You can find answers here to some general questions about satellite imagery and Geoimage.
Frequently Asked Questions
There are different type of resolutions such as spatial, temporal and spectral in regard to Earth observation. In reference to information such as ‘30cm very high resolution imagery’ for example, this refers to the spatial resolution. Spatial resolution is describing what can be represented by one pixel in an image.
For example, a 30cm resolution image means that one pixel in the image represents 30cm x 30cm. To put this in perspective, an average car of 4.2m (420cm) – would equate to 14 pixels on the image. By referring to satellite imagery with these resolution values, this gives a clear indication of objects that can and cannot be detected in an image.
Archive imagery is recovered from historical databases. These are very useful in monitoring use cases or when comparing past images or data sets. Fresh imagery requires tasking the satellites to capture a specific area of interest (AOI) for a recent image. Typically, archive imagery is less expensive as it has already been captured whereas tasking a satellite to capture a specific area will incur additional costs. To understand which option is best for you, contact our Sales Team.
Depending on your AOI (area of interest) and the service you require this can influence the price of a project as different satellites may be used. If you require only archive data or a fresh capture this is also taken into consideration as archive imagery is typically less expensive than a new tasked image.
When you submit the Request a Quote form and fill in the details, our team then provide you with an indicative cost. We can advise on the best solutions to your project needs and then a formal quote is provided when you are happy with the available options. The image below explains the Geoimage process on how to buy satellite imagery.
Aerial imagery is where photographs are taken from a flying object such as an aircraft or drone. Satellite imagery on the other hand are images and data taken from sensors onboard satellites orbiting the Earth. Both forms of imagery have a wide range of applications and use cases. There are some significant differences when considering aerial or satellite imagery.
As aerial imagery is captured closer to the Earth’s surface, weather conditions need to be taken into consideration for data acquisition. The cost of fuel for aircraft surveys is also a factor in determining the flight duration for the area of interest. Satellite imagery does not have these restrictions and can capture large areas in a single pass. As satellites are located in the outer layers of Earth’s atmosphere, images taken require some type of geometric corrections to reflect real world map projections. This processing is done before delivery of the images to clients. However raw images are also able to be supplied if requested.
This depends on the use case as both forms of data provide valuable insights. Optical imagery for example is similar to what we may see with the human eye and so may be easier to digest. However radar imagery can penetrate through cloud and haze cover with the ability to also capture at night. Radar images can also bring up details in a different way than optical imagery. Have a look at some of the comparisons in our blog where we discuss how Synthetic Aperture Radar is captured.
The difference in optical or radar imagery is how the data is acquired. Radar data forms an image as the satellite sensors send and receive reflected radiowaves from surfaces on the Earth. Optical images on the other hand use techniques similar to a camera with a lens. They are both capable of providing great data insights and at Geoimage we can suggest the best type of imagery depending on your project.
To make this understanding simple, let’s start with a little background. Energy is carried by a single photon (which is a type of particle). This energy is reflective of a single photon’s electromagnetic frequency, which is proportional to its wavelength. The wavelengths range across the electromagnetic spectrum and are representative of solar radiation (light) that is reflected off the Earth’s surface.
Spectral bands in satellite imagery refer to the different type of wavelengths that satellite sensors detect. By using different bands, various insights can be highlighted. Different spectral bands are better suited in detecting certain objects. For the satellites that Geoimage has access to, the types of bands that each satellite uses can be found on their corresponding Satellite & Sensors page.
Geoimage are satellite imagery providers. We partner with some of the largest satellite vendors on the globe such as Maxar and Airbus. We can task the satellites for fresh captures and can request archive imagery from large databases. We can deliver raw imagery or ‘clean up’ an image with processing including orthorectification, pan sharpening, etc. We also provide data analysis on imagery including 3D Digital Elevation Models called DEMs, Shortwave Infrared (SWIR) analysis, surface movement monitoring through InSAR and other data applications. With satellite imagery, different perspectives enable projects to gain valuable insights that can be fundamental to the decision-making process.
There are several thousand types of satellites orbiting the Earth since the first ever artificial satellite was launched in 1957 called Sputnik. Some of these include communication satellites, weather satellites and navigational satellites. However imaging satellites (as the name suggests), are used to capture imagery for Earth observation. They are also known as Remote Sensing Satellites.
Geoimage uses these satellites from our partners such as Airbus, Maxar, RESTEC and Pixxel for all imagery requests. Satellites generally operate for a number of years where more advanced satellites are launched in succession. Depending on the technology used they offer capture abilities at different resolutions and spectral bands. Under our Satellites & Sensors page you can view all the satellites we currently use with details on their technical specifications.
Geoimage has been providing clients with satellite imagery solutions for over 30 years. Our experience allows us to provide the best recommendations including processing services custom suited for use which alternatives such as Google Earth and other free imagery providers cannot deliver. Geoimage provides rapid delivery options and greater information to clients so more detailed evaluations of the area can be carried out.
Geoimage’s standard delivery time is 10 working days (after successful capture); however, priority processing can be implemented. A delivery date will be confirmed by the Sales Representative once the order has been placed.
The largest data set Geoimage has handled is our bi-annual NSW 1.5m state-wide mosaic.
Geoimage has appeared on 2 of Australia’s television news programs including 60 Minutes and 7NEWS discussing satellite imagery on various use cases.
Geoimage is Maxar’s only Gold Reseller in the Australasian region.