From the weekend camera buff to the sophisticated GIS user, 'geotagging' photos with location coordinates has become a popular application of GPS technology. Geotagging, which adds coordinates to a digital image so that it can be accurately placed on a digital map, has spawned a new market we call photo mapping that has compelled the manufacturers of digital cameras, cell phones and GPS receivers to develop a variety of products designed to make it easier to stamp images with GPS points.

In just the past two years, some of the biggest names in cameras - Ricoh, Nikon and Canon - have released models that either have GPS built into the camera body or are designed for direct inputs from an external GPS device. Never wanting to turn their backs on a potential new app, cell phone developers have gotten in on the photo mapping action by integrating cameras and GPS chips inside the phones for automatic geotagging of pictures. And GPS equipment developers like Trimble are approaching the market from the opposite direction by adding cameras  to their newest receivers. GPS digital cameras are popping up everywhere.

At GeoSpatial Experts, we introduced GPS-Photo Link in 2001 as the first software developed specifically for mapping photos. At the time, our software was geared almost exclusively toward professionals who needed to document their photos in a GIS. Over the past few years, however, the photo mapping market has expanded dramatically as camera, GPS and Web-based mapping technologies have evolved and become increasingly intertwined.

Today, we see three distinct groups of end users comprising the market for photo mapping technology: GIS professionals, non-GIS business professionals and recreational photographers. The application needs of these groups are so different that we ultimately created two versions of GPS-Photo Link to serve the GIS and non-GIS professionals.

The purpose of this article is to differentiate these three user groups, and match their needs with the latest GPS digital camera offerings. Ideally, this information will help readers select the photo mapping hardware that best fits their budget and meets the needs of their applications.

GIS Professionals
As the name implies, GIS professionals use GIS or high-end digital mapping software in the course of their daily business. For them, accuracy is critical, sometimes in the sub-meter range. Photo locations must be mapped accurately so they align with all of the other layers of geographic information in their mapping system. The software adds a photo thumbnail or icon on the map to denote where the photo was taken.

In terms of software needs, users in this group rely on photo mapping to record the locations and conditions of features in their GIS. Not surprisingly, they demand the most robust capabilities from commercial photo mapping software. GIS users typically need to convert photo location coordinates into their desired datum and projection, and in many cases they need to record camera metadata that details the direction of the photo as well as the field of view angle. And ultimately, they want to generate reports of their photo mapped feature inventories in a variety of GIS-compatible formats.

Photo mappers in this group are most commonly individuals and organizations who rely on geospatial technology to manage facilities and infrastructure. They use geotagged pictures to create a visual record of where their assets are and what condition they're in at a given point in time. Oil and gas companies, pipeline operators, engineers, environmental consultants, public works departments, the military, utilities, disaster relief workers and government agencies of every kind fall into this category.

Camera Options - Because of the vital role their cameras play in data collection, GIS professionals typically want a rugged camera body with a built-in GPS so they don't have to deal with cables and can use it under adverse field conditions. These users can benefit from a compass linked either to their camera or GPS to record the direction the camera was pointing when the photo was taken. If they need extremely high accuracy, GIS pros also need Wi-Fi or Bluetooth connectivity for differential correction via a base station GPS receiver. (Differential correction uses GPS coordinates from a second GPS receiver to correct, or improve the accuracy, of points collected by the first receiver.)They also look for high-end optics, including the option for interchangeable lenses usually found in a digital single-lens reflex (DSLR) camera, which will produce good image quality.

The best camera choices for this group include the following.

Ricoh 500SE - This 8-mega-pixel camera is the only one designed as a GIS data collection device. Offering superior optics and add-on lenses, the Ricoh comes with integrated GPS and a virtual keypad, which allows users to enter attribute descriptions that are linked permanently to each photo along with the location coordinates. An optional compass attaches to the camera body and provides direction data. If the inherent 3- to 5-meter GPS accuracy isn't sufficient, the Ricoh has Bluetooth and Wi-Fi connectivity making it possible to add a second GPS device for sub-meter differential correction. It's ruggedized and water-resistant. With the compass, users can expect to spend $1400 for the Ricoh 500 SE.

Nikon DSLR Cameras - For GIS users who need to take the sharpest photos possible, Nikon offers two GPS options for its higher-end cameras. For the D5000 and up, Nikons have ports for a wired connection to a handheld GPS receiver, allowing the camera to integrate the location coordinates into the metadata field for each photo. And for photographers who don't like wires connecting two pieces of equipment, Nikon offers the GP-1 GPS receiver that mounts right on the hot shoe of the high-end models (D3, D2xs, D2x, D700, D300, D200, D90, and D5000). Although the Nikons aren't ruggedized like the Ricoh, the $239 GP-1 puts the best camera optics in the world into the hands of photo mapping users.

Canon - Owners of higher-end Canon EOS DSLR models, such as the 1D Mark III, will be pleased to know that Canon has released a wireless transmitter device (WFT-E2) to link the camera with an external GPS receiver. Canon makes terrific cameras and if you already own one, this is a cost-effective option worth considering if the GPS receiver is compatible with your particular camera.

Trimble Juno SC Handheld - Trimble's Juno series of products are best described as handheld computers designed specifically for serious GIS data collection. With built-in GPS, the Junos achieve two- to three-meter accuracy but can be wirelessly linked to a second GPS for differential correction. The SB and SC models include an integrated 3-megapixel pinhole camera. Its photos are automatically geotagged and saved as attributes along with other feature data keyed in by the user. Capable of running ESRI ArcPAD software, the Juno SC costs $749 without data collection software.

Non-GIS Business Professionals
This group uses photography for the same purpose as the GIS users - to inventory the locations and conditions of items and assets - but they usually don't have the same stringent requirements for absolute accuracy. More interested in relative accuracy, they may utilize a simple desktop mapping package as part of their daily operations, but they are just as likely to use Google Earth or a Web page map to display the locations of their GPS photos.

This group is the most rapidly growing sector of photo-mapping users because it potentially includes any individual who can benefit from having a location-stamped photograph-record without a full-scale GIS. Local government agencies are increasingly swelling the ranks of this group as they look for simple and inexpensive ways to inventory infrastructure without the use of their full-blown GIS, usually in support of maintenance activities but sometimes to have a record of asset conditions as a part of emergency preparedness. Police officers, insurance claims adjusters, inspectors and zoning officials are among the most recent to join this group.

Camera Options - Except in rare instances where extremely high image quality is a necessity - such as in crime-scene mapping - the non-GIS business professionals typically have their applications and budgets satisfied by mid-grade camera equipment. Ruggedized camera bodies and interchangeable lenses are less important to these users, and their accuracy requirements fall in the three- to five-meter range. Their best camera options include the following.

Nikon CoolPix P6000 - For under $500, this top-of-the line offering from the Nikon series of CoolPix point-and-shoot cameras is an incredible photo mapping value. It takes 13-megapixel photos and boasts built-in GPS chips for automatic geotagging of each photo. While its optics don't match those of the more pricey DSLRs, this Nikon GPS solution has some zoom and pan capabilities, and it literally fits in your pocket.

Samsung CL65 (ST1000) - Just released in August, 2009, the newest Samsung has a built-in GPS and boasts  Bluetooth and Wi-Fi connectivity. It includes a 3.5-inch touch screen, 12.2 megapixels, and 5x optical zoom. This Samsung GPS camera is expected to cost around $600.

Any Camera/Any GPS - It's easy to forget that before cameras had integrated GPS, the only option was to rely on commercial photo mapping software to merge digital photos and coordinates for you. Given the fact that $100 digital cameras and similarly priced handheld GPS receivers are plentiful, this is still an inexpensive option for someone who doesn't mind carrying two pieces of equipment. All that's required is for the user to snap a digital photo of the GPS screen to synchronize the two devices. With the GPS set to collect continuous points, any robust photo mapping software will correlate the images and coordinates after the fact so the photos can be placed on a map. Many of our long-time GPS-Photo Link customers rely on this configuration because it's so simple and inexpensive. For an investment of $200, this GPS photography solution is hard to beat.

Camera Phones - Several cell phones now have built-in cameras and GPS chips that automatically geotag the photos. Some of these include the iPhone, Blackberry, Samsung Memoir and many new Nokia models. These devices are strictly for use in applications that don't require high-quality photographic images, but they are sufficient if no other camera is available. Buyers should keep in mind that photo quality in a cell phone camera is difficult to judge by any specifications listed on the box. With this in mind, buyers should view sample photos before investing in a cell phone as a photo mapping device. They should also realize the device does not necessarily geotag photos just because it has a camera and GPS. Look for 'geotagging' among its listed capabilities before buying.

Garmin Oregon 550t - In Summer 2009, Garmin released the Oregon 550t, a high-end recreational GPS receiver with built-in digital camera and geotagging capability. The new model is based on the ruggedized Garmin Oregon 400 series, which comes loaded with maps in an iPhone-like body complete with touch screen functionality. Priced at $540, the integrated 3.2-megapixel camera with 4x digital zoom, may soon find itself used by both business and recreational users.

Ricoh 500SE - Mentioned as a top selection for the GIS professionals, the Ricoh GPS camera is a superior option for business users as well. Even though these users may not display their photos in a GIS, the Ricoh data attribute collection capability and compass option are equally beneficial in non-GIS applications. The camera direction and attributes can be listed in reports and noted in Google Earth displays.

Recreational Photographers
For most recreational photographers, the primary goal of photomapping is to post vacation pictures on Google Earth or some other Web-based map to remember where they were taken and share them with friends. These users typically select their hardware based on budget, desired photo quality= and existing camera equipment.

Serious weekend photographers who already own Nikon or Canon SLRs should probably consider buying one of the GPS attachments or GPS-enabling devices described earlier.

People looking to buy a new camera with geotagging functionality should look at the Nikon P6000.

For the rest of us who like to snap photos of our vacations and family events but have to live on a budget, there are several options. Consider buying a camera phone with geotagging capability the next time you upgrade your mobile phone if photo quality doesn't matter that much to you. Otherwise, don't forget the Any Camera/Any GPS option that simply requires a digital camera and a handheld GPS receiver. You'll need software to merge the photos and location points with this configuration, but there are options for that too.

If you simply want to post your photos on a basic digital map and location accuracy is not a major concern for you, free Web-based services such as EveryTrail, Mountain Bike Guru and others will merge the images and coordinates from your Any Camera/Any GPS equipment. And if you have an integrated system that automatically geotags your photos, consider posting them to an online map using Flickr or Picasa.  Note that the CoolPix P6000 comes with its own recreation-grade mapping software.

Looking Ahead
At about $10 a set, GPS chips are inexpensive so we expect to see more GPS cameras like the Nikon CoolPix entering the market with integrated geotagging. More products may push prices lower on those units. For higher-end DSLR cameras, we expect more integrated products like the Ricoh 500SE and add-on GPS receivers like Nikon GP-1. We hope that more manufacturers will understand the value that a compass brings to business-grade photo mapping and introduce more options there. In the meantime, third-party developers are introducing add-on products for various camera models. We've read mixed reviews on them, so do your research before buying.