This document discusses different coordinate systems and datums, and how to ensure GPS data aligns properly in a GIS. It identifies latitude and longitude, and Universal Transverse Mercator (UTM) as common coordinate systems. It also discusses different datums like NAD27, NAD83 and WGS84, and how over time datums have shifted, requiring datum adjustments. The key to properly aligning GPS data in a GIS is to verify the reference frame of the GPS data, identify the GIS datum, and apply the correct datum transformation when exporting or importing data.
The main focus of this presentation is on coordinate systems. We describe common problems that people have, key terms , how to apply coordinate systems in 10.1 and best practices.
The GPS system uses 24 satellites in six orbital planes to provide positioning and timing services to users. Signals from at least four satellites are used to determine a user's location through calculations of distances and signal propagation times. The system consists of space, control, and user segments. The space segment comprises the GPS satellites. The control segment monitors satellite health and uploads corrections. The user segment receives and uses positioning and timing data.
The document provides information about the Global Positioning System (GPS). It describes the three segments that make up GPS: the space segment consisting of 24 satellites in six orbital planes, the control segment that monitors the satellites, and the user segment that receives and uses the GPS signals. It then explains some of the technical details of how GPS determines user position using timing signals from multiple satellites.
The document provides information about the Global Positioning System (GPS). It describes the three segments that make up GPS: the space segment consisting of 24 satellites in six orbital planes, the control segment that monitors the satellites, and the user segment that receives and uses the GPS signals. It then explains some of the technical details of how GPS determines user position using timing signals from multiple satellites and triangulation calculations.
The document provides information about the Global Positioning System (GPS). It describes the three segments that make up GPS: the space segment consisting of 24 satellites in six orbital planes, the control segment that monitors the satellites, and the user segment that receives and uses the GPS signals. It then explains some of the technical details of how GPS determines user position using timing signals from multiple satellites and triangulation calculations.
GNSS/GPS systems enable precise positioning using signals from satellites. Consumer-grade receivers provide positions within 5 meters, while survey-grade systems can achieve precision of a few centimeters with post-processing. Earth scientists use GNSS to track ground movement, map topography, and monitor hazards, providing both direct benefits like early warning systems and indirect benefits like furthering scientific understanding.
GNSS/GPS systems enable precise positioning using signals from satellites. Consumer-grade receivers provide positions within 5 meters, while survey-grade systems can achieve precision of a few centimeters with post-processing. Earth scientists use GNSS to track ground movement, map topography, and monitor hazards, providing both direct benefits like early warning systems and indirect benefits like furthering scientific understanding.
The main focus of this presentation is on coordinate systems. We describe common problems that people have, key terms , how to apply coordinate systems in 10.1 and best practices.
The GPS system uses 24 satellites in six orbital planes to provide positioning and timing services to users. Signals from at least four satellites are used to determine a user's location through calculations of distances and signal propagation times. The system consists of space, control, and user segments. The space segment comprises the GPS satellites. The control segment monitors satellite health and uploads corrections. The user segment receives and uses positioning and timing data.
The document provides information about the Global Positioning System (GPS). It describes the three segments that make up GPS: the space segment consisting of 24 satellites in six orbital planes, the control segment that monitors the satellites, and the user segment that receives and uses the GPS signals. It then explains some of the technical details of how GPS determines user position using timing signals from multiple satellites.
The document provides information about the Global Positioning System (GPS). It describes the three segments that make up GPS: the space segment consisting of 24 satellites in six orbital planes, the control segment that monitors the satellites, and the user segment that receives and uses the GPS signals. It then explains some of the technical details of how GPS determines user position using timing signals from multiple satellites and triangulation calculations.
The document provides information about the Global Positioning System (GPS). It describes the three segments that make up GPS: the space segment consisting of 24 satellites in six orbital planes, the control segment that monitors the satellites, and the user segment that receives and uses the GPS signals. It then explains some of the technical details of how GPS determines user position using timing signals from multiple satellites and triangulation calculations.
GNSS/GPS systems enable precise positioning using signals from satellites. Consumer-grade receivers provide positions within 5 meters, while survey-grade systems can achieve precision of a few centimeters with post-processing. Earth scientists use GNSS to track ground movement, map topography, and monitor hazards, providing both direct benefits like early warning systems and indirect benefits like furthering scientific understanding.
GNSS/GPS systems enable precise positioning using signals from satellites. Consumer-grade receivers provide positions within 5 meters, while survey-grade systems can achieve precision of a few centimeters with post-processing. Earth scientists use GNSS to track ground movement, map topography, and monitor hazards, providing both direct benefits like early warning systems and indirect benefits like furthering scientific understanding.
The document discusses key concepts about GPS (Global Positioning System) including:
1. GPS has three segments - the control segment controls the satellites from ground stations, the space segment consists of 24 satellites that transmit signals, and the user segment are the GPS receivers that receive signals to determine location.
2. GPS uses trilateration based on the time it takes signals from multiple satellites to reach the receiver to calculate the user's position. Accuracy depends on factors like receiver quality and atmospheric conditions.
3. Sources of error include satellite and receiver clocks, atmospheric delays, multipath interference, and satellite geometry which is measured by dilution of precision (DOP). Differential GPS can improve accuracy to 1-3 meters.
Coordinate systems define locations on Earth and enable datasets to integrate spatially. There are two main types: geographic coordinate systems use latitude and longitude, while projected coordinate systems define planar coordinates like x and y distances to allow for measurement. When data in different coordinate systems is viewed together in GIS, on-the-fly projection converts between systems to align the data spatially. Geographic transformations define the mathematical operations for converting coordinate values between geographic coordinate systems.
coordinate systems map projections and graphical and atoms ppt group (B).pptxBakhtAli10
This document discusses coordinate systems, geodetic datums, and map projections. It defines coordinate systems as reference frameworks that represent locations using geographic or projected coordinates. Geographic coordinate systems (GCS) use latitude and longitude on a spherical surface, while projected coordinate systems (PCS) map the curved Earth onto a flat plane. Geodetic datums provide coordinate systems for mapping and navigation by modeling the Earth's shape and size. The document also explains common map projections that transform the globe onto flat surfaces, including conic, cylindrical, and planar projections.
ANALYSIS OF GPS ERRORS DURING DIFFERENT TIMES IN A DAY IJORCS
This document analyzes GPS errors that occur during different times of the day. GPS accuracy is affected by ionospheric errors. Data was collected in Hyderabad, India using a GPS receiver. Errors were observed to vary between morning, afternoon, and evening. Morning errors were highest and gradually increased. Afternoon errors were fewer and gradually decreased. Evening errors were larger than afternoon but smaller than morning. Converting GPS coordinates from WGS-84 to UTM format introduced additional errors.
Map projections allow the representation of locations on the spherical Earth on a flat surface by transforming geospatial coordinates using mathematical formulas. There are different types of map projections that preserve various geometric properties to differing degrees, such as distance, shape, or direction. It is important to choose a projection and coordinate system that suit the intended mapping purpose. Coordinate systems use datums to define relationships between coordinates and locations on the Earth's irregular surface.
This document outlines the syllabus for a course on Geographic Information Systems (GIS). It is divided into 5 units that cover fundamentals of GIS, spatial data models, data input and topology, data analysis, and applications of GIS. The objectives of the course are to introduce students to the basic concepts of GIS and provide an understanding of spatial data structures, management processes, and analysis tools.
This document outlines the syllabus for a course on Geographic Information Systems (GIS). The course is divided into 5 units that cover fundamentals of GIS, spatial data models, data input and topology, data analysis, and applications of GIS. The objectives are to introduce GIS fundamentals and processes of data management, analysis, and output. Students will learn about spatial data structures, data quality standards, and tools for data input, analysis, and management. The course aims to provide knowledge of GIS concepts and techniques.
GPS is a satellite-based navigation system that provides location and time information to users worldwide. It uses a constellation of 24 satellites and trilateration techniques to determine the user's position by calculating distances to four or more satellites. Sources of error include atmospheric conditions and satellite clock errors, but differential GPS and systems like WAAS can achieve accuracy of 3 meters or better for civilian users.
This document discusses map projections and their use in GIS. It begins by explaining that map projections are needed to portray the spherical Earth on a flat surface, and that coordinate reference systems define the relationship between projected maps and real-world locations. It then discusses different types of map projections, including their advantages and disadvantages. Specifically, it covers conformal, equal-distance, and equal-area projections. It also discusses terminology like datum, spheroid, and false northing/easting values. Finally, it provides guidance on choosing a suitable projection and properly assigning projections in GIS projects.
This document discusses Global Navigation Satellite Systems (GNSS) such as GPS, GLONASS, Galileo, and others. It provides details on:
- The components and history of GPS, including its space, ground, and user segments. GPS uses satellites and signals to determine position globally.
- How GPS works by using satellite ranging, precise timing from atomic clocks, and trilateration to calculate a user's position. It requires at least 4 satellites.
- Applications of GPS technology including navigation, mapping, timing, and tracking of people and assets. GPS is used widely in aviation, maritime, agriculture, and other areas.
This document is a certificate and report submitted by Harshit Bansal for their class project on the Global Positioning System (GPS). It includes an acknowledgement of their physics teacher, an index of topics to be covered, and sections on the introduction to GPS, the concept of using satellite signals and trilateration to determine position, how additional satellites improve accuracy, and common sources of error. The report provides an overview of how GPS works to allow devices to calculate their location using signals from multiple satellites.
The Global Positioning System (GPS) is a satellite-based navigation system that provides precise 3D location information around the world. It consists of 24 satellites orbiting 20,200 km above the Earth that transmit radio signals. GPS receivers on the ground use these signals to calculate the user's position by triangulating distances to four or more satellites. The system is operated and maintained by the U.S. Department of Defense.
This document discusses differential GPS (DGPS), which improves the accuracy of GPS positioning. It works by using a stationary GPS receiver at a known location to calculate error corrections, which are transmitted to a roving receiver to improve its position accuracy. DGPS can reduce GPS errors from sources like atmospheric delays, satellite orbit issues, and multipath effects, providing sub-meter accuracy compared to the 5-10 meter accuracy of standard GPS. It allows real-time position correction or post-processed correction through data from a fixed base station.
Global positioning system and geographic information system.pptxVamsiKrishna767673
This document provides an overview of the history and components of GPS (Global Positioning System) and other global satellite navigation systems. It discusses the development and operation of GPS satellites, ground control stations, and user receivers. Key points covered include how satellite positioning is determined via signal timing, types of errors that can occur, and methods for improving accuracy like differential correction via local reference stations or satellite-based systems like WAAS. Diagrams illustrate concepts like satellite geometry, atmospheric effects, multipath errors, and how differential systems work.
GPS uses satellites to allow receivers to determine their precise location and time. It consists of 3 segments - space, control, and user. The space segment has 24 satellites that continuously transmit navigation data. The control segment generates ephemeris and clock data and uploads to satellites. For the user segment, receivers measure pseudorange and phase to calculate 3D position, velocity, and time with accuracy of meters. Key advantages are high precision, speed, and automation compared to traditional surveying methods.
This document discusses databases and geographic information systems (GIS). It explains that a database consists of tables of structured data that follow rules and can be linked together through relationships. GIS systems use spatial databases where tables contain geographic location information in addition to other fields. Proper database design is important. The document also covers topics like map datums, projections, and how geographic coordinates can vary depending on the reference system used.
This document discusses map projections and coordinate systems in GIS. It explains that there are two main types of coordinate systems: geographic and projected. Geographic coordinate systems use spherical coordinates to identify Earth surface features, while projected coordinate systems use planar coordinates to identify features by projecting them onto a flat surface. It also discusses datums, which provide a reference framework for measuring locations on the Earth's surface, as well as how map projections introduce distortions like changes to shape, area, distance and direction when converting from a spherical to planar surface.
A Visual Guide to 1 Samuel | A Tale of Two HeartsSteve Thomason
These slides walk through the story of 1 Samuel. Samuel is the last judge of Israel. The people reject God and want a king. Saul is anointed as the first king, but he is not a good king. David, the shepherd boy is anointed and Saul is envious of him. David shows honor while Saul continues to self destruct.
The document discusses key concepts about GPS (Global Positioning System) including:
1. GPS has three segments - the control segment controls the satellites from ground stations, the space segment consists of 24 satellites that transmit signals, and the user segment are the GPS receivers that receive signals to determine location.
2. GPS uses trilateration based on the time it takes signals from multiple satellites to reach the receiver to calculate the user's position. Accuracy depends on factors like receiver quality and atmospheric conditions.
3. Sources of error include satellite and receiver clocks, atmospheric delays, multipath interference, and satellite geometry which is measured by dilution of precision (DOP). Differential GPS can improve accuracy to 1-3 meters.
Coordinate systems define locations on Earth and enable datasets to integrate spatially. There are two main types: geographic coordinate systems use latitude and longitude, while projected coordinate systems define planar coordinates like x and y distances to allow for measurement. When data in different coordinate systems is viewed together in GIS, on-the-fly projection converts between systems to align the data spatially. Geographic transformations define the mathematical operations for converting coordinate values between geographic coordinate systems.
coordinate systems map projections and graphical and atoms ppt group (B).pptxBakhtAli10
This document discusses coordinate systems, geodetic datums, and map projections. It defines coordinate systems as reference frameworks that represent locations using geographic or projected coordinates. Geographic coordinate systems (GCS) use latitude and longitude on a spherical surface, while projected coordinate systems (PCS) map the curved Earth onto a flat plane. Geodetic datums provide coordinate systems for mapping and navigation by modeling the Earth's shape and size. The document also explains common map projections that transform the globe onto flat surfaces, including conic, cylindrical, and planar projections.
ANALYSIS OF GPS ERRORS DURING DIFFERENT TIMES IN A DAY IJORCS
This document analyzes GPS errors that occur during different times of the day. GPS accuracy is affected by ionospheric errors. Data was collected in Hyderabad, India using a GPS receiver. Errors were observed to vary between morning, afternoon, and evening. Morning errors were highest and gradually increased. Afternoon errors were fewer and gradually decreased. Evening errors were larger than afternoon but smaller than morning. Converting GPS coordinates from WGS-84 to UTM format introduced additional errors.
Map projections allow the representation of locations on the spherical Earth on a flat surface by transforming geospatial coordinates using mathematical formulas. There are different types of map projections that preserve various geometric properties to differing degrees, such as distance, shape, or direction. It is important to choose a projection and coordinate system that suit the intended mapping purpose. Coordinate systems use datums to define relationships between coordinates and locations on the Earth's irregular surface.
This document outlines the syllabus for a course on Geographic Information Systems (GIS). It is divided into 5 units that cover fundamentals of GIS, spatial data models, data input and topology, data analysis, and applications of GIS. The objectives of the course are to introduce students to the basic concepts of GIS and provide an understanding of spatial data structures, management processes, and analysis tools.
This document outlines the syllabus for a course on Geographic Information Systems (GIS). The course is divided into 5 units that cover fundamentals of GIS, spatial data models, data input and topology, data analysis, and applications of GIS. The objectives are to introduce GIS fundamentals and processes of data management, analysis, and output. Students will learn about spatial data structures, data quality standards, and tools for data input, analysis, and management. The course aims to provide knowledge of GIS concepts and techniques.
GPS is a satellite-based navigation system that provides location and time information to users worldwide. It uses a constellation of 24 satellites and trilateration techniques to determine the user's position by calculating distances to four or more satellites. Sources of error include atmospheric conditions and satellite clock errors, but differential GPS and systems like WAAS can achieve accuracy of 3 meters or better for civilian users.
This document discusses map projections and their use in GIS. It begins by explaining that map projections are needed to portray the spherical Earth on a flat surface, and that coordinate reference systems define the relationship between projected maps and real-world locations. It then discusses different types of map projections, including their advantages and disadvantages. Specifically, it covers conformal, equal-distance, and equal-area projections. It also discusses terminology like datum, spheroid, and false northing/easting values. Finally, it provides guidance on choosing a suitable projection and properly assigning projections in GIS projects.
This document discusses Global Navigation Satellite Systems (GNSS) such as GPS, GLONASS, Galileo, and others. It provides details on:
- The components and history of GPS, including its space, ground, and user segments. GPS uses satellites and signals to determine position globally.
- How GPS works by using satellite ranging, precise timing from atomic clocks, and trilateration to calculate a user's position. It requires at least 4 satellites.
- Applications of GPS technology including navigation, mapping, timing, and tracking of people and assets. GPS is used widely in aviation, maritime, agriculture, and other areas.
This document is a certificate and report submitted by Harshit Bansal for their class project on the Global Positioning System (GPS). It includes an acknowledgement of their physics teacher, an index of topics to be covered, and sections on the introduction to GPS, the concept of using satellite signals and trilateration to determine position, how additional satellites improve accuracy, and common sources of error. The report provides an overview of how GPS works to allow devices to calculate their location using signals from multiple satellites.
The Global Positioning System (GPS) is a satellite-based navigation system that provides precise 3D location information around the world. It consists of 24 satellites orbiting 20,200 km above the Earth that transmit radio signals. GPS receivers on the ground use these signals to calculate the user's position by triangulating distances to four or more satellites. The system is operated and maintained by the U.S. Department of Defense.
This document discusses differential GPS (DGPS), which improves the accuracy of GPS positioning. It works by using a stationary GPS receiver at a known location to calculate error corrections, which are transmitted to a roving receiver to improve its position accuracy. DGPS can reduce GPS errors from sources like atmospheric delays, satellite orbit issues, and multipath effects, providing sub-meter accuracy compared to the 5-10 meter accuracy of standard GPS. It allows real-time position correction or post-processed correction through data from a fixed base station.
Global positioning system and geographic information system.pptxVamsiKrishna767673
This document provides an overview of the history and components of GPS (Global Positioning System) and other global satellite navigation systems. It discusses the development and operation of GPS satellites, ground control stations, and user receivers. Key points covered include how satellite positioning is determined via signal timing, types of errors that can occur, and methods for improving accuracy like differential correction via local reference stations or satellite-based systems like WAAS. Diagrams illustrate concepts like satellite geometry, atmospheric effects, multipath errors, and how differential systems work.
GPS uses satellites to allow receivers to determine their precise location and time. It consists of 3 segments - space, control, and user. The space segment has 24 satellites that continuously transmit navigation data. The control segment generates ephemeris and clock data and uploads to satellites. For the user segment, receivers measure pseudorange and phase to calculate 3D position, velocity, and time with accuracy of meters. Key advantages are high precision, speed, and automation compared to traditional surveying methods.
This document discusses databases and geographic information systems (GIS). It explains that a database consists of tables of structured data that follow rules and can be linked together through relationships. GIS systems use spatial databases where tables contain geographic location information in addition to other fields. Proper database design is important. The document also covers topics like map datums, projections, and how geographic coordinates can vary depending on the reference system used.
This document discusses map projections and coordinate systems in GIS. It explains that there are two main types of coordinate systems: geographic and projected. Geographic coordinate systems use spherical coordinates to identify Earth surface features, while projected coordinate systems use planar coordinates to identify features by projecting them onto a flat surface. It also discusses datums, which provide a reference framework for measuring locations on the Earth's surface, as well as how map projections introduce distortions like changes to shape, area, distance and direction when converting from a spherical to planar surface.
A Visual Guide to 1 Samuel | A Tale of Two HeartsSteve Thomason
These slides walk through the story of 1 Samuel. Samuel is the last judge of Israel. The people reject God and want a king. Saul is anointed as the first king, but he is not a good king. David, the shepherd boy is anointed and Saul is envious of him. David shows honor while Saul continues to self destruct.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
CapTechTalks Webinar Slides June 2024 Donovan Wright.pptxCapitolTechU
Slides from a Capitol Technology University webinar held June 20, 2024. The webinar featured Dr. Donovan Wright, presenting on the Department of Defense Digital Transformation.
🔥🔥🔥🔥🔥🔥🔥🔥🔥
إضغ بين إيديكم من أقوى الملازم التي صممتها
ملزمة تشريح الجهاز الهيكلي (نظري 3)
💀💀💀💀💀💀💀💀💀💀
تتميز هذهِ الملزمة بعِدة مُميزات :
1- مُترجمة ترجمة تُناسب جميع المستويات
2- تحتوي على 78 رسم توضيحي لكل كلمة موجودة بالملزمة (لكل كلمة !!!!)
#فهم_ماكو_درخ
3- دقة الكتابة والصور عالية جداً جداً جداً
4- هُنالك بعض المعلومات تم توضيحها بشكل تفصيلي جداً (تُعتبر لدى الطالب أو الطالبة بإنها معلومات مُبهمة ومع ذلك تم توضيح هذهِ المعلومات المُبهمة بشكل تفصيلي جداً
5- الملزمة تشرح نفسها ب نفسها بس تكلك تعال اقراني
6- تحتوي الملزمة في اول سلايد على خارطة تتضمن جميع تفرُعات معلومات الجهاز الهيكلي المذكورة في هذهِ الملزمة
واخيراً هذهِ الملزمة حلالٌ عليكم وإتمنى منكم إن تدعولي بالخير والصحة والعافية فقط
كل التوفيق زملائي وزميلاتي ، زميلكم محمد الذهبي 💊💊
🔥🔥🔥🔥🔥🔥🔥🔥🔥
3. Setting The Stage
• GPS is rigid – collects one way
• GIS is flexible – designed to share
• #1 reason GPS data doesn’t line up in
GIS - coordinate system/datum mismatch
• How do we fix it? – Educate
5. Lat / Long Coordinate System
Latitude
Parallels of latitude
0° latitude
north
latitude
south
latitude
90°N
equator
6. Lat / Long Coordinate System
Longitude
West
Longitude
Meridians of longitude 0° longitude
Prime Meridian
East
longitude
Grenwich, England
7. UTM Coordinate Systems
Allows projection of a
spherical surface onto a
flat surface
A plane coordinate system to
relate the coordinates of points
on earth’s curved surface with
the coordinates of the same
points on a plane or flat surface
8. UTM Zones in North America
174
180 168 162 156 150 144 138 132 126 120 114 108 102 96 90 78 72 54
60
66
84 48
9. “Figure” of the Earth
Best-fit ellipsoid
(e.g., GRS-80, WGS-84)
10. Datum and Ellipsoids
• Datum - represented by ellipsoid
• Reference ellipsoid examples:
• Clarke 1866
• GRS 80
• WGS 84
12. NAD27: Clarke 1866 ellipsoid
origin in Kansas
Datum Origin
on Surface of
Earth
Ellipsoid Model
based on less
precise surveys
13. NAD27: Leaving Behind
• Invented Space Travel
• Increasing accuracy of
surveys
• Shift from optical surveys to
a mathematical model of the
Earths shape
• The result is a specific point
on the landscape can take
on multiple meanings
14. GPS Datum: WGS 84
Origin is at the Earth’s center of mass (geocentric)
This is the datum used for the NAVSTAR GPS satellites
15. WGS84: WGS84 ellipsoid
origin center of earth
The origins of the
WGS84 and
NAD83 ellipsoids
are at the center of
the earth’s mass,
which makes them
ideal for a GPS
datum
16. Datum Adjustments
• Known as Datum Adjustments or Epochs
• WGS84 (G1150) – most current version
• “Original” NAD83 = NAD83 (1986)
– NAD83 (1992)
– NAD83 (2002)
– ……
• Most Current NAD83
– NAD83 (CORS96) (Epoch 2003.00)
21. Reference Frames
• Differentially corrected GPS data are
always in terms of the corrections
source’s reference frame.
• In Arcata we are using CORS station
data and therefore must apply the
correct datum transform between the
GPS data and your GIS
22. Mapping / Coordinate System
• For Arcata BLM Office in Pathfinder
Office
Coordinate System: UTM Zone 10N
Datum: NAD 83 (CONUS) CORS96
23. Reason Were Using NAD83
(CONUS) CORS96
GIS In NAD83
Using CORS96
CORS
ITRF00
24. When Do Datums/Coordinate
Systems Matter?
• PFO Map View
– Coordinate system
• Terrasync
– Coordinate System
• Export Utility
– Shape Export
Coordinate System
• ArcGIS Catalog
– Define Projection
• ArcGIS
– Data Frame Properties
– Coordinate System
Tab
25. GPS Datum Tips
• Summary:
–Check, check, check
–ASK your GIS Specialist
• Good handouts in <cd>/references
26. Conclusion
• Now that you’ve learned there are
differences it will be important that
you learn how to…
• Make it Match
–Pre-Field Day 2
• Datum Transforms
–Friday’s Test against Truth
33. 33
Taking “GIS” out in the Field
• Rasters
• Vectors
• All require a projection (coordinate
system) defined ahead of time
34. 34
Matching Data Steps
• Know what it is – Metadata helps
• Tell Pathfinder Office the correct
Datum and Coordinate System
35. 35
When Do Datums/Coordinate
Systems Matter?
• PFO Map View
– Coordinate system
• Terrasync
– Coordinate System
• Export Utility
– Shape Export
Coordinate System
• ArcGIS Catalog
– Define Projection
• ArcGIS
– Data Frame Properties
– Coordinate System
Tab
36. 36
Today’s Background Image
• Humboldt Campus Map
–PDF obtained from Website
–Converted to TIFF
–Co-registered 12 control points
between Ortho
–~ Depending on accuracy of Ortho,
maybe +/- 20 meters in horizontal
accuracy
44. 44
Objective
• Identify the proper reference frame
for different differential sources
• Learn how to apply the correct
datum transformation inside PFO
45. 45
Prior to this Presentation
• You occupied “Truth”
• Collected at least one
Point feature
• Now we can compare!
46. 46
Mapping Grade GPS Accuracy
• Verification of accuracy is essential
to gain confidence
• We have to ensure we transform
the data correctly to GIS
49. NAD83 Developed Using WGS84
The origins of the
WGS84 and
NAD83 ellipsoids
are at the center of
the earth’s mass,
which makes them
ideal for a GPS
datum
51. 51
Datum Adjustments
• Known as Datum Adjustments or
Epochs
• WGS84 (G1150) – most current
version
• Most Current NAD83
–NAD83 (CORS96) (Epoch 2003.00)
54. 54
NAD 83 (CORS96) to WGS-84 (G1150)
WGS-84 (G1150)
= ITRF 00 (2001.0)
“TRUTH”
NAD 83 (2003.0)
Anchorage
This is essentially the
CORS or WAAS
Reference Frame
55. 55
Reference
• Locate this support doc and follow along
– 2nd to last reference in Notebook
• SprtNote_PFO-GPSA_NAD83Datum.pdf
57. 57
Since our Reference Frame is
CORS
• Our GPS data is corrected against
a source that is in WGS84 or
ITRF00
• And our GIS is in NAD83
• We therefore define an ITRF00 to
NAD83 Transform
58. 58
Export Out as NAD83 (CONUS)
CORS96
• The reason behind our class
standard
59. 59
To Keep Shifts at Bay
• Verify reference frame of differential
source
60. 60
To Keep Shifts at Bay
• Apply the correct datum
transform before the
Export depending on
your GIS needs
61. 61
Summary
• Identified the proper reference frame
for different differential sources
• Learned how to apply the correct
datum transformation inside PFO
• Keep Shifts at Bay by verifying and
using the right transform
62. 62
If You Use WAAS?
• Since WAAS is ITRF use NAD
1983 (Conus) CORS96
63. 63
If You Use Coast Guard Beacon?
• Since NDGPS is already in NAD83
(CORS96) use NAD 1983 (Conus)
• No need to apply a
transform.