible continuum. | If illuminated, the BBI camera offers a broadband high-resolution image with a square field-of-view of about ~55"x55". A broadband red filter, with a ~3nm passband centred around 656 nm is placed upstream of the camera. THEMIS BBI camera thus currently provides images or the red visible continuum. |
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THEMIS BBI camera is currently a 2000 x 2000 pixels Andor Zyla camera. This camera relies on the scientific CMOS technology (active-pixel sensor). This offers a high quality image of a subset of the THEMIS field-of-view with a very fast read-out, enabling the capture of a burst of images capture (up to 40 images/second) that are ideal for post image reconstruction. | THEMIS BBI camera is currently a 2000 x 2000 pixels Andor Zyla camera. This camera relies on the scientific CMOS technology (active-pixel sensor). This offers a high quality image of a subset of the THEMIS field-of-view with a very fast read-out, enabling the capture of a burst of images capture (up to 40 images/second) that are ideal for post image reconstruction. <html><font color="#ff9900"> Camera acquisition settings can be changed by the user in the THEMIS control room. Acquisition is left to the needs and appreciation of the user. </font></html>\\ |
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<html><font color="#0000ff"> The red continuum images from the BBI camera are an available data product. Post-observation image processing methods & routines (Knox-Thompson reconstruction method) are available </font></html> [[observation:data#Broadband images (BBI) | (cf. THEMIS data products)]]. | <html><font color="#0000ff"> The red continuum images from the BBI camera are an available data product. Post-observation image processing methods & routines (Knox-Thompson reconstruction method) are available </font></html> [[observation:data#Broadband images (BBI) | (cf. THEMIS data products)]]. |
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The THEMIS spectrograph is an essential block of the THEMIS instrumentation that enable the formation of the solar spectrum and its detailed analysis. | The THEMIS spectrograph is an essential block of the THEMIS instrumentation that enable the formation of the solar spectrum and its detailed analysis. |
MTR2 is the advanced version of the original MulTi-Ray spectrograph of THEMIS. MTR2 enables the production of high-spectral resolution spectrograms simultaneously in different wavelengths. This enables the study of different physical properties of the distinct layers of the solar atmosphere. | MTR2 is the advanced version of the original MulTi-Ray spectrograph of THEMIS. MTR2 enables the production of high-spectral resolution spectrographs simultaneously in different wavelengths. This enables the study of different physical properties of the distinct layers of the solar atmosphere. |
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<html><font color="#ff9900"> Numerous user options are available here concerning the choice of the combination of spectral lines. </font></html> | <html><font color="#ff9900"> Numerous user options are available here concerning the choice of the combination of spectral lines. </font></html> |
==== (14) Spectral cameras ==== | ==== (14) Spectral cameras ==== |
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At the exit of the spectrograph, several cameras are placed so that to record simultaneous spectrograms (lambda,y) in different wavebands. The spectrograms have a typical spectral range of 6-7 Å (0.6-0.7 nm) depending of the wavelength. The spatial direction has an extend of 1' when performing polarised observations, 2' otherwise. When performing polarimetric observations, two spectrograms are fitted on the camera field-of-view, each including the opposite polarimetric state (e.g. I+V and I-V Stokes). | At the exit of the spectrograph, several cameras are placed so that to record spectral images (lambda,y) simultaneously in different wavebands. The spectrographic images have a typical spectral range of 6-7 Å (0.6-0.7 nm) depending of the wavelength. The spatial direction has an extend of 1' when performing polarised observations, 2' otherwise. When performing polarimetric observations, two spectrographs are fitted on the camera field-of-view, each including the opposite polarimetric state (e.g. I+V and I-V Stokes). |
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<html><font color="#0000ff"> The spectrographic images from the spectral cameras are the main data product of THEMIS MTR2 spectrograph observation mode. </font></html> [[observation:data#context camera| (cf. THEMIS data products)]] | <html><font color="#0000ff"> The spectrographic images from the spectral cameras are the main data product of THEMIS MTR2 spectrograph observation mode. </font></html> [[observation:data#context camera| (cf. THEMIS data products)]] |