#California geotiff maps software

#California geotiff maps software

FieldMove and Move software support basemaps to zoom level 20. CalTopo supports exporting images to zoom level 16. Some generalizations based on maps centered on the equator are provided in the table below. Although this means the pixels per meter depend on latitude and the map scale depends on the pixel size/density of the viewing screen. Notice the steep climb of the number of tiles as zoom level grows (and file size correspondingly). A tile is a square raster image 256 pixels by 256 pixels. MBTiles work off the principal of a map zoom level, which is defined by the width a 256 pixel wide map is in degrees longitude. The advantage of this file format is that only the imagery within the current map view is loaded (and at the appropriate scale), making for much more efficient basemap loading in FieldMove. Many web-based map applications use MBTiles for its efficiency such as Google Maps (with slow internet connections you will see the map area load square by square). This file structure allows you to customize what is visible at different map scales to ensure the best balance of resolution vs. As the name suggests, this single file is actually a database of smaller raster images that are referenced to each other according to a tiled mosaic.

MBTiles: MBTiles is the preferred file format, though in some cases may require an additional step to prepare (such as converting from a GeoTIFF file).

I would not recommend importing GeoTIFF files larger than about 350MB each. This can lead to slow basemaps load times, especially initially. A key disadvantage of this file format is the often large file size for map areas and the fact that FieldMove will try to load the entire file at once (not just the portion visible in the current map view). These files are typically easy to generate (e.g. It is essentially a TIFF image file with georeferencing information embedded in it (projection, coordinate system, extent, etc.).

GeoTIFF: GeoTIFF is a fairly standard file format which can be read by most GIS software packages including ArcGIS and Google Earth Pro.

Two raster-based file types are supported for importing, GeoTIFF and MBTiles. Note that FieldMove does not currently support vector-based file types for import. For the iOS case described here this means using iTunes as the bridge between your computer and iPad. Arguably one of the most important features of FieldMove is the ability to import your own basemaps. This method works great as a 'quick-and-dirty' option, requiring little time or setup! I usually make sure caching imagery is the last thing I do before heading to the field and then leave my iPad on Airplane Mode. Note in FieldMove's Settings menu there are relevant options for basemap loading and cache resetting.

Then double-check that when you turn off the WIFI the imagery is still visible (this indicates it is temporarily stored, and will remain stored until you clear the cache or overwrite it by loading other areas after). Repeat this procedure with the other imagery types for the same area if desired. Repeat this until you have covered the entire field area. Once the imagery for this area is loaded (clearly visible), move to the adjacent area and let that load.

To cache imagery you should zoom on the map to the maximum imagery quality that you desire. Google Earth and most web browsers operate similarly. Think of the cache as a rolling temporary memory- once the cache limit is reached the most recently viewed imagery overwrites the older imagery. If these three layer options are sufficient for your mapping needs and the field area is not overly large, you can temporarily 'cache' the imagery to the iPad's internal memory.