WorldView-3 to replace GeoEye-2 on Launch Priority

After acquisition of GeoEye, DigitalGlobe’s constellation has expanded to five satellites: WorldView-1, WorldView-2, QuickBird, GeoEye-1 and Ikonos. Out of these five satellite GeoEye-1 and Ikonos are contribution of GeoEye. Each of this satellite has a ‘first’ attached to their name.

Such as :

• Ikonos launched in 1999 was the first commercial  satellite to have 1m resolution
• QuickBird launched in 2002 was the first commercial  satellite to have <1m resolution
• WorldView-1 launched in 2007 was the first commercial satellite to have 50 cm resolution.
• GeoEye-1 launched in 2008 was the first commercial satellite sensor to be able to acquire panchromatic data at 41 cm resolution
• WorldView-2 was the first sub-meter satellite sensor to have 8 multispectral bands to aid in better feature classification.

As you can see each of these satellites has been ahead of its time at the time of its launch. None of these satellites is run-of-the-mill. The same story is likely to continue with WorldView-3 and GeoEye-2. Before the merger of these companies these two satellites were already on construction deck and were half-built. After the merger DigitalGlobe faced the dilemma of doing away with one of them to balance the industry demand and operating cost of these costly satellites. Below are some salient features of these two satellites:

GeoEye-2:

Spatial Resolution	Panchromatc: 0.34 meter Multispectral: 1.36 meter(4-band)
Positional Accuracy	Specification: 5 meter CE90 Expected: 3-4 meter CE90
Collection Capacity	600,000 sqkm Km/day
Swath Width	14.5 km
Dynamic Range	11 bit per pixel
Orbital Altitude	681 km
Nodal Crossing	10.30 am

 

WorldView-3

Panchromatic	Panchromatic: 450 – 800 nm
Multispectral (8 Bands)	8-bands
SWIR Bands (8 Bands)	8-bands
CAVIS* Bands(12 Bands) *Clouds, Aerosol, Vapor, Ice, Snow	12 bands

 

Below are WorldView-3′s non-spectral specifications.

Orbit	Altitude: 617 km
Life	Spec Mission Life: 7.25 years
Sensor Resolution (or GSD, Ground Sample Distance; off-nadir is geometric mean)	Pan Nadir: 0.31 m(20° Off-Nadir: 0.34 m) Multispectral Nadir: 1.24 m(20° Off-Nadir: 1.38 m) SWIR Nadir: 3.70 m(20° Off-Nadir: 4.10 m) CAVIS Nadir: 30.00 m
Dynamic Range	11-bits per pixel Pan and MS 14-bits per pixel SWIR
Swath Width	At nadir: 13.1 km
Geolocation Accuracy(CE90)	Predicted <3.5 m CE90 without ground control
Capacity	680,000 km2 per day

 

Looking at the vast difference in specifications of GeoEye-2 and WorldView-3, it does not look that hard a decision on which satellite to launch first.

DigitalGlobe has confirmed its plan to complete construction of  WorldView-3 satellite on its original schedule and be ready for a launch in mid-2014, meeting the terms of its contract with the U.S. government.

The contract calls for completion and launch of Worldview 3, which will offer the most spectral diversity available commercially and be the first to offer multiple short-wave infrared bands that allow for accurate imaging through haze, fog, dust, smoke and other airborne particulates.

On the other hand GeoEye-2 is planned to be preserved for future use in case any of the satellite fails.

You can visit our previous blogpost where we discussed WorldView-3 in detail here