Validating Satellite Data and Images

SPECTRAL EVOLUTION provides two ways to validate satellite sensors: calibrating the NIR sensors on a satellite pre-launch using an SR-3500, and the PSR+ 3500 for for ongoing calibration.

The SR-3500 and PSR+ both use three photodiode array detectors to cover the following ranges:

  • 512 element Si array – 350-1000nm
  • 256 InGaAs array – 1000-1900nm
  • 256 InGaAs array – 1900-2500nm

The SR-3500 is well-suited to support radiometric calibration transfer for integrating spheres calibrating satellites to NIST- traceable standards.

For pre-flight calibration, the SR-3500 delivers the following features:

  • Spectral resolution 350—2500nm
  • UV/VIS/NIR full range, fast, one-touch scanning
  • Compact, lightweight and reliable with no moving parts
  • Autoexposure, autoscaling, and auto dark current shutter
  • Easy to set up anywhere
  • Long-term stability
  • DARWin SP Data Acquisition software captures spectra in ASCII format for use with third party software—no pre- processing required

The data from the Landsat sensors is used in research on climate effects, crops and soil research, geographic studies, field spectroscopy, ice and snow research, ocean studies, geological remote sensing, alteration zone mapping, mining exploration, and more.

Post-launch, satellite imagery requires ground truthing calibration that can be ideally handled by the PSR+. Lightweight, compact, and portable, the PSR+ provides the following capabilities: Full UV/VIS/NIR across a 350-2500nm spectral range Spectral resolution of 3nm from 350-1000nm; 8nm@1500nm; 6nm@2100nm Use for standalone data acquisition or with a laptop or Getac personal digital assistant (PDA) with a built-in GPS, autofocus digital camera, e-compass, altimeter, recording for voice notes, and high visibility/daylight display

PSR+ Spectroradiometer

The SR-3500 and PSR+ 3500 both play a role in validating satellite data and imagery for satellites such as the Landsat 8. The launch of Landsat 8 as part of NASA’s Landsat Data Continuity Mission (LDCM) will provide researchers in many remote sensing and mining applications with free access to the latest in images and data collected in specific areas of the VIS/NIR spectrum. In fact, this launch is one of more than forty international satellite launches scheduled for 2013.