Earth Observation Satellites (EOS)

Q What is the context  ?

A After a disappointing 2021 which saw just one successful launch, ISRO is getting back to business with the EOS-04, an earth observation satellite.

Q What are EOS?

A 

• An EOS or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit.
• It includes spy satellites and similar ones intended for non-military uses such as environmental monitoring, meteorology, cartography, and others.
• The most common type is Earth-imaging satellites that take satellite images, analogous to aerial photographs.
• Some EOS may perform remote sensing without forming pictures, such as in GNSS radio occultation.

Q What is EOS-04 all about?

A 

• The EOS-04 is fourth in a series of earth observation satellites that are being launched under a new generic name.
• It is designed to provide high-quality images for applications such as agriculture, forestry, and plantations, flood mapping, soil moisture, and hydrology.
• It will complement the data from Resourcesat, Cartosat and RISAT-2B series of satellites that are already in orbit.

Q Why such different nomenclature?

A 

• Two years ago, ISRO had moved to a new naming system for its earth observation satellites which till then had been named thematically, according to the purpose they were meant for.
• The Cartosat series of satellites were meant to provide data for land topography and mapping, while the Oceansat satellites were meant for observations overseas.
• Some INSAT-series, Resourcesat series, GISAT, Scatsat, and a few other earth observation satellites were named differently for the specific jobs they were assigned to do, or the different instruments that they.
• All these would now become part of the new EOS series of satellites.

Q What other satellites are being launched?

A 

• Besides EOS-04, two other small satellites —INSPIREsat-1 and INS-2TD — will ride on the heaviest version of the PSLV rocket in the early hours from the Sriharikota launch range.
• The other co-passenger, INS-2TD, is a technology demonstrator for the first India-Bhutan joint satellite that is scheduled to be launched next month.
• The two countries had signed a space agreement last year, and its first outcome would be the launch of Bhutan-Sat, or INS-2B, on a PSLV rocket.

Q How many satellites does India have in space?

A 

• India currently has 53 operational satellites, of which 21 are earth observation ones and another 21 are communication-based.
• EOS-4 launch would be the 54th flight of the PSLV rocket, and the 23rd of its most powerful XL-version that has six strap-on boosters.