www.astrocafe.hk

Dear all,

Just finished the webpage on Roll-off Roof setup.
See here at :-
http://www.raymondtse-lawyer.com/astro/ ... atory.html

Thanks for watching.

Raymond Tse

謝謝分享，你的天文台比我在西藏的還要多些配置。

好奇請教一下，你的赤道儀如何實現Home的?

Dear Savio,

For remote operation, EQ6 Pro with EQ Mod has a parking function from its interface at Sky 6 to park at home,
ie the Polaris/North position. The initial manual alignment to Polaris/North is only done by hand and may not be accurate.

Then at Sky 6 EQMod interface, unpark & track, go-to a bright star.
Make the fine centre-adjustment of that star by electronic finder. Then sync at EQMod.
Then park again to home. I assume this 2nd time computerized home parking would be more accurate.

Unlike ME with hardstop homing, EQ6 Pro may hang around if there is power failure during go-to or imaging.
I suppose the web power switch (connected to UPS) has to be connected to the EQ6 Pro mount
to prevent sudden power failure.

Raymond Tse

Thanks!

我稍後也打算加些設備到西藏天文台，因為目前只有一台自動化天文台。手上有一套Celestron Ultima Equatorial Fork mount，是用高精度Byers渦輪的，帶PEC功能及一顆9V電池可以運作數晚，按理拍廣角星野很方便，但要改動作遙控會很煩。

你暫時應主力拍深空吧? 或有其他觀測計劃? 這問題看似無聊，但我的確想過在香港裝個遙控天文台拍月面行星的。

Dear Savio

The main advantage of Roll-Off is its bigger area (compared to dome),
and thus there are some flexibilities of adding 2 to 3 sets of imaging setup
for different purposes.

I started off with deep sky imaging in the wild dark sites and many old gears purchased over the years
(shown in the pictures) are tipped in favour of long exposures eg, FF, AO, filter wheels, still-image cooled CCD.

However, clear night skies are rare in Hong Kong and Sai Kung is famous for gathering clouds.
After this deep-sky setup, I shall set up daytime solar Ha video capture using Lunt 152 F6
(bought from you) with either mono or colour ASI CCDs.

With these 2 setups, my Roll-Off will become congested for the 3rd Moon/planets setup using 12.5 inch dob on
EQ platform, but this will initially be manual instead of remote operation, unless I add ServoCat for auto slew.
But remote operation for high power Moon/planets on platform (instead of high loading ME2 class) may be frustrating.

2 to 3 birds by 1 stone ?

For now, just concentrate on something on hand. I have already spent too many hours just in configuring too many gears at the
same time. Some of my gears are just colllecting dusts

Raymond Tse

Raymond TSE 寫:Dear Savio

The main advantage of Roll-Off is its bigger area (compared to dome),
and thus there are some flexibilities of adding 2 to 3 sets of imaging setup
for different purposes.

我很同意ROF及圓頂是各有千秋的，97年拜訪過廖興齊先生在加州的ROF，內有Astrophysics的8" APO折射及Astrowok的12" Maksutov，後來更震撼的是德國Markus Ludes的ROF，內有APM 254APO、Fujinon 25x150ED 雙筒、全球最大的UHC濾鏡、Carl Zeiss 180 Maksutov、Starmaster 24" Dob (極高Strehl的).... 都是各自範疇內最頂級的器材：

viewtopic.php?f=13&t=85

我個人喜歡Dome的原因是防風防露，也真的有一種完整保護的感覺，加上個人取向是集火力在一兩台器材上，所以Dome是方便些。

Raymond TSE 寫:I started off with deep sky imaging in the wild dark sites and many old gears purchased over the years
(shown in the pictures) are tipped in favour of long exposures eg, FF, AO, filter wheels, still-image cooled CCD.

However, clear night skies are rare in Hong Kong and Sai Kung is famous for gathering clouds.
After this deep-sky setup, I shall set up daytime solar Ha video capture using Lunt 152 F6
(bought from you) with either mono or colour ASI CCDs.

可以想像，日後好天時那裡會很熱閙，坦白說，現在搬到辦公室附近，沒有了以前的私家天文台，效率是低很多的，就算開車去白鷺湖天文台就是10分鐘多點，但仍遠不及自家天台的高產及方便，尤其當我只需要短時間做些測試時，根本無可能把大量器材搬出去重新架起來測試數分鐘，過去一兩年，我在西藏的天文台所有器材都當時的自家天台測試才發到西藏運作，現在就麻煩多了，手上那個彗差鏡本來拿上天台十分鐘便測完，現在要花時間到白鷺湖天文台弄半晚才成。

Raymond TSE 寫:With these 2 setups, my Roll-Off will become congested for the 3rd Moon/planets setup using 12.5 inch dob on
EQ platform, but this will initially be manual instead of remote operation, unless I add ServoCat for auto slew.
But remote operation for high power Moon/planets on platform (instead of high loading ME2 class) may be frustrating.

2 to 3 birds by 1 stone ?

For now, just concentrate on something on hand. I have already spent too many hours just in configuring too many gears at the
same time. Some of my gears are just colllecting dusts

Raymond Tse

有時我想，一台300以上的大牛反配一台中口徑如130級的折射，配些週邊器材如相機、日珥濾鏡，或可滿足大部份人的要求，現在ME2比之前一代負重大幅增加，又可越過中天3小時，的確是好事。

I do not live near the observatory. Still require 45 min to 60 min drive from HK to Sai Kung.

To avoid driving there just to view the clouds, I have to setup remote operation to save some time.
Home roof observatory will be better suited for Moon/planets where light pollution is lesser of a problem,
but not deep sky, unless your whole family can tolerate the long distance driving.

Raymond Tse

我想你早晚要實現全遙控操作了

Dear Savio,

Are you using ACP-3 for fully automatic operation (no need to check cloud coverage, no need to check all-sky cam at all) ?
Then you don't have to wake in the middle of the night to check whether the clouds have been clear.

Raymond Tse

I have two Boltwood Cloud sensor and one self-built all sky cam on site,

viewtopic.php?f=20&t=1389&start=140#p21987

with Boltwood Cloud Sensor, ACP works very well.

Adding Daytime Test Run video of remote operation of observatory.
http://www.raymondtse-lawyer.com/astro/ ... atory.html

The video was taken on site via a computer inside the Observatory's control room.

Raymond Tse

精采!

想討論一下：

1. Flip-flat ：我在西藏不用這東西的，Park 的時候乾脆把鏡放平，鏡頭一直很乾淨，我是用Sky flat的

2. 掛線：望遠鏡赤道儀有機會被那些線跘著，可能要想辦法整理一下了

3. Guider：Piggy back在望遠鏡上那是導星或廣角取景器或攝星野用的? 若是導星用很大機會有flexure

4. ROF 向南趟?：我現正設計304APO雙筒用的ROF，要麼向北趟開，或者東西走向，那是從視野及散熱考慮

題外話:

想請問 ACP 能否控制 Roll - off roof? ACP 好像只控制 ascom 標準配件，而 Roll off roof 好似是用普通電機加控制器，所以 ACP 能否控制成疑問？

另外 ACP 是否能控制 mount 及 roll-off roof 有 delay timing? 如果 cloud sensor 放出 signal 要關 Roll off roof，而 Mount 仍未在 parking position；這樣有可能碰撞了。 請各位高手指點迷津!

funoooo 寫:題外話:

想請問 ACP 能否控制 Roll - off roof? ACP 好像只控制 ascom 標準配件，而 Roll off roof 好似是用普通電機加控制器，所以 ACP 能否控制成疑問？

另外 ACP 是否能控制 mount 及 roll-off roof 有 delay timing? 如果 cloud sensor 放出 signal 要關 Roll off roof，而 Mount 仍未在 parking position；這樣有可能碰撞了。 請各位高手指點迷津!

1. 可以，用一片MaxDome版便可以，但摩打最好是直流的，並有儲電池作緩衝，因為停電跟電腦斷線也是關趟頂的條件之一，那時儲電池便很重要，有丁點電力可以關上趟頂便一切好辦

2. 問題是Cloud Sensor因天氣狀況發放訊號至MaxDome的Aux input，這過程是完全獨立於ACP的，或應該說，ACP是被知會而已，所以無能為力，這也是安全考慮，因為Cloud Sensor及MaxDome可以在電腦當機或停電下運作，也必要這樣才能保障天文台安全。

我是這公司的代理，不時賣Cloud Sensor, MaxDome，甚至MaximDL 也可以

http://www.cyanogen.com/

社長 寫:精采!

想討論一下：

1. Flip-flat ：我在西藏不用這東西的，Park 的時候乾脆把鏡放平，鏡頭一直很乾淨，我是用Sky flat的

2. 掛線：望遠鏡赤道儀有機會被那些線跘著，可能要想辦法整理一下了

3. Guider：Piggy back在望遠鏡上那是導星或廣角取景器或攝星野用的? 若是導星用很大機會有flexure

4. ROF 向南趟?：我現正設計304APO雙筒用的ROF，要麼向北趟開，或者東西走向，那是從視野及散熱考慮

1. Cover is always better than none. Sai Kung is a quick-rain place. If for whatever reason the roof cannot close during rainpour, I
can still close the cover to minimize water seep-in. Besides, a lot of dust will be gathering on the glass surface especially with humid
moisture. My APO scope metal surface has already gathered a thin coat of dust. Something will not happen in Tibet :- birds' dropping,
spiders' web and now lots of dead bees' bodies.

Sky flat is feasible for automated flat field imaging when sky is clear all night/day long in Tibet. In HK, you are lucky to get 2-3 hrs clear night sky,
usually cursed by lots of clouds' coverage afterwards. Taking sky flat in most cases is impossible in HK.

Even if you are lucky with clear sky at dawn, all you want is to to is to sleep rather than to wake up early in the morning to wait for
sufficient lighting for flat field. The light intensity changes rapidly during dawn. You have to decrease exposure time to achieve similar
light flux. Very challenging job when I tried to do it once/twice in the past.

I also have 2 standalone EL panels (A3 size and 6 inch sq) but to place it orthogonally towards the scope would be difficult for EQ mount.
1 side of EL panel will be nearer while the other side will be further away. Light will therefore be of different intensity to the scope.

An EL light panel attached to the Flip-Flat simplifies the job. Dusts may gather on the glass or filter wheel or CCD at different times.
The best flat field should be done immediately after each imaging session.

2. Wiring will be grouped later to avoid tearing.

3. The piggy back is electronic finder. The FOV of ST402+EF 50mm is about 8 x 5 degree to help align/syn when go-to is not spot on, since
my main CCD Atik314L wih 980mm focal length has a narrow FOV. While not a video camera, ST402 can refresh quite fast with PHD software
to be used as a slow-frame rate video finder.

Of course, I can change the lens to 35mm or wider for wide field imaging but I require focusing robofocus motor to the lens pljs ST402 filter wheel
in order to take RGB. May consider to change ST402 to Q8 for one shot colour wide field.

The actual OAG guider after AO is Lodestar, which should be sensitive and light weight for SX AO.

4. ROR south opening is to cover the fibreglass house which is placed in the South to block the neighbouring house attached to my house
(twin village house). My neighhour has flood lights for their rooftop jacuzzi and BBQ. To avoid distraction of their young ladies with bikini
at the jacuzzi, I place the fibreglass at the south side to provide privacy/light blocking for my observatory.

With the larger roof panel, my south side open dimension is reduced from 12 feet to 9 feet, still enough for testing out the automated observatory.
However, the south elevation is about 30 degree even after my high metal pier of 4 feet high.

May be I can consider to order a metal pier of 5 feet of higher to have a wider aperture for my Lunt scope.

I have the darkest view at the East side and some urban light pollution in the West. If I were to redo the whole project again, I would open the roof westward.

A more seriouis imaging location close to HK should be at He Huan Hill in Tai Chung, Taiwan. Short flight there. Next dream.

Raymond TSE 寫:
A more seriouis imaging location close to HK should be at He Huan Hill in Tai Chung, Taiwan. Short flight there. Next dream.

這個帖夠參考價值了

- 我也想過做dome flat，東西也買好了放在西藏，但每次上去都不想動，最關鍵的事情辦了便急著回香港，可能是高原缺氧關係，或許應叫高海拔懶惰症...

- 有機會試試SBIG STi，我會說是SBIG成立廿年來真正做得好的導星器，輕巧也僅用USB便可連接電腦同時供電運作，因為我猜你根本不會用ST402這麼低解像度的相機來拍星? 這個我以前用過的，現時西藏的Paramount ME也三年前是用它來做PEC training的

- 以我對台灣有限的認知，能建私人遙控天文台的地點大都不是建台的好地方，因為台灣可以建私人設施的土地，最高也只有2000米海拔，偏偏2000米上下那個高度是最麻煩的，雲霧都積在那裡。當你在清境觀星園每晚賭運氣可能有一半時間"騰雲駕霧"，架起器材雲霧來了，收起東西天又清，但我可以七天六夜上武嶺全部晴天，分別只是當晚八、九、十時雲霧全部退到山下去。我對陰那山有保留也是基於這原因，因為那海拔實在太尷尬了，要麼3000以上，要麼乾脆離開那座山。在香港大帽山雖不算高，但也有不時烏雲蓋頂。

- 西藏的分別是，相對於大部份都在主要的雲底工作，我是在雲頂工作，除了Boltwood Cloud Sensor的系數要調一下外(在平地用原有設定還是十分精準的)，最重要的特色是天氣穏定得多，大多情況下要麼整晚晴天，要麼整晚陰天 (當然晴天率亦很高)，十分清脆利落，不會拖泥帶水，有如我在武嶺的情況。

http://sphotos-d.ak.fbcdn.net/hphotos-a ... 3479_n.jpg

Dear Savios,

Tibet 5K altitude is of course the 1st choice for remote. You are lucky to set a foot there.
Xin Jiang Gaoxhing & Carl Chan are also lucky guys to set up at Xin Jiang site, while Angus Lau has also set up in NSW, Australia.

All of these premium sites have their competitive advantages and strengths.

I also know of Taiwan land limitation and Guan Xin Yuan might be the highest altitude for human habitation at this moment.
There are some houses/farms just next to Guan Xin Yuan. Don't know whether we have the chance to buy a small piece of land there.

Sadly enough, I have to wait for retirement/semi-retirement before I have the time to set up any remote site abroad.

Raymond TSE 寫:Dear Savios,

Tibet 5K altitude is of course the 1st choice for remote. You are lucky to set a foot there.
Xin Jiang Gaoxhing & Carl Chan are also lucky guys to set up at Xin Jiang site, while Angus Lau has also set up in NSW, Australia.

All of these premium sites have their competitive advantages and strengths.

I also know of Taiwan land limitation and Guan Xin Yuan might be the highest altitude for human habitation at this moment.
There are some houses/farms just next to Guan Xin Yuan. Don't know whether we have the chance to buy a small piece of land there.

Sadly enough, I have to wait for retirement/semi-retirement before I have the time to set up any remote site abroad.

有一位Astrocafer也在台灣高山建立了自己的遙控觀測站，你搜搜帖子便知道，或者有機會交流一下。

對我來說，在機會面前不敢猶豫，所以在財務及時間上，兩年前投入建立西藏天文台肯定比以後幾年才做的代價大得多，但事後證明，今天站上已很難再容下另一個私人觀測站了，因為在有限的土地上已預留空間給各大學及機構建台，也不便加入一些小型私人設施，以免造成不必要的問題，要知道西藏是一個敏感的半軍事區，我很清楚自己獲批在那裡建台，也應安守本份，只會做天文觀測，無興趣從事任何其他事務。

我不認為以自己的水平來說，西藏或新疆天空會有什麼分別，兩片都是極品的好地方，也相信將會出現極高水平的觀測成果，但兩地也各有自己的限制，例如新疆的冬天會嚴寒些，緯度也高十多度，西藏氣候温和些，可觀測南方天空多些，但每次去也有高原適應時間，物質條件也惡劣些。

回首10年，自己承接的多個本地及海外項目，大部份機會都是閃瞬即逝的，當時台灣大學在西藏的天文台，又或者剛完工的全球最大APO雙筒鏡，也是一通電郵一個電話就落實了，我甚至不敢想像，若當時拒絶了這些機會，會是多大的遺憾，當然也要感謝他們的信任

Dear all,

Despite the foggy sky, it is good time to test run the remote operation during Moon age 25 when the sky is fine.

The guide camera Lodestar's focus is off when the main imaging scope is being focused remotely. No way to adjust the manual focus.

Would try unguided 2 min exposure each.

Raymond Tse

我的自製導星器，是讓SBIG STi在濾鏡前導星，所以甚少處於最佳焦準，被導星也基本不會成圓點，但從來不愁找不到導星，視寧度好的，導星精度RMS更在0.3"水平，無論單幀30分鐘或60分鐘，都不會拉線，以650mm焦距來說，是很不錯的。

viewtopic.php?f=20&t=1664#p22277

viewtopic.php?f=29&t=2884#p19896

為免Guide on seeing，我是設定曝光5秒的，現在為提升效率，減少每張照片的成本，才改為3秒，一樣不管什麼天區，都在像場內隨時有三五七顆以上的導星可選。