ChartTiff NxGen Geos   ChartTiff NxGen Geo and DRG Dataset
  NextGen Geo / DRG Quads
 ChartTiff's Next Generation of Topographic Maps are generated from USGS GeoPDFs

ChartTiff NextGen Geo (GeoPDF to Geotiff) Collarless / Seamless USGS Topo Topographic Maps
O40105c2 (Carter Lake, CO)
ChartTiff NextGen Collarless / Seamless Geo

   ChartTiff's Current NextGen's are generated from the latest, 2014 or Later,
   Digitally Generated USGS GeoPDF Topographic Maps.  ChartTiff offers all Historical GeoPDFs
   (since 2009 inception) Digitally Generated USGS Topographic Maps as GeoTiff / JPEG NextGen's

   NextGen Geo's are Collarless / Seamless Topographic Maps
       No Setting Clipping or Setting a Transparency Layer required
       Plug compatible with your GIS System

   NextGen DRG's are Collared Topographic Maps

   Complete coverage of the US, Hawaii, Puerto Rico and Virgin Islands
       Currently only partial coverage of Alaska

   All States are 1:24,000 Scale Files
       Except for Puerto Rico and Virgin Islands that are 1:20,000 Scale
       and Alaska that is 1:25,000 Scale

  Projection information is selected during Check Out
     Select UTM, State Plane, Latitude / Longitude or Web Mercator Projection
       The projection information applies for complete order
       If multiple projections are required please submit multiple orders

  Select Output Resolution during Check Out
       (600, 500, 400, 300 & 250 DPI Available)
       600 DPI Produces largest file size
       250 DPI is Compatible with Original Scanned Geos

  Optional Layer Selection during Check Out
       Select only the layers that you want represented on the map
       User will receive:
           1 composite map with selected layers
           Individual maps with each selected layer
           1 composite map with all available layers
       Applies to Individual and Custom Area NextGen's

  Standard GeoTiff format enhanced with ChartTiff Extensions
       Plus ESRI "tfw" and MapInfo "tab" files
       Optional JPEG format -- Selectable at Check-Out

  User can add Shaded Relief to NextGen Geo's and DRG's during Check Out

  User can select ChartTiff Enhanced Collars for NextGen DRG's during Check Out

  A NextGen Geo or DRG Quad is available as 1 Free Download

  ChartTiff NextGen Geos and DRGs are sold by:
Current NextGen Topo Maps Revisions

ChartTiff GeoPDF to GeoTiff (NextGen Geo)  Revisions

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023

Original USGS Topographic Maps ChartTiff Geo Collarless / Seamless USGS Topo Topographic Maps
Normal USGS Topographic Maps With Collars ChartTiff Geo's Without Collars
  • A ChartTiff Geo map is created from the a USGS DRG topographic maps.

    The quad is first projected to your requested projection, then cropped to the map extents.  The voided areas of the map are then filled with the necessary adjacent map information to make the map and Tiff file rectangular.

  • All ChartTiff Geo raster images are geometrically registered at the pixel level from map to map; even from degree to degree.

    All ChartTiff Geo raster images allow for easy panning from one map to another, without worrying about map overlap and transparency problems associated with other map products.

  • The Tiff files are then enhanced to the ChartTiff format with additional tags.
    ChartTiff is a superset of the GeoTiff standard.  ChartTiff Extensions and Tiff Documentation
QUAD Naming Convention

The Quad name format was developed by the USGS and is used to specify the geographic location of a quad map in latitude / longitude coordinates.  For example, for quad name O34119d6, the letter "O" specifies the map scale 1:24,000.  The number 34 specifies base latitude of 34 degrees, and the number 119 specifies base longitude of 119 degrees.

Each 1:24,000 map location is 7.5 minutes by 7.5 minutes; which equates to 8 x 8 = 64 quad locations in a 1 degree by 1 degree square of geographical area.  The 8 rows and 8 columns of quad locations within each square degree are designated by the last 2 letters of the quad name.  In this example (O34119d6), the quad is the fourth row (the letter 'd'), and sixth column (the digit '6').  Rows are designated from 'a' (south-most) to 'h' (north-most), and columns are designated from '1' (east-most) to '8' (west-most).

The 64 quad locations for the example are:

  Latitude 35  


h8 h7 h6 h5 h4 h3 h2 h1
g8 g7 g6 g5 g4 g3 g2 g1
f8 f7 f6 f5 f4 f3 f2 f1
e8 e7 e6 e5 e4 e3 e2 e1
d8 d7 d6 d5 d4 d3 d2 d1
c8 c7 c6 c5 c4 c3 c2 c1
b8 b7 c6 b5 b4 b3 b2 b1
a8 a7 a6 a5 a4 a3 a2 a1



Latitude 34


The following table lists the partial degree
values for the bottom (south) edge
of each quad location:

  decimal minutes/seconds
a 0.000 00' 00"
b 0.125 07' 30"
c 0.250 15' 00"
d 0.375 22' 30"
e 0.500 30' 00"
f 0.625 37' 30"
g 0.750 45' 00"
h 0.875 52' 30"

The following table list the partial degree
values for the right (east) edge
of each quad location:

  decimal minutes/seconds
1 0.000 00' 00"
2 0.125 07' 30"
3 0.250 15' 00"
4 0.375 22' 30"
5 0.500 30' 00"
6 0.625 37' 30"
7 0.750 45' 00"
8 0.875 52' 30"


ChartTiff maps use the USGS file naming convention, in which the first letter of the file name determines the size and scale of the file:

Letter Scale Width Height Comment
R 1:20,000 7.5 minutes 7.5 minutes  
O 1:24,000 7.5 minutes 7.5 minutes  
P 1:24,000 7.5 minutes 7.5 minutes Orthophoto
L 1:25,000 7.5 minutes 7.5 minutes  
J 1:30,000 7.5 minutes 7.5 minutes  
K 1:25,000 15 minutes 7.5 minutes  
I 1:63,360 20,22.5,30,36
15 minutes Alaska only
F 1:100,000 1 degree 0.5 degree  
C 1:250,000 2 degrees 1 degree  

The remainder of the file name includes the encoded values of
latitude, longitude, and relative location of the map image.

Note: All NextGen 7.5 x 7.5 minute USGS maps are distributed as O files

For a more detailed description of quad name standards, see: