Home  |   Site Map  |  Contacts  |  Forums        Quick links: Data Browser Download Data Coordinates Time Series Map Browser Orbits SCOUT CRTN Velocity Maps SIM SITe Locate Site
All Arrays    |    PBO    |    Met Sites

SOPAC Online Map Interface (SOMI) Documentation

The SOPAC Online Map Interface (SOMI) allows users to compose, navigate and query various GPS-related information in a spatial context. Various components of this interface were built using the GD library, an ANSI C graphics library for fast image creation. View the GD Credits and License Terms here. Equally important in the creation of this interface is the ANSI C source code for GMT (The Generic Mapping Tools). SOPAC/CSRC would like to thank both providers for making available these software/libraries for public use. Map Navigation In this interface navigation is performed through one of three methods: recentering the map using the main map recentering the map using the supplemental context/inset map performing a scale change At any time you may recenter the map(s) by pointing and clicking on any portion of the visible main map, or context map (if it is active). The geographic location corresponding to the point on the image that was clicked will become the center of the next map, rendered at the same scale. Likewise, you may recenter the map to a specific location of your choice by entering the Latitude and Longitude of your desired location in the text boxes below the map. After changing these values you can either press <enter> on your keyboard or click on Refresh Map. Below every map the nominal scale of the rendered image is presented for your reference and/or modification. If you wish to simply change the scale of the current map, without affecting the location of the map center you can do so by either clicking on the Zoom Level controls to the left of the main map image, or by typing your desired map scale* into the box provided and pressing <enter> on your keyboard. * Note: There is a zone of scales where your changes will not take effect. This is due to current problems with using a Lambert Azimuthal Equal Area projection for extents only partially covering a hemisphere (e.g. "off the globe" area exists on the map). If your manual scale changes do not take effect, you must lower the value of your scale change and try again. Map Composition Each map rendered in this interface takes into consideration available map layers based on the current map extent and nominal map scale. Depending on these conditions certain map data sets will fade in and out of availability. The layers you have to chose from, at any time, are displayed in an interactive Legend to the left of the main map image.  Clicking on individual map layers will toggle their display between two states, on/visible and off/invisible.  Select All and Deselect All links are provided above the legend to aid rapid map composition. Each entry in the legend will indicate the type of data represented, the symbolization used to present the data and whether or not data/entities from the layer are queryable.  Layer entries with red/orange labels are designated as either queryable layers, or layers associated with a current user query. and : These two icons, only one of which is visible at any time, appear in the upper right-hand corner of the Map Legend component of the interface.  The "unlocked" state provide the user with all available map layers to choose from.  The "locked" state freezes the map composition as is, and displays in the legend only those layers currently set as "visible".  Some users may find this feature handy for creating slides for presentations and such.  If not, just leave the legend "unlocked" and you'll be fine. (Note: Currently the ordering of the map layers cannot be changed.) Map Size     and    Above the main map there are a set of map sizes from which you may select. These sizes correspond to the relative size of the main map image and can substantially improve (or hinder) map refresh/build rates.  Furthermore, there is a Big Plot icon above the main map which will create, in a new window, a very large map using the user's current layer choices and composition parameters. (Note: Big plots present a much larger geographic extent than what is typically presented in the main interface.  Please be patient when using this option as map rendering times can increase substantially depending on map scale and composition.  Also, please note, big plots no longer have any interactive functionality - they are completely static.) Map Query & Export On the right-hand side of the map interface there is a Query & Export toolbox provided to aid users in their search for particular information/data of interest.  This toolbox is linked to a "shopping cart" on a host-by-host basis.  This shopping cart can be populated using spatial filters specified by the user, and executed by the user when they choose to do so.  Currently users may add (+) map entities to the cart by clicking on specific entities on the map itself, or by specifying a query center point and kilometer buffer (Search Radius), or by specifying a Bounding Box (north, west, east and south extents).  Entities may be removed by any of these same methods, by changing the Mode to (-) Remove and performing the same procedures.  However, individual entities may also be removed from the cart by name using the Review mode at the bottom of the Query & Export toolbox, and selected individual entities to remove by clicking on their respective icon. The tools in this component of the interface were designed to help the user rapidly identify points of interest in an interactive, geographic context.  If there are other methods you would like to see made available, or modifications made to the current tool set, please let us know.  We would be happy to receive your feedback. Velocity Toolbox This component of the map interface is specific to GPS Velocities.  The user is provided with the ability to add GPS Velocity "layers" to their map (and legend) based on a Reference Frame of their choosing (from the provided list), or using a single reference station/site from the user's shopping cart.  The resultant layers can then be turned "on" or "off" in the main map legend like the other map layers.  Symbolization and a name for each layer is automated generated by SOMI and cannot be modified (currently).  Display of Error ellipses, GPS station names, and the length (2-dimensions) of the vectors (for ALL velocity layers in the map) can be toggled using the controls in this toolbox. Note: Currently you may add up to 10 new GPS Velocity layers to your map session. Note: Generation of velocity map layers based on a single reference station is a new feature of this interface. Currently this functionality can only be performed by only having one station in your shopping cart at the time of frame definition. This is achieved in one of two ways: 1) 0 stations in cart - Ensure query and export Method is Mouse Click. Choose Custom from cart choice in reference frame menu in Velocity Toolbox. Use your mouse to select the station you wish to use as reference. The new layer will be generated. 2) 1 station in the cart - Choose Custom from cart choice in reference frame menu in Velocity Toolbox. Then click Refresh Map button below main map. The new layer will be generated.