Medium Resolution Satellite Imagery
Satellite imagery has become a staple in the geospatial community. There are many different satellite imagery providers, each of whom has their own set of sensors. One group of sensors is the medium resolution collectors. But why would you want medium resolution imagery when high resolution (30 centimeter) imagery may be available?
Before we get into why medium resolution imagery may be better for a specific project, it is important to understand what medium resolution means. Resolution is the size of each individual pixel within an image. Some sensors can gather imagery with a resolution of 30 centimeters (each pixel within the image covers 30 centimeters of land), this is considered high resolution. Medium resolution, on the other hand, is imagery with a resolution of two to five meters, meaning that each pixel within that image would cover anywhere between two meters to five meters on the earth. Anything above five meters would be considered low resolution.
Returning to our original question, one of the considerations may be cost. The cost of medium resolution imagery is usually much less than that of high resolution. When a project covers thousands of kilometers of land an organization can end up spending a significant sum to collect and process the imagery. When ordering medium resolution imagery though, each square kilometer collected can cost as little as a dollar. High resolution imagery on the other hand can cost upwards of $20 per square kilometer as a base price.
Secondly, if a project is very large and it isn’t necessary to see an extremely high level of detail it may be smarter to consider medium resolution because that level of detail may be all that is needed to get the job done. When using satellite imagery to monitor crop health over a large region or to map a national forest, 30 cm imagery may be overkill. Agricultural or forestry workers don’t necessarily need to see each individual plant within their designated area, but they do need to see if a large corner of a field has died because of a recent drought. When looking at the ‘big picture’ sometimes the small details can get in the way, it is for this reason that medium resolution may be a more cost effective option.
Be it for cost or due to a large project size, the old saying stands true: “less is sometimes more.” When getting ready to start your next geospatial project, you have many factors to consider just to get going, why bog yourself down with more? Maybe you aren’t sure what is the best resolution for you. Whatever the case may be, eMap International is here to help you figure it out and get you headed in the right direction. Give us a call or drop us an email to start discussing what we can do for you.