Synergous.com

I want to visit the Tracker Project Page. Read the rest of this entry »

Double Arm Drives have been used to photograph the night sky for over 20 years. Originally designed by Dave Trott, based on the Haig or Scotch mount (otherwise known as a Barn Door Tracker), the Double Arm Drive provides astrophotographers with a platform to track and capture images of celestial objects using slow shutter speeds, necessary for this type of photography. The proposed design, while conventional, attempts to refine the tracking performance of the double arm design. Hence, the Tangent Error Minimized (TEM) Tracker.

Several other means have been employed to reduce tangent error in barn door drives, such as the use of a cam or varying motor speed- which are very effective. The point of the Tracker design was to find a method of minimizing tangent error while retaining simplicity of construction and operation. The Tracker can be driven by hand, at a steady rate of 1 rpm, or by using conventional electronics. In this case, using a programmable microprocessor. A Google search should provide an array of designs to suit personal taste and technical capabilities, and is strongly suggested.

You may wish to consider the Tangent Arm concept, designed to convert an Alt/Az drive to an equatorial camera mount, or, simply mount it in a similar fashion to that shown for the Tracker.

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Note: imageJ cross platform image processing – Astro imaging tutorial.

First attempts with a Canon 1000D (DSLR). Some G9 images also. Exposures have been adjusted to remove the dull brown background of the RAW image, and further enhanced to reveal more detail.

Because the SCP is obscured from my viewing platform, polar alignment is achieved by bracketing the drift of a target star, in the region to be photographed, until drift is eliminated (see Tracker tutorial).

Less noticeable in wide field photography, altitude adjustment becomes more critical when using a telephoto lens. If altitude is set accurately, errors in azimuth will be evident by left or right drift only.

Leveling the device with a spirit level is generally not adequate to achieve accurate tracking, when using telephoto lenses, and drift must be eliminated by adjusting azimuth and altitude to compensate for minute error – a time consuming process.

One of the first. No correction except white balance with ufraw. Wide field - Sagittarius - Lagoon and Triffid Nebula - Canon 1000D, 55mm - 6 mins - f5.6 - ISO 400

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Intended to convert an Alt/Az mount into an Equatorial mount for astrophotography. The idea is to attach the Tangent Arm to the telescope mounting clamp, and use the computerised Alt/Az  to set Celestial North/South and the observing lattitude. The Alt/Az tracking function is not used. Read the rest of this entry »

Arduino Home Page

http://www.arduino.cc/

Arduino Suppliers

This ebay dealer, listed in Hong Kong, has a 100% rating, very reasonable prices and the lowest mailing / shipping costs I could find.

Advertised, the Arduino Duemilanive 2009 AVR ATmega168-20PU, is more suitable for beginners. This unit is now less expensive and still compatible with the Motor Shield used in the Tracker design. With on board USB, the Duemilanove circumvents the need for USB to Serial adapters, and other work, required, if using an Arduino Pro, for example.

I found this site useful for viewing a wide range of products.

The Arduino Pro, (two versions 3.3v and 5v) among other Arduino bits and piecies, may be suitable for a permanent installation. There is no on board USB and therefore requires a USB – Serial adapter, external to the board, and an FDTI cable.

I have been researching the history of HMS P48, a WW2 U class Submarine. Constructed by Vickers at Barrow, Inverness, P48 was assigned to the 8th Flotilla, in the Mediterraean, during Operation Torch, the invasion of North Africa. Historical setting – Casablanca – Humphrey Bogart and Ingrid Bergman – sets the scene.

Later, billeted to Malta, the P48 patrolled the Marrittimo line, but was lost to depth charges from Italian destroyers during an attack on an Axis (German and Italian) shipping convoy in the Straits of Tunis.

Today, the P48 rests at 200 meters, 16 nautical miles North West of Zembra Island, with its crew, including my Uncle, Able Seaman (Sound Detector) Reginald Meluish of Cardiff Wales – 22 yo.

If you have information about the P48, that you would like to share, possibly a family connection, I am very interested in hearing from you.

I wrote this several years ago, once I figured out how to get IR working. It was primarily aimed at Slackware users, and now includes ubuntu 8.10 and 9.04 (Jaunty).

IRDA (FIR mode) on Toshiba laptop with an smsc-ircc IrDA device and no BIOS setting. Read the rest of this entry »