During these years, the European powers were fighting each other in addition, England was unsuccessfully trying to put down the upstart American rebels. Thousands of tons of commodities are traded daily in a colorful, noisy, bustling town, with hundreds of small boats going from ships to shore. Goods are available here from all over the world: fine fabrics, silver, gold, household supplies, slaves, guns, sugar, tobacco, and cotton. All along the shore a sea wall protects a long street of shops and warehouses. From one to two hundred sailing ships lie at anchor. Imagine now, the Golden Era during the mid to late 1700s, when Statia was the trade capital of the Indies. Ashore, a donkey grazes peacefully little movement breaks the tranquility. To the east a perfect volcanic cone rises to 2000 feet. On top of the cliff the present small town peeks out through trees. At the base of the cliff a couple of buildings are nestled between old stone ruins, which tumble into the sea.
From the anchorage you will see a long cliff just behind a sandy beach.
This makes the image much easier to read when alignment is very close to perfect.Statia is a small island with a large history. I extend this to 70 seconds and add the extra time to the second slew. DARV uses a 65 second exposure to get a 60 second drift measurement. I've found that with mounts in the under $5000 price range, a one minute drift portion of the DARV measurement yields results that are slightly more accurate than the minimum mount adjustment to correct for drift. If you are doing a drift alignment to support imaging, you can use the DARV technique to measure drift with your imaging camera. PHD2 also knows the DEC where the drift alignment was performed and adjusts the amount of correction needed as the declination changes when you switch targets. This is greatest at the celestial equator. Drift is measured by N-S movement of the alignment star over the physical distance the the star travels in the FOV during the measurement interval. Drift alignment when guiding with PHD2 (or the older PHD) should always be done at or very close to the celestial equator.
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