update docs with new stationkeeping time considerations for CTD, Drifters, Argo floats

Author: j-atkins

docs/user-guide/assignments/Research_proposal_intro.ipynb

@@ -89,9 +89,13 @@
     "\n",
     "Throughout a CTD deployment, the research vessels needs to stay in the same location. To calculate the time needed for a CTD deployment, take the following information into account:\n",
     "\n",
-    "* Add time to lower the vessels speed to zero and set the vessel to the appropriate direction against swell, current, wind, etc = 10 minutes \n",
+    "<!-- TODO: this should be updated when the time is calculated as depth dependent (see [#249](https://github.com/Parcels-code/virtualship/issues/249)) -->\n",
+    "* Add time to lower the vessels speed to zero and set the vessel to the appropriate direction against swell, current, wind, etc = 15 minutes \n",
     "* Add time to deploy the CTD, and to recover = 10 minutes (2*5 min) \n",
-    "* Add time for the way down and up, usually at 1 m/s (winch capacity) = twice your maximum depth (in seconds)\n",
+    "* Add time to raise the CTD down and up, usually at 1 m/s (winch capacity). We make an assumption in VirtualShip that the average CTD downcast/upcast takes 15 minutes.\n",
+    "* Add time to speed the ship back up again and set course to the next waypoint = 10 minutes\n",
+    "\n",
+    "In total, therefore, you can expect a CTD deployment to take approximately 50 minutes.\n",
     "\n",
     "<iframe width=\"560\" height=\"315\" src=\"https://www.youtube.com/embed/7N2UsPDczTw\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen></iframe>"
    ]
@@ -104,7 +108,7 @@
     "\n",
     "A surface drifter is an oceanographic instrument used to study surface currents and ocean circulation patterns. These devices are designed to drift passively with the surface currents while transmitting data on their position and sea surface temperature.\n",
     "\n",
-    "You may assume it doesn’t take any time to deploy drifters.\n",
+    "You should assume it takes a combined 20 minutes to both slow down and speed the ship back up, in order to safely deploy drifters from the ship. Make sure to account for this time in your planning.\n",
     "\n",
     "<iframe width=\"560\" height=\"315\" src=\"https://www.youtube.com/embed/3m_CxEE8Bhs?si=XdyMFAVq9RVxQdcE&amp;start=15\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen></iframe>"
    ]
@@ -119,8 +123,8 @@
     "\n",
     "The floats periodically descend to a predetermined depth, typically around 1000 meters, and then ascend to the surface, measuring temperature and salinity profiles along the way.\n",
     "\n",
-    "You may assume it doesn’t take any time to deploy Argo floats.\n",
-    "\n",
+    "You should assume it takes a combined 20 minutes to both slow down and speed the ship back up, in order to safely deploy Argo floats from the ship. Make sure to account for this time in your planning.\n",
+    "    \n",
     "<iframe width=\"560\" height=\"315\" src=\"https://www.youtube.com/embed/IgcYQML5se4?si=Y7m1kLqUl14QZfcd\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen></iframe>"
    ]
   },