It’s not just a job…it’s an adventure
I had a recent project to establish LiDAR control for all of Puerto Rico and the US Virgin Islands. My part of the project was to do the three US Virgin Islands, as well as the Puerto Rican islands of Culebra, Vieques, and Mona. And then do some work on the main island to supplement what my employee was doing there. Total of 241 points, 200 on the main island.
Day 1: landed in St Thomas, setup a base, surveyed on St Thomas using RTK over cell.
Day 2: ferry to St John, used the same base on St Thomas, surveyed points on St John, then returned to St Thomas and flew to St Croix, setup a base there, and surveyed points. Had to do static on one point due to no cell.
Day 3: completed survey on St Croix, flew to San Juan
Day 4: flew to Culebra, surveyed on Culebra from a temporary base. Here is the approach into Culebra, which the pilot warned us would be a bit steep.
https://youtube.com/shorts/YbGNVyIgp9I
Day 5: flew to Vieques, surveyed on Vieques from a temporary base
Day 6, 7, 8: surveyed points on main island of Puerto Rico using VRS. Very difficult due to narrow roads and jungle foliage
That left the island of Mona. A permit is required to visit the island, which is controlled by the Puerto Rico Department of Natural and Environmental Resources. Access is by boat. A few rangers are stationed there, and hunters are there this time of year. I got a quote from one of the charters in the area. $5000. an extra $1000 if we got stuck there overnight due to weather. Seemed excessive. And the seas can be rough, it is located halfway between the western side of Puerto Rico and the eastern tip of Dominican Republic.
On my flight to Vieques there was only one other passenger, and he was familiar with Isla de Mona. He said that the Puerto Rican DENR flies a plane out there every Wednesday to swap out rangers and to take food, etc.
That led to me chartering a flight from the company that does it for DENR. The DENR has a Cessna Caravan, but it is getting its engine overhauled so they charter an Islander every week from Air Flamenco. Because I needed to be there several hours to survey, I could not go with them on the Wednesday flight. So I set it up for a Thursday a couple of weeks ahead. A bit of a risk because they can only fly VFR. And I didn’t yet have the permit. Normally visitors are only allowed to come by boat. A hunter was lost on the island, so they were hesitant about the permit. Had to get a flight manifest, get the USGS involved, etc. I flew to San Juan the day before my scheduled charter flight . and only got the permit finally approved as I was on my way from Charlotte.
The next morning I took an uber over to the downtown airport and we took off about 7 AM in an Islander (twin engine). We flew along the north coast of Puerto Rico for about 40 minutes, and then across the open water. The approach and landing to Mona was pretty cool.
When we landed, nobody was around. So we walked about a mile to Sardinera Beach where the rangers lived. They said all of their vehicles were down, so that was why they didn’t come to meet us. On the walk I saw a few 4 foot Mona Iguanas, one was really close…
I had to survey 5 points there, plus I occupied a tidal benchmark that also had an OPUS share solution. I did an RTX occupation on that mark, which was 975 9938 A (PID DN8586). It is at the far left corner of this pier on the west side of the island.
Once I transformed the ITRF position to NAD83 (2011) epoch 2010.0 it hit the OPUS SHARE solution under 2 cm horizontal and -3 mm vertically on the published PRVD02. After that I surveyed a few points at the far end of the runway, and found that there is a CORS on the side of the runway. Everything I could find says it was decommissioned, but it looks like it is functional, grass was mowed, solar panels looked good, satellite comms looked functional. But I couldn’t find any current data, so I wound up using one CORS in the Dominican Republic and two in Puerto Rico to position a base that I setup.
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