1. NASA Earth Science Applied Sciences Program
Applications to Decision Making: Thematic Areas
Agricultural
Efficiency
Climate
Disaster Management
Ecological Forecasting
Water
Resources
Public Health
Weather

2. Applied Remote Sensing Training Program (ARSET)
(part of NASA Applied Sciences)
GOAL:
Increase utilization of NASA observational and model data for decision-support
Online and hands-on courses:
Who: policy makers, environmental
managers, modelers and other professionals
in the public and private sectors.
Where: U.S and internationally
When: throughout the year. Check websites.
Do NOT require prior remote- sensing
background.
Presentations and hands-on guided
computer exercises on how to access,
interpret and use NASA satellite images for
decision-support.
NASA Training for California Air Resources Board, Sacramento

3. Applied Remote Sensing Training Program (ARSET)
Health (Air Quality)
2008 – present
26 Trainings
+700 end-users
Analysis of dust, fires and urban air pollution.
Long range transport of pollutants
Satellite and regional air quality model inter-comparisons.
Support for air quality forecasting
and exceptional event analysis
Water Resources and Flood Monitoring
April 2011 – present
6 Trainings
+300 end-users
Flood/Drought monitoring
Severe weather and
precipitation
Watershed management
Climate impacts on water resources
Snow/ice monitoring
Evapotranspiration (ET), ground water, soil moisture, and runoff.
Nitrogen Dioxide over China
Satellite derived precipitation
Inundation mapping
Land Use/Change and Ecology
Beginning in 2014
Webinars and in-person courses
Topics to be informed by ongoing end-user needs assessment
GIS applications
Land use/change and vegetation indices
Fire products
Land Cover
LAND COVER
Smoke

4. Assumes no prior knowledge of RS Webinar course generally required
Gradual Learning Approach
Basic Courses
Webinars
Hands-on
Assumes no prior knowledge of RS
Advanced Courses
Hands-on
Webinar course generally required
Focused on a specific application/problem: for example dust or smoke monitoring in a specific country or region
Learning how to use NASA data for applications and/or decision-support is a multi step process. Most end-users have a technical background, but not a remote sensing background, we therefore require a basic online or in person course, that teaches remote sensing basics, before students can move into hands on and/or advanced courses. We recently also began advanced online courses, based on end-users requests. In the next slide, I will talk more about the online courses.

5. ARSET: 2009 – 2013 +1000 End-users Reached
Number of participating organizations per country: Air Quality, Water Resources, Flood Monitoring.
ARSET also conducts international trainings. In Asia, supporting NASA campaigns, also supporting SERVIR in Central America. In Canada, trainings have been done in collaboration with the Air and Waste Management Association, so the end-users reached in Canada have been primarily private for-profit sector, also a few ad-hoc trainings have been conducted at international conferences.

6. http://airquality.gsfc.nasa.gov/ Publicly available Upcoming trainings
Modules
Case
Studies
Upcoming trainings
ARSET web page is used to announce courses, and to post trainings materials, and for online course registration. IF you’d like to contribute your materials, please contact the ARSET-AQ team.

7. NOTE: New ARSET website coming soon Sign up to the listserve for new website information and URL, and for program updates

8. Overall program information Ana Prados: aprados@umbc.edu
ARSET Contact Information
Overall program information
Ana Prados:
Interest in future ARSET activities
Pawan Gupta:

9. Fundamentals of Satellite Remote Sensing Instruments and Applications
Introduction to Remote Sensing and Air Quality Applications for the Indian Sub-Continent and Surrounding Regions
ARSET
Applied Remote SEnsing Training
A project of NASA Applied Sciences

10. Outline What you should expect from this course.
Why use remote sensing?
Advantages and Limitations of Remote Sensing
Sensors and Satellites
Satellite Capabilities, Satellite Products and their Application to Remote Sensing

11. What should you expect from this webinar series?
Satellite Measurements
Satellite Products
This course will provide an introduction and overview to satellite measurements, satellite products and how they are related to each other and to air quality applications. It will also provide you with exposure to some of the more easily used web based tools for viewing satellite images and qualitative examination of data.
Air Quality Applications

12. What should you not expect as a result of this webinar series ?
The capability to perform research using satellite remote sensing data.
A complete knowledge of all of the satellite products and web tools which can be used for air quality applications.

13. Some Things We Want to Know About Aerosols and Trace Gasses
Sources and sinks
Concentrations at the ground
Human exposure estimates
Acute exposure
Long term records
Air quality forecasts
These are the practical applications for air quality which come at the end of the chain from remote sensing instrument to product to application.

14. Global Status of PM2.5 Monitoring Networks
Ground sensors give us by far the most accurate measurements of ground level pollutants. The ground sensor networks (not a complete list of all ground stations globally) are indicated by the colored dots on the upper image. The image on the lower right shows population density. You can see that several areas of the globe with significant populations have almost no monitors at all. In addition most of the sensors in India and China are measuring calculating PM 2.5 from PM 10 measurements. One important thing to note is that even in the U.S., the most completely instrumented country in the world, 2400 out of 3100 counties (31% of total population) have no PM monitoring.
Brauer M, Ammann M, Burnett R et al.
GBD 2010 Outdoor Air Pollution Expert Group Submitted –under review

15. Why Use Remote Sensing Data?
Spatial Coverage
Increased spatial coverage is the most important advantage satellite measurements offer compared to ground monitors. The multi-state area shown at the right is one of the most heavily instrumented areas in the world. On the left the green dots show locations for aerosol measurements from a single MODIS overpass. This image give a representation of MODIS 10 x 10 kilometer data. Finer resolution measurements are possible. More will be presented about this during the course.
- Satellite (MODIS) Retrieval Locations
White Areas – No Data
(Most likely due to clouds)
– Ground Monitors

16. MODIS One Day Aerosol Product Coverage
Spatial Coverage
MODIS One Day Aerosol Product Coverage
This is an image of a typical single day global measurement of aerosols made by MODIS. We will explain the gaps in the image in future sessions.

17. Satellite Products for Air Quality Applications
Particulate Pollution (dust, haze, smoke)
- Qualitative: Visual imagery
- Quantitative*: Atmospheric Column Products
Fire Products: Fire locations or ‘hot spots’
Fire radiative power
Trace Gases
- Quantitative*: Column Products
- Vertical profiles: mostly mid-troposphere
- Some layer products
These are the remote sensing products which can be used in remote sensing applications.

18. Some kinds of aerosol data available from satellite.
Aerosol Optical Thickness
1.0
0.8
0.6
0.4
0.2
0.0
Spring
Summer
Fall
Winter
Haze & Pollution
Dust
Pollution & dust
There are many satellites capable of global and partial global measurements each day. Here you can see visually the product call AOD (Aerosol Optical Depth) which is an optical measurement of total column aerosol.
Biomass Burning
Several satellites provide state-of-art aerosol measurements over global region on daily basis

19. Aerosols Transported Across the Atlantic
Global Coverage Helps Us to Estimate Transport and Source Regions
Dust
Smoke
Combined use of several satellite sensors can help us to make fairly good estimates of aerosol sources, sinks and types.
Aerosols Transported Across the Atlantic

20. Earth Satellite Observations Advantages
Air Quality/Pollution
Provides coverage where there are no ground monitors
Synoptic and trans-boundary view (time and space)
Visual context
Qualitative assessments and indications of long range transport
Adds value when combined with surface monitors and models
This is a summary of the main advantages of using satellite data products.

21. Earth Satellite Observations
Limitations
Temporal Coverage
Vertical Resolution of Pollutants
Lack of Near Surface Sensitivity
Lack of specific identification of pollutant type
Satellite measurements and sensors have many limitations which impact their ability to be used in air quality applications. These are the main ones that we will consider.

22. Common types of orbits Geostationary Polar Polar orbiting orbit
fixed circular orbit above the earth, ~ km in sun synchronous orbit with orbital pass at about same local solar time each day
Geostationary orbit
An orbit that has the same Earth’s rotational period
Appears ‘fixed’ above earth Satellite on equator at ~36,000km
Here we begin to introduce some of the technical aspects of satellites and satellite sensors to help us understand their limitations in air quality work.

23. Observation Frequency
Polar orbiting satellites – observations per day per sensor
- Geostationary
observations
- Polar observations
Most of the remote sensing satellites currently used for air quality work are in polar orbit. This generally limits them to two local observations per day as represented by the red vertical lines on the time graph. The points on the horizontal lines show the observational frequency of geostationary satellites. Geostationary observations up to this point have been of poor quality in comparison to the polar satellites limiting their use for air quality applications. This should begin to change of the next few years with the launch of geostationary satellites which have been designed for air quality work.
Geostationary satellites – product quality is lacking in many locations

24. Remote Sensing …Sensors
Passive Sensors: Remote sensing systems which measure energy that is naturally available are called passive sensors.
Active Sensors: The sensor emits radiation which is directed toward the target to be investigated. The radiation reflected from that target is detected and measured by the sensor.

25. Limitations of Satellite Data
Almost all satellite sensors are passive sensors.
Passive sensors measure the entire column.
Column measurements may or may not
reflect what is happening at ground level.
This is true whether we are measuring aerosols or trace gasses.

26. Lidar Insturments Can Resolve Veritcal Distribution
Here is an example of data taken from the CALIPSO sensor which is represented as a curtain superimposed on the surface of the earth. As you can see it is sensitive to changes in the vertical column of the atmosphere.

27. Principal Satellites in Air Quality Remote Sensing
380 Km
MISR
1Km
Calipso
Space Borne
Lidar
Here is a comparison of the spatial coverage across the surface of the earth from the most common satellite sensors used in air quality. The Calipso sensor is severely limited in its spatial coverage.
2300 Km MODIS
2400 Km OMI

28. Satellites Vs Sensors Aura Satellite Four Instruments: OMI TES HIRDLS
Earth-observing satellite remote sensing instruments are named according to
1) the satellite (also called platform)
2) the instrument (also called sensor)
Six Instruments:
MODIS
CERES
AIRS
AMSU-A
AMSR-E
HSB
Four Instruments:
OMI
TES
HIRDLS
MLS
Aura Satellite
Aqua Satellite

29. Primary Sensors - AEROSOLS
MODIS
MODerate resolution Imaging SpectroRadiometer
Measures total column aerosol
AOD - Aerosol Optical Depth
MISR
Multi-angle Imaging SpectroRadiometer
AOD
Particle Type
Since some terms are so integral to what we will be talking about it is important to introduce early on the primary sensors. MODIS (MODerate-resolution Imaging Spectro-radiometer) is the primary sensor for aerosol measurements. It makes an optical measurement from which we infer the total column aerosol amount. OMI (Ozone Monitoring Instrument) is the primary NASA instrument for trace gas measurements. It can also measure aerosols.
VIIRS
Visible Infrared Imaging Radiometer Suite
AOD
Particle Type

30. Primary Sensors – Trace Gases
OMI
Ozone Monitoring Instrument
AIRS
Atmosphere Infrared Sounder
Since some terms are so integral to what we will be talking about it is important to introduce early on the primary sensors. MISR (Multi-angle Imaging Spectroradiometer).
AIRS (Atmospheric InfraRed Sounder).

31. Instrument Capabilities – for Air Quality
Radiometers
Imagers
MODIS – Terra and Aqua
250m-1 KM Resolution
MISR
275m- 1.1 KM Resolution
VIIRS
6 KM Resolution
OMI –
13 x 24 KM Resolution
GOME-2
40 x 80 KM Resolution
SCIAMACHY
30 x 60 KM Resolution
There are many ways of grouping remote sensing satellites: Orbit, sensor type, sensor function etc.

32. Imagers & Sounders Imagers create images – MODIS, MISR
Active and passive sounders can provide vertical profiles – Cloud Profiling Radar (CLOUDSAT)
SAR (Synthetic Aperture RADAR)
Atmospheric Infrared Sounder (AIRS)

33. Satellite/Sensor Classifications
Some of the ways satellites/sensor can be classified
Orbits
Polar vs Geostationary
Energy source
Passive vs Active …
Solar spectrum
Visible, UV, IR, Microwave …
Measurement Technique
Scanning, non-scanning, imager, sounders …
Resolution (spatial, temporal, spectral, radiometric)
Low vs high (any of the kind)
Applications
Weather, Ocean colors, Land mapping, Atmospheric Physics, Atmospheric Chemistry, Air quality, radiation budget, water cycle, coastal management …

34. Ascending vs Descending
Polar Orbits

35. Approximately 1:30 PM local overpass time Afternoon Satellite
MODIS-Aqua (“ascending” orbit)
Approximately 1:30 PM local overpass time Afternoon Satellite
MODIS-Terra (“descending”)
Approximately 10:30 AM local overpass time
Morning Satellite 35

36. Pause for Questions Important Note:
Passive instruments measure reflected/emitted radiance at the top-of-atmosphere.
All other information is derived from this and some ancillary data.

37. The Remote Sensing Process and Sensor Measurements

38. Remote sensing instrument measures reflected or emitted radiation
“the art, science, and technology of obtaining reliable information about physical objects and the environment, through the process of recording, measuring and interpreting imagery and digital representations of energy patterns derived from noncontact sensor systems”. (Cowell 1997).
A remote sensing instrument collects information about an object or phenomenon within the IFOV of the sensor system without being in direct physical contact with it. The sensor is located on a suborbital or satellite platform.

39. Remote Sensing Process
(A)
Energy Source or Illumination
Transmission, Reception, and Processing (E) 
(D)
Recording of Energy by the Sensor 
Interpretation and Analysis (F)
(B)
Radiation and the Atmosphere
Energy Source or Illumination (A) the first requirement for remote sensing is to have an energy source which illuminates or provides electromagnetic energy to the target of interest.
Radiation and the Atmosphere (B) - as the energy travels from its source to the target, it will come in contact with and interact with the atmosphere it passes through. This interaction may take place a second time as the energy travels from the target to the sensor.
 Interaction with the Target (C) - once the energy makes its way to the target through the atmosphere, it interacts with the target depending on the properties of both the target and the radiation
Recording of Energy by the Sensor (D) - after the energy has been scattered by, or emitted from the target, we require a sensor (remote - not in contact with the target) to collect and record the electromagnetic radiation.
Transmission, Reception, and Processing (E) - the energy recorded by the sensor has to be transmitted, often in electronic form, to a receiving and processing station where the data are processed into an image (hardcopy and/or digital)
Interpretation and Analysis (F) - the processed image is interpreted, visually and/or digitally or electronically, to extract information about the target which was illuminated.
Application (G) - the final element of the remote sensing process is achieved when we apply the information we have been able to extract from the imagery about the target in order to better understand it, reveal some new information, or assist in solving a particular problem
(C)
 Interaction with the Target  
Application (G) 
Reference: CCRS/CCT

40. Remote Sensing Process
(A)
Energy Source or Illumination
(D)
Recording of Energy by the Sensor 
(E)
Transmission, Reception, and Processing
Interpretation and Analysis (F)
(B)
Radiation and the Atmosphere
(F)
Interpretation and Analysis
Energy Source or Illumination (A) the first requirement for remote sensing is to have an energy source which illuminates or provides electromagnetic energy to the target of interest.
Radiation and the Atmosphere (B) - as the energy travels from its source to the target, it will come in contact with and interact with the atmosphere it passes through. This interaction may take place a second time as the energy travels from the target to the sensor.
 Interaction with the Target (C) - once the energy makes its way to the target through the atmosphere, it interacts with the target depending on the properties of both the target and the radiation
Application (G) - the final element of the remote sensing process is achieved when we apply the information we have been able to extract from the imagery about the target in order to better understand it, reveal some new information, or assist in solving a particular problem
Recording of Energy by the Sensor (D) - after the energy has been scattered by, or emitted from the target, we require a sensor (remote - not in contact with the target) to collect and record the electromagnetic radiation.
Transmission, Reception, and Processing (E) - the energy recorded by the sensor has to be transmitted, often in electronic form, to a receiving and processing station where the data are processed into an image (hardcopy and/or digital)
Interpretation and Analysis (F) - the processed image is interpreted, visually and/or digitally or electronically, to extract information about the target which was illuminated.
(C)
 Interaction with the Target  
Reference: CCRS/CCT

41. Remote Sensing Process
Energy Source or Illumination (A)
Recording of Energy by the Sensor (D) 
Transmission, Reception, and Processing (E) 
Interpretation and Analysis (F)
Radiation and the Atmosphere (B) 
Energy Source or Illumination (A) the first requirement for remote sensing is to have an energy source which illuminates or provides electromagnetic energy to the target of interest.
Radiation and the Atmosphere (B) - as the energy travels from its source to the target, it will come in contact with and interact with the atmosphere it passes through. This interaction may take place a second time as the energy travels from the target to the sensor.
 Interaction with the Target (C) - once the energy makes its way to the target through the atmosphere, it interacts with the target depending on the properties of both the target and the radiation
Application (G) - the final element of the remote sensing process is achieved when we apply the information we have been able to extract from the imagery about the target in order to better understand it, reveal some new information, or assist in solving a particular problem
Recording of Energy by the Sensor (D) - after the energy has been scattered by, or emitted from the target, we require a sensor (remote - not in contact with the target) to collect and record the electromagnetic radiation.
Transmission, Reception, and Processing (E) - the energy recorded by the sensor has to be transmitted, often in electronic form, to a receiving and processing station where the data are processed into an image (hardcopy and/or digital)
Interpretation and Analysis (F) - the processed image is interpreted, visually and/or digitally or electronically, to extract information about the target which was illuminated.
(G)
Application
 Interaction with the Target (C) 
Reference: CCRS/CCT

42. Remote Sensing – Resolutions
Spatial resolution
The smallest spatial measurement.
Temporal resolution
Frequency of measurement.
Spectral resolution
The number of independent channels.
Radiometric resolution
The sensitivity of the detectors.
These parameters are essential background information for really understanding the capabilities of the satellites and their products and product quality.

43. Pixel pixels - the smallest units of an image.
Image pixels are normally square (but not necessary) and represent a certain area on an image/Earth.

44. Spatial Resolution Spatial Resolution :
The highest magnification of the sensor at the ground surface
Satellite images are organized in rows and column called raster imagery and each pixel has a certain spatial resolution.
Off-nadir pixel size
FOV
IFOV
Satellite
height
Note that at nadir the pixel size is finer and for large swath width sensors such as MODIS and AVHRR the pixel size at the edge of the swath is much larger.
Nadir pixel size
increasing pixel size
bow-tie effect
Flight direction
Scan direction

45. Why is spatial resolution important ?

46. Spectral Resolution
Spectral resolution describes the ability of a sensor to define fine wavelength intervals. The finer the spectral resolution, the narrower the wavelength range for a particular channel or band.
multi-spectral sensors  - MODIS
hyper spectral sensors - OMI, AIRS

47.
Wavelength (nm)
In order to capture information contained in a narrow spectral region – hyper spectral instruments such as OMI, or AIRS are required

48. Radiometric Resolution
Imagery data are represented by positive digital numbers which vary from 0 to (one less than) a selected power of 2.
The maximum number of brightness levels available depends on the number of bits used in representing the energy recorded.
12 bit sensor (MODIS, MISR) – 212 or 4096 levels
10 bit sensor (AVHRR) – 210 or 1024 levels
8 bit sensor (Landsat TM) – or 256 levels (0-255)
6 bit sensor (Landsat MSS) – or 64 levels (0-63)

49. Radiometric Resolution
4 - levels
2 - levels
16 - levels
8 - levels
 In classifying a scene, different classes are more precisely identified if radiometric precision is high.

50. Temporal Resolution
How frequently a satellite can provide observation of same area on the earth
It mostly depends on swath width of the satellite – larger the swath – higher the temporal resolution
MODIS – 1-2 days – 16 day repeat cycle
OMI – 1-2 days
MISR – 6-8 days
Geostationary – 15 min to 1 hour
(but limited to one specific area of the globe)

51. Remote Sensing – Trade offs
MODIS 500 Meter
True color image
Aster Image
15 M Resolution

52. Remote Sensing – Trade offs
2300 KM
60 KM
MODIS 500 Meter
True color image
The different resolutions are the limiting factor for the utilization of the remote sensing data for different applications. Trade off is because of technical constraints.
Larger swath is associated with low spatial resolution and vice versa
Therefore, often satellites designs are applications oriented

53. Trade Offs
It is very difficult to obtain extremely high spectral, spatial, temporal and radiometric resolutions at the same time
MODIS, OMI and several other sensors can obtain global coverage every one – two days because of their wide swath width
Higher resolution polar orbiting satellites may take 8 – 16 days for global coverage or may never provide full coverage of the globe.
Geostationary satellites obtain much more frequent observations but at lower resolution
due to the much greater orbital distance.

54. Factors which change with each instrument
Calibration accuracy
Quality Assurance
Data formats
Product Resolutions
Level of data products
Current release of the data and data history

55. Geophysical Products Images Cloud Fraction
Aerosol Optical Depth – Particulate Matter
Total Column Trace Gas Amount
Trace Gas Layer Concentrations
Land Cover Type
Vegetation Index

56. Assignment Week - 1