FAQ - Geospatial Marketplace | Harris MapMart

MapMart FAQs

Frequently Asked Questions

1) What is MapMart?

MapMart is an online resource for the location and acquisition of quality digital data. MapMart sells numerous digital data products including Digital Elevation Models, Digital Vector Maps, Topographical Maps, Aerial Photography and Satellite Imagery as well numerous GIS software systems. MapMart’s unique online interface allows users to zoom-in to an area of interest, determine digital data availability and oftensee a preview of the data online prior to purchase. Some data is available for immediate download in a customer defined coordinate system and software format.Otherwise most data are available for download within a matter of days or hours.

2) What types of products are available from MapMart?

MapMart offers a wide variety of topographic, elevation, and satellite imagery data from the top creators in the industry. Click here to see a list of our current partners. MapMart also offers a variety of USGS products, including digital topographic maps, vector line work, LandSat and derived satellite Imagery, and the latest NED data.

MapMart also offers several widely used Software Packages including Esri, MapInfo, LizardTech and MET software products.

MapMart offers one of the most extensive online networks for locating historical Aerial Photography, from the late 1920's up to the current month. You are able to view a listing of all years and scales of photography available for your particular area before requesting any information from our specialists.

3) Why should I buy mapping products from MapMart?

MapMart allows you to buy digital map data for the area you need in the format and projection you require. No conversion process is necessary on your part. Buying from MapMart or MapMartMobile is convenient, efficient and cost effective. Our unique user interface lets you see the availability of a product, select the product and data format you prefer, and determine your cost before placing the order. We also offer a variety of services from our technical support staff to get you the answers you need right away.

4) What is MapMart Mobile and how does it work?

MapMart Mobile is a free app for your mobile device that allows you to search through the most extensive databases of imagery available very quickly and easily. Defining the area of interest, browsing the available options and submitting your contact details for more information takes only minutes. Click here for more information.

5) Doesn't the U.S. Geological Survey have a similar web site?

The USGS web sites are very informative and technically oriented. However, ordering products can be difficult. The USGS sites do not allow for a choice of data formats. MapMart was designed to allow users to quickly and easily order the product they need. If the desired product is not available from the USGS, MapMart has the capability to create the product necessary to fulfill your mapping needs.

MapMart has a business partnership with the USGS as well that allows us to access the raw data faster than most. We are able to deliver in a few days where the USGS may take a few weeks.

6) What if the product or format I need is not available?

Call us at 1-303-759-5050x2. We can provide the following services:

  • Data and Imagery Hosting
  • Imagery acquisition: Both Historical and Current
  • Photogrammetry services
  • Ortho-photography and image processing
  • Digital conversions and Custom Vector creation
  • Large-scale color scanning and plotting
  • Geologic Mapping
  • Environmental Interpretation
  • CAD and GIS solutions
  • Traditional and GPS survey services

7) What are the prices of the various mapping products?

For your specific order price, zoom-in to your area of interest, define the area you need and select your desired products. You will be able to customize your products and, at your request, MapMart will calculate preliminary pricing based on your selections.

8) How long will my order take to process?

Some of our data are available for immediate download including most USGS-derived data sets and much of the current aerial imagery. Most other digital products will be completed and shipped between two to three business days. Rush services are available at a cost of 50% of your data charge. With the rush services option, we process your order as quickly as we possibly can.

9) What if I want to return the product I ordered?

MapMart will accept most product returns less a 25% restocking fee within 30 days. You must notify MapMart prior to returning the product. MapMart will not accept returns of Custom data products, like Custom Scans, Custom Digitizing, Custom Prints, etc. MapMart will also not accept returns of USGS paper map products. See Terms and Conditions for full details.


A common USGS Scale. Also known as 1:100,000 or 1 inch on the map equals 100,000 inches on the earth (1 inch = 8333.33 feet = 157828 miles).

A common USGS Scale. Also known as 1:24,000 or 1 inch on the map equals 24,000 inches or 2,000 feet on the earth. This is usually considered a large scale (1/24,000) (1 inch = 2000 feet = 0.37878 miles).

A common USGS Scale. Also known as 1:250,000 or 1 inch on the map equals 250,000 inches on the earth. This is usually considered a small scale (1/250,000) (1 inch = 3.945707).

3 Arc Second
Three seconds of latitude or longitude. Approximately 90 meter resolution in North America (~60 meters in Alaska) and varies based on latitude. A common DEM spacing

7.5 Minute (7.5')
A common USGS area of extent used with 1:24,000 topographic maps (or quads). Implies 7.5 minutes of latitude by 7.5 minutes of longitude. Approximately 7 x 9 miles.

The degree in which a measured value in correct.

Describes map information represented by a point, line, or area. For example, an attribute for an area might identify a lake or swamp; an attribute for a line might identify a road, railroad, stream, or shoreline.

Information found around the edges of a topographic map. This information includes: Quadrangle Name, Year of Publication, Corner Coordinates, Projection, etc.

Refers to DRGs that have no edge information. Collarless DRGs are ideal for mosaicking multiple DRGs together. Thus allowing one to create a seamless digital topographic map of a very large area.

Color Infrared Photo (CIR)
CIR film is manufactured in a way that makes it more sensitive to the near-infrared portion of the spectrum. On a CIR photo, infrared energy is represented by tones of red. It is most commonly used for vegetation studies.


Contact Print
Describes a photograph produced directly from a negative of the same size.

Control Point
Features of known ground location that can be accurately located on imagery.

Line of equal elevation.

Digital Elevation Model. A digital file containing equally spaced elevation points represented with an X (east-west value), a Y (north-south value) and a Z (elevation value).

Digital Line Graph. A vector format used widely by the USGS in the 1980s and 1990s. Since replaced by SDTS.

Digital Orthophoto Quad. A USGS Aerial Photo product of One-Meter resolution. 7.5’ Area, created from NAPP Photography.

Digital Orthophoto Quarter Quad. A USGS Aerial Photo product of One-Meter resolution. 3.75’ Area, Created from NAPP Photography.

Digital Raster Graphic. A USGS product. A scanned USGS topographic map.

Defines the size and shape of the earth. NAD 27, 83 and WGS 84 are the most common.

Decimal Degrees
Latitude/Longitude or Geographic coordinates. The degree fraction is shown as a decimal instead of minutes and seconds (eg., 39.125,-104.375)

Degrees Minutes Seconds
Latitude/Longitude or Geographic Coordinates. The earth is divided into 360 degrees(°), where a degree equals 60 minutes(') and 60 seconds(") equals a minute (eg., 39° 7' 30", -104 22' 30")

A transparent positive on plastic-based film used for creating topographic maps.

Digital Print
A print generated off a digital file rather than a photo print from a traditional negative.

Earth Resources Observation Systems Data Center. EDC is a national archive, production, distribution, and research facility for remotely sensed data and other geographic information. Located in Sioux Falls, SD.

A World DEM dataset with a resolution of 2 minutes. Includes Ocean Depths, released in 2001 by NOAA.

A World DEM dataset with a resolution of 5 minutes. Includes Ocean Depths, released in 1988 by NOAA.

Federal Information Processing Standard. This is a standardized code used by the USGS and the Federal Government.

Data Format - A file type that can be read by a particular software program. Eg., ArcView Software reads .shp or Shape file format.

One meter black and white Aerial Photography of the United States. Created from DOQQs. 1990 - 2000

Geographic Information System. Software program used to analyize spatial data in a variety of ways.

A World DEM dataset with a resolution of 30 Seconds or approximately 900 meters. Does not include Ocean Depths, completed in late 1996. Developed over a three year period through a collaborative effort led by the U.S. Geological Survey.

The scientific study and mapping of the earth's topography. Sometimes refers to the contour vector layer.

LandSat 5
Satellite launched in March, 1984 as a NASA/USGS initiative. Carries the 30-Meter Thematic Mapper (TM) sensor. Remains in operation today.

LandSat 7
Satellite launched in April, 1999 as a NASA/NOAA/USGS initiative. Carries a new sensor called the Enhanced Thematic Mapper Plus (ETM+). Contains a 15-Meter Panchromatic Band. Remains in limited operation today.

Large Scale
The word 'Large' refers to the fraction 'Units on map / Units on earth' (eg., 1/24,000). Implies a map or photo showing a high amount of detail but a small area.

Angular distance, in degrees of a point north or south of the Equator. Also thought of as an E-W line parallel to the equator denoting a North or South position.

Angular distance, in degrees of a point east or west of Greenwich, England. Also thought of as a N-S line or meridian denoting an East or West position.

Merging two or more spatial data files into one seamless file.

North American Datum of 1927. NAD27 is defined with an initial point at Meads Ranch, Kansas, and by the parameters of the Clarke 1866 ellipsoid. The location of features on most USGS topographic maps, including the definition of 7.5-minute quadrangle corners are referenced to the NAD27.

North American Datum of 1983. NAD83 is an Earth-centered datum and uses the Geodetic Reference System 1980 (GRS 80) ellipsoid, unlike NAD27, which is based on an initial point (Meades Ranch, Kansas). Using recent measurements with modern geodetic, gravimetric, astrodynamic, and astronomic instruments, the GRS 80 ellipsoid has been defined as a best fit to the worldwide geoid. Because the NAD83 surface deviates from the NAD27 surface, the position of a point based on the two reference datums will be different.

National Agriculture Imagery Program. Started in 2002 by the USDA. Purpose is to quickly create digital aerial photography at one and two meter resolutions. An emphasis is given to areas containing agricultural land.

National Aerial Photography Program. NAPP was established to coordinate the collection of aerial photography covering the 48 contiguous States and Hawaii every five years. The NAPP goals are to ensure that photography with uniform scale, quality, and cloud-free coverage be made available to meet the requirements of several Federal and State agencies. The program was initiated in 1980 as the National High Altitude Photography (NHAP) program. In 1987, the program was renamed to NAPP when the flying height for the program changed from 40,000 feet to 20,000 feet. NAPP photography is available in black and white, and in most cases, color-infrared. The program is administered by the U.S. Geological Survey's National Mapping Division. NAPP imagery is used by the USGS for photo revision and land use land cover characterization work on the standard series maps at 1:24,000; 1:100,000 and 1:250,000 scales.

Natural Color Photos
Aerial photographs produced in natural color are less common and more expensive but can be more useful because the human eye can discriminate between color variations better than shades of gray.

Neatlines separate the body of a map from the map margin. On quadrangle maps, the neatlines are often the latitude and longitude that delimit the quadrangle.

Oblique Photos
These photos are taken with the camera axis at an angle other than 90° to the ground. The image can be a high oblique, which includes a horizon, or a low oblique, which does not.

A reconstructed aerial photo in which all X,Y distortion has been removed.

Orthophoto Mosaic
A mosaic constructed from orthophotos. The image is seamless because the scale variations and distortions have been removed.

Planimetric Map
Similar to a topographic map in that locations and features are identified. The identifying characteristic is that planimetric maps lack elevation contours or relief.

Public Land Survey System. The U.S. Public Land Survey System is the most widespread land ownership system in the United States. Land is subdivided by a rectangular system of surveys established and regulated by the Bureau of Land Management. The standard format for subdivision is based on townships measuring 6 miles (480 chains) on a side. Townships are further subdivided into 36 numbered sections of 1 square mile (640 acres) each. PLSS descriptions are made as Township, Range, Section values (for example; the S half of the NE corner of Sec 15, T32N, R7W).

Photo Index
A grid map to reference individual aerial photos.

Four-sided area, bounded by parallels of latitude and meridians of longitude. Usually refers to a topographic map and commonly called a quad.

A spatial image where the data is expressed as a matrix of cells or pixels, with spatial position implicit in the ordering of the pixels. This data is particularly suitable for certain types of spatial operations (e.g., overlays or area calculations). Unlike vector data, there are no implicit topological relationships.

The process of removing X and Z distortions from a digital aerial photo.

A measure of the amount of detail that can be seen in an image; the earth size of a pixel. For example a 2 foot pixel resolution means that each pixel of the imagery covers a 2 foot x 2 foot area on the ground, 1 foot resolution covers 1 foot x 1 foot area on the ground. The smaller the resolution, the more detail a person can see.

Spatial Data Transfer Standard. The SDTS was approved in July 1992 as Federal Information Processing Standard (FIPS) 173. This Standard is actually a spatial data format used widely by the USGS.

90 Meter global DEM data obtained from the Shuttle Radar Topography Mission. Data obtained in February of 2000.

A spacecraft that orbits another body, such as a planet or the sun.

Relationship existing between a distance on a map and the corresponding distance on the Earth.

Data where the boundaries are defined by the user. Traditionally boundaries have been pre-defined by 7.5', 30' x 60' or 2° x 1° areas of Latitude and Longitude.

Small Scale
The word 'Small' refers to the fraction 'Units on map / Units on earth' (1/250,000). Implies a map or photo covering a large area but showing a small amount of detail.

State Plane
The State Plane projection is unique to the United States. The values are in English Units (feet, yards, miles etc.) and the zones used within the projection are smaller and more specific to each state.

Stereo Pair
Two adjacent, overlapping aerial photos that when viewed together through a stereoscope produce a 3D image.

Thematic Mapper - A Landsat multispectral scanner designed to acquire data to categorize the Earth's surface. Particular emphasis was placed on agricultural applications and identification of land use. The scanner continuously scans the surface of the Earth, simultaneously acquiring data in seven spectral channels. Overlaying two or more bands produces a false color image. The ground resolution of the six visible and shortwave bands of the Thematic Mapper is 30 meters, and the resolution of the thermal infrared band is 120 meters. Thematic mappers were flown on Landsat 4 and 5.

Topographic Map
Maps that present the horizontal and vertical positions of the features represented; distinguished from a planimetric map by the addition of relief - elevation element.

United States Geological Survey. Established in March of 1879, the Geological Survey's primary responsibilities are: investigating and assessing the Nation's land, water, energy, and mineral resources; conducting research on global change; investigating natural hazards such as earthquakes, volcanos, landslides, floods, droughts; and conducting the National Mapping Program. To attain these objectives, the Geological Survey prepares maps and digital and cartographic data; collects and interprets data on energy and mineral resources; conducts nationwide assessments of the quality, quantity, and use of the Nation's water resource; performs fundamental and applied research in the sciences and techniques involved; and publishes and disseminates the results of its investigations in thousands of new maps and reports each year.

Universal Transverse Mercator projection. This is a very common projection and is used by the USGS. It is based on 6 degree zones of longitude surrounding the earth and the units are in millions of meters.

Vector Map (VMap) Level 0 is an updated and improved version of the National Imagery and Mapping Agency's (NIMA) Digital Chart of the World (DCW®). The VMap Level 0 database provides worldwide coverage of vector-based geospatial data. The primary source for VMAP0 is the 1:1,000,000 scale Operational Navigation Chart (ONC) series co-produced by the military mapping authorities of Australia, Canada, United Kingdom, and the United States. VMap Level 0 includes major road and rail networks, hydrologic drainage systems, utility networks (cross-country pipelines and communication lines), major airports, elevation contours, coastlines, international boundaries and populated places.

Refers to a format where all spatial data is stored as points, lines, and areas rather than as an image or continuous tone picture (raster). Vector data often have location and attribute information associated with them.

Vertical Photos (required for stereo)
These are the most common type of aerial photographs. They are produced with the camera axis aimed vertically, perpendicular to the ground.