{"id":7977,"date":"2024-12-15T00:25:54","date_gmt":"2024-12-14T20:25:54","guid":{"rendered":"https:\/\/cosmo.yerphi.am\/?page_id=7977"},"modified":"2025-01-10T16:07:32","modified_gmt":"2025-01-10T12:07:32","slug":"astron-2-precision-stabilization-system","status":"publish","type":"page","link":"https:\/\/cosmo.yerphi.am\/index.php\/astron-2-precision-stabilization-system\/","title":{"rendered":"ASTRON-2: precision stabilization system"},"content":{"rendered":"<p>&nbsp;<\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 18pt;\"><strong>Lead designer A. Zakharyan<\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<table style=\"border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 8%;\">\u00a0<\/td>\n<td style=\"width: 84%;\">\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">In 1989-1991, right up to the collapse of the USSR, SKB Granit carried out work to create a precision guidance system for the large T-170 orbital telescope under the promising SPECTRUM-UV project, which is a natural continuation of the ASTRON project.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">Currently, this telescope is being created at the NPO <\/span><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">Lavochkin (Russia) and is the basic instrument of the international observatory WSO.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">The main characteristics of the telescope are as follows:<\/span><\/p>\n<ul style=\"text-align: justify;\">\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">Ritchie-Chretien optical system,<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">diameter of the main mirror 1.7 m,<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">secondary mirror diameter 0.5 m,<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">equivalent focal length 17 m,<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">distance between mirrors 3.5 m.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">field of view 40 arcmin.<\/span><\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">The telescope must provide exceptionally high image quality in the focal plane &#8211; close to diffraction in the center, and in the field no worse than 1 arcsec. In this regard, very high demands are placed on the precise guiding system of this telescope.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">At SKB Granit, for this telescope, a version of a two-loop iterative system with an original structure was developed and tested. The image position in the system is measured using a star sensor in the focal plane, either directly or offset.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">The executive element of the first low-frequency tracking circuit with a bandwidth of about 0.5 Hz is a movably mounted secondary mirror of the telescope (similar to the guiding system in the ASTRON telescope). The secondary mirror is tilted around the neutral point of the telescope.<\/span><\/p>\n<figure id=\"attachment_9001\" aria-describedby=\"caption-attachment-9001\" style=\"width: 239px\" class=\"wp-caption alignright\"><a href=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-01.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-9001\" src=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-01.jpg\" alt=\"Image motion compensator\" width=\"239\" height=\"199\" srcset=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-01.jpg 1600w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-01-300x250.jpg 300w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-01-1024x853.jpg 1024w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-01-768x640.jpg 768w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-01-1536x1280.jpg 1536w\" sizes=\"auto, (max-width: 239px) 100vw, 239px\" \/><\/a><figcaption id=\"caption-attachment-9001\" class=\"wp-caption-text\"><span style=\"font-size: 12pt;\">Image motion compensator<\/span><\/figcaption><\/figure>\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">The second, high-speed precision circuit had a bandwidth of up to 15-20 Hz and was built using an optical image motion compensator. This compensator is a flat diagonal mirror controlled by a biaxial piezoelectric drive.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">Main characteristics of the compensator:<\/span><\/p>\n<ul>\n<li><span style=\"color: #000000; font-family: arial, helvetica, sans-serif; font-size: 14pt; text-align: justify;\">mirror diameter 100 mm,<\/span><\/li>\n<li><span style=\"color: #000000; font-family: arial, helvetica, sans-serif; font-size: 14pt; text-align: justify;\">maximum deviation angle for each axis \u00b13.5 arcmin,<\/span><\/li>\n<li><span style=\"color: #000000; font-family: arial, helvetica, sans-serif; font-size: 14pt; text-align: justify;\">operating frequency range 0\u202625 Hz<\/span><\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">When developing this system, maximum use was made of the experience accumulated during the design and long-term operation in orbit of the precision guidance system of the ASTRON space station.<\/span><\/p>\n<p style=\"text-align: justify;\">\u00a0<\/p>\n<hr style=\"height: 2px; border-width: 0; color: gray; background: gray;\" \/>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt; color: #000000;\">The system was tested as part of a ground-based technological sample of the ASTRON telescope at SKB Granit. Below are the results of ground tests illustrating the operation of the developed system.<\/span><\/p>\n<table style=\"border-collapse: collapse; width: 100%; height: auto;\">\n<tbody>\n<tr height: auto;>\n<td style=\"width: 50%; height: auto;\"><a href=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-02b.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-9026 size-full\" style=\"margin-top: 0px; margin-bottom: 0px;\" src=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-02b.jpg\" alt=\"\" width=\"2000\" height=\"860\" srcset=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-02b.jpg 2000w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-02b-300x129.jpg 300w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-02b-1024x440.jpg 1024w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-02b-768x330.jpg 768w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-02b-1536x660.jpg 1536w\" sizes=\"auto, (max-width: 2000px) 100vw, 2000px\" \/><\/a><\/td>\n<td style=\"width: 50%; height: auto;\"><a href=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-03b.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-9027 size-full\" style=\"margin-top: 0px; margin-bottom: 0px;\" src=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-03b.jpg\" alt=\"\" width=\"2000\" height=\"860\" srcset=\"https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-03b.jpg 2000w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-03b-300x129.jpg 300w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-03b-1024x440.jpg 1024w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-03b-768x330.jpg 768w, https:\/\/cosmo.yerphi.am\/wp-content\/uploads\/2024\/12\/astr2-03b-1536x660.jpg 1536w\" sizes=\"auto, (max-width: 2000px) 100vw, 2000px\" \/><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 50%; text-align: left;\"><span style=\"font-family: arial, helvetica, sans-serif; color: #000000;\">Oscillogram of the tracking error and the corresponding image movement in the focal plane of the telescope in the guiding mode with only the secondary mirror (ASTRON system).<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; color: #000000;\">Tracking error &#8211; no more than <strong>\u00b10.3 arcsec<\/strong>.<\/span><\/td>\n<td style=\"width: 50%; text-align: left;\"><span style=\"font-family: arial, helvetica, sans-serif; color: #000000;\">Oscillogram of the tracking error of the developed iterative system and the corresponding image movement in the focal plane of the telescope.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; color: #000000;\">Tracking error no more than <strong>\u00b10.05 arcsec<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/td>\n<td style=\"width: 8%;\">\u00a0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; Lead designer A. Zakharyan &nbsp; \u00a0 In 1989-1991, right up to the collapse of the USSR, SKB Granit carried out work to create a precision guidance system for the large T-170 orbital telescope under the promising SPECTRUM-UV project, which<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_lmt_disableupdate":"no","_lmt_disable":"no","footnotes":""},"class_list":["post-7977","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/cosmo.yerphi.am\/index.php\/wp-json\/wp\/v2\/pages\/7977","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cosmo.yerphi.am\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/cosmo.yerphi.am\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/cosmo.yerphi.am\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cosmo.yerphi.am\/index.php\/wp-json\/wp\/v2\/comments?post=7977"}],"version-history":[{"count":0,"href":"https:\/\/cosmo.yerphi.am\/index.php\/wp-json\/wp\/v2\/pages\/7977\/revisions"}],"wp:attachment":[{"href":"https:\/\/cosmo.yerphi.am\/index.php\/wp-json\/wp\/v2\/media?parent=7977"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}