Overview
Last updated
Last updated
CeruleanMap is used in conjunction with the CeruleanTracker application. It needs to run on the same network as the PC running CeruleanTracker, or on the same PC as CeruleanTracker. It is not intended to be an ROV operator’s main user interface.
Generally, the map app shows the position of the ROV, and also the location of the Topside GPS connected to CeruleanTracker, if there is one.
The map can also be decorated with known points and regions of interest.
When the CeruleanMap App launches, a control panel is shown on the display (see below). This is where the map is configured if you want it to run differently than the default. To put the panel away, de-select the “Show This Control Panel” checkbox, circled in, red. It will close and move the checkbox to the menu bar (see second figure, below, circled in red.
The control panel has options to turn various types of map decorations on and off. It also has an option to toggle lat/long displays between DD format and DDM format. There is an option to cache satellite imagery as well (see the section on satellite imagery below).
The map below is showing part of Wayzata Bay of Lake Minnetonka in Minnesota.
The map can be zoomed in and out with the mouse scroll wheel and can be dragged with the mouse to keep the area of interest in the display.
When connected to an ROV Locator Receiver set to track two ROVL transmitters, the CeruleanMap display will show a second ROV icon. The main ROV icon is a diamond shape and will be either red or yellow depending on which output you have selected in CeruleanTracker. The secondary icon is a violet square.
A few notes:
You can switch which ROV is primary or secondary in CeruleanTracker. Note that when you do this, it will greatly confuse any filtering done on the primary ROV position.
The secondary icon position is never filtered by CeruleanTracker.
The Edit menu has options to Erase the ROV trail. It can also clear any waypoints saved since the Console Application was started. This menu also has an option to copy the map window to the clipboard. Right-clicking the mouse in the map window also copies the map to the clipboard.
The Waypoint menu is used to add waypoints at the boat position or the ROV position. Waypoints can be saved to a file at any time. The file format is compatible with the map decoration file. Waypoints are named by date and time, but you can edit the names in the waypoint file after saving them. If you don’t save waypoints they are lost each time the program exits.
The map decoration file is assumed to be named “Known Points.txt” and is assumed to be on your desktop. The file can contain points of interest which are optionally plotted on the map with their names. The file can also contain polygons. Open polygons are displayed as piecewise line segments. These can be used as planned routed, boundaries, etc. Closed polygons are displayed as filled regions. They can be used to represent land, areas of interest, etc. Both Open and closed polygons are put into one of four color groups, which plot in that color. Each color group can be turned on and off separately.
The map decoration file is an ordinary text file.
The maps shown in this manual were decorated using the following file. Note some of the polygons show line wrapping so they can be seen on these pages, but you do not put line breaks in the file.
A polygon definition consists of the word “POLYGON”, a comma, a color group name (“BLACK”, “WHITE”, “BLUE”, “ORANGE”), a comma, and then pairs of comma-separated lat/long coordinates in DD format, with a comma following each pair except the last. For a closed polygon, the final coordinate pair needs to be exactly the same as the first coordinate pair.
The images on the next page are map displays of two DVL sorties of about 1500 meters. The total accumulated error is about 1.6% and 2.1% of total distance traveled. These images were not cherry-picked, but you should not expect to always achieve that accuracy.
The red trace is DVL dead reckoning with the sensor head mounted on a sting on the Cerulean RV Helter Skelter (see photos below). The green trace is ground truth from a GPS sitting about 1 meter away from the sting.
The course was over muck bottom with water ranging from 2 meters to 17 meters deep. There was submerged vegetation for about 25% of the course.
When operating in littoral areas the DVL Map window can load and display satellite images, either loaded on-the-fly from the internet (if you have internet access) or satellite image data cached ahead of time. It can do the same when you are in the deep ocean, but the images are, well, the ocean, so not that useful. Images are loaded from Google using Cerulean’s Google map API key. Google does not serve images at any useful level of detail for many parts of the ocean.
Radio buttons on the map control panel select the type of imagery to use. This defaults to “none.”
If desired, images are cached in a folder on your desktop called “DVLMapImageCache.” Each tile uses roughly 500 KB of disk space. Controls on the map control panel allow you to select the number of tiles horizontally and vertically, and the zoom level (resolution) for each cache operation. Multiple areas can be cached, and multiple levels of zoom (resolution) are also possible. Cached images are drawn first, and any known points or polygons will plot on top of the image.
The following screen snips illustrate the key aspects of the imagery feature.
