Monday, April 12, 2010

Reao Atoll FP - Finished . . . At Last!

Reao Atoll - Island Locator

Reao Atoll


Reao Atoll - ISS004 Image Mosaic (1-70,000)

Reao Atoll - ISS004 Image Mosaic (1:70,000)


Reao Atoll - EVS Precision Map (1-70,000)

Reao Atoll - EEVS Precision Map (1:70,000)

Reao or Natūpe is an atoll in the eastern expanses of the Tuamotu group in French Polynesia. The closest land is Pukarua Atoll, located 48 km to the WNW.

Reao is 24.5 km long and its maximum width is 5 km. The whole length of its north-eastern rim is occupied by a single long island. There is no navigable pass into the lagoon.

Reao Atoll's population is 344 inhabitants.

That is about it for Reao Atoll on the internet. There might be some scattered bits of information, but nothing of newsworthy significance. Why? It could be the location. Unlike many of the other atolls making up the Tuamotus that receive numerous pleasure cruisers, Reao Atoll is situated away from the normal cruising routes. In addition the lagoon has no entrance for sailing vessels making for percarious landings on and off of the main island.

Even with the geographical difficulties associated with Reao Atoll, I wouldn't mind visiting. The southern end of the atoll looks a bit on the wild side. If not real wild, it looks to be far from the population center of the island located on it's northern end. One could perhaps find an isolated small motu along the atoll's western edge. There are in the neighborhood of 50 motus along this edge of the atoll. I am certain one of these small motus could offer one a few days of solitude. If not a few days, for sure a few hours.

Now for a few comments on the map. First, the base imagery is from ISS004. I took 3 excellent images and assembled them into a mosaic of the entire island. I rotated the image about 37° to align it with the atoll's true alignment. I had created a shoreline of Reao Atoll a few years back, but had not saved the georectified image. All I had to work with was the island polygons which came from the ISS004 imagery. I used over 37 GCPs (ground control points) to georectify the ISS004 image mosaic. It wasn't until this weekend that I had both time and energy to complete my typical four vector layers - island polygons, vegetation polygons, shallow reef polygon and lagoon polygon. I completed all of the layers as Phil Mickelson was busy winning the Masters for the 3rd time.

P.S. - Later that day, I compiled my first OSM formatted vector file consisting of the island polygons. Ultimately my goal is to place my EVS copyright free vectors onto OpenStreetMap. That is another story for later time.