Question: Eartha is located within the headquarters of a producer of personal satellite tracking, messaging, and navigation technology, whose main product is what?

Context articles: Jeremy Wood
Hi Target UAV
Satellite navigation
Wildlife radio telemetry
DeLorme
Main product
Zemanta
PSWinCom
Blue Sky Network
Eartha

Jeremy Wood is a UK based GPS artist.
 Over the past ten years, Wood has pioneered the act of drawing and mapping with satellite navigation technology and video by treating himself as a geodesic pencil.
 His everyday journeys are compiled to map his whereabouts and present a personal cartography that reveals a unique and detailed interaction with space and time.
 His work is an expression of the poetry and politics of space and reflects upon how we treat our travels and interact with location.
 He has received laudations ranging from Wired Magazine to cutting-edge academic theory, including a November 2009 feature in the peer-reviewed Cartographic Journal.
The Hi Target UAV is a Chinese unmanned aerial vehicle developed by Guangzhou Zhong-Hai-Da Satellite Navigation Technology Co., Ltd. (Hi Target, 广州中海达卫星导航技术股份有限公司).
 Originally a provider of satellite navigation system and other associate systems such as software for various platforms, including UAVs, Hi Target has begun to produce UAVs for survey missions by jointly develop such UAVs with other Chinese UAV manufacturers.
A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning.
 It allows small electronic receivers to determine their location (longitude, latitude, and altitude/elevation) to high precision (within a few metres) using time signals transmitted along a line of sight by radio from satellites.
 The system can be used for providing position, navigation or for tracking the position of something fitted with a receiver (satellite tracking).
 The signals also allow the electronic receiver to calculate the current local time to high precision, which allows time synchronisation.
 Satnav systems operate independently of any telephonic or internet reception, though these technologies can enhance the usefulness of the positioning information generated.
Since its inception in the 1960s, wildlife radio telemetry has become a valuable tool to track the movement and behavior of animals.
 This technique uses the transmission of radio signals to locate a transmitter attached to the animal of interest.
 It is often used to obtain location data on the animal's preferred habitat, home range, and to understand population dynamics.
 The different types of radio telemetry techniques include very high frequency (VHF) transmitters, global positioning system (GPS) tracking, and satellite tracking.
 Recent advances in technology have improved radio telemetry techniques by increasing the efficacy of data collection.
 However, studies involving radio telemetry should be reviewed in order to determine if newer techniques, such as collars that transmit the location to the operator via satellites, are actually required to accomplish the goals of the study.
DeLorme is a producer of personal satellite tracking, messaging, and navigation technology.
 The company’s main product, "inReach", integrates GPS and satellite technologies.
 "inReach" provides the ability to send and receive text messages anywhere in the world (including when beyond cell phone range) by using the Iridium satellite constellation.
 By pairing with a smart phone, navigation is possible with access to free downloadable topographic maps and NOAA charts.
 On February 11, 2016, the company announced in 2016 that it had been purchased by Garmin, a multinational producer of GPS products and services.
A main product is a joint output that generates a significant portion of the net realizable value (NRV) within a joint production process.
 The classification of a product resulting from a joint production process as either a main product or a by-product has relevance in the context of cost management because costs are only allocated to main products, not to by-products.
Zemanta is a private company whose main product is an enterprise platform for content marketing.
 It's Zemanta One platform utilizes real-time bidding (RTB) to help brands, trade desks and digital agencies promote marketing content to global audiences.
 Zemanta has headquarters in New York City and Ljubljana, Slovenia.
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 The company has been bought by Outbrain in July 2017, but continues to operate under its own brand.
PSWinCom is a technology company in Norway.
 It delivers services and software for sending and receiving global SMS (Short message service) and MMS messages.
 The main product is SMS Gateway, used for integrating mobile messaging in software and IT systems.
Blue Sky Network is a global satellite technology company headquartered in San Diego, California.
 Founded in 2001, Blue Sky Network offers satellite tracking solutions to support fleet managers and operators monitoring land, marine, and aviation assets.
 Powered by Iridium’s satellite network, Blue Sky Network serves customers in all seven continents of the world.
 As an authorized Tier 1 Iridium Communications partner since 2002.
Eartha is the world's largest rotating and revolving globe, located within the headquarters of the DeLorme mapping corporation in Yarmouth, Maine.
 The globe weighs approximately 5,600 pounds (2,500 kg), and has a diameter of over 41 feet (12.5 m).