His Coordinates, Interviews


“India is locked in wrong and outdated datum”

Aug 2006 | Comments Off on “India is locked in wrong and outdated datum”

Instead of copying WGS 84, India should explore the opportunity of being a leader in realizing better geodetic system, Dr Muneendra Kumar emphasizes in a tête-à-tête with Coordinates

What are your views about New Indian Map Policy?

To have two map series is a bold and ambitious approach to satisfy both the defense and civilian users. But, based on my experience of working with countries round the world, I have four observations:

1. Selection and use of datum and mapping system are linked with future development and thus should not be “frozen” into any policy. Here, I will point out an example where a particular datum was “protected” under a national constitution. This provision created many roadblocks for the timely development of Geospatial information of that country. In the present case, Government of India has been advised to “lock-in” the wrong and outdated datums, projections, and grid systems. This would create additional hindrances to jeopardize improvement(s) in India’s future modernization.

2. Multiple datums, projections, and grid systems in the two series will create operational problems.

3. Selection and depiction of Geospatial information in any DSMs should be decided one map at a time. I have a very educative experience, which I got in 1967 during my service with Directorate of Military Survey. A feature, otherwise completely “innocent” had to be deleted in one map.

4. It would be practically not possible for India to maintain two map series for its large area. Extent coverage of DSMs should be only over special areas; this would be cost saving also. Finally, considering the geodetic aspect, the most serious problem is that the “Everest/WGS 84” is NOT a valid datum.

In your opinion Indian Datum is inadequate. Please elaborate.

During my service with NGA, I studied and worked with over 250 datums of the world and there I came to know all about the Indian Datum. Not only it is more than a century old, for today’s accuracy requirements, it is extremely “weak” in definition. It has also got distorted. I can elaborate other geodetic inadequacies and accuracy deficiencies, but this interview would not be the right place.

Here, I would add a straightforward factual observation: The 19th century Indian Datum cannot provide “Good Coordinates”, which are critical to satisfy the 21st century high accuracy requirements.

What about the security issues regarding this?

The Survey of India (SOI) has over emphasized the security issue for use of the 19th century Indian Datum. All the pertinent details about it are well known like an open book.

I have certain details, which are very important for protecting India’s national interest. SOI does not know about them. My offer to share and explain the intricacies is still on.

If Indian datum is to be replaced, then why not WGS 84 or a new one like NAD 83?

WGS 84 is a global system developed by U.S. Defense Department for its own requirements. In the absence of any other “global” geodetic system, IHO in 1983 and ICAO in 1989 recommended the use of WGS 84 for sea and air navigation. Other small countries also adopted it as a matter of convenience. Many large countries and/or two continents have realized their own geodetic systems. And, one continent with 50+ countries is still trying to accomplish the same.

However, in recent years, WGS 84 has been realized with incorrect definition. Additionally, there have been new geodetic researches since the 1980ss. Thus, India should not copy the WGS 84, but now has the opportunity to be the leader in realizing a better geodetic system.

As for copying the NAD 83, I had explained to Indian geodesists and also at INCA 2003 that this datum was established as a special effort to replace the NAD 27. It was the most practical solution at that time. I would point out that there was no GPS; otherwise NGS geodesists might have adopted a different approach. I was very much involved in the development of both the NAD 83 and WGS 84 and thus know all about their strengths and limitations.

When India can define and realize a 21st century geodetic system, more so when it is launching new map series, there cannot be any geodetic reasons to copy the 1984 geodetic system or 1983 datum.

What will be the advantages by realizing a new Indian Geodetic Reference System?

The new Indian Geodetic Reference System, if defined correctly with the latest fundamental constants and temporal modeling, and the IAG Resolution No. 16 of 1983, will be the best possible realization, which others would like to copy. It will also become the most accurate foundation for the two map series, nautical and aeronautical charts, height and ocean depth systems, national cadastre and urban mapping, and other Geospatial information.

What are the “logistics” involved?

Based on the experience acquired from the South American project, I would say that a network of about 20-25 fundamental GPS stations would be needed. If the need of principal control stations for airport conversion under ICAO mandate is still there, during actual design process this GPS network can be appropriately expanded by another 10-15 stations. Including safety factor, data collection time at each station will be a maximum of 7 days. Another important point is that the logistic, size, and time for the project for new geodetic system is not to be “tied” to the requirements for dense geodetic control for India’s other projects.

This project is realizable and affordable, if properly designed and executed under good management. The South American SIRGAS 1995 and 2000 projects are good examples. These projects also show the importance of consultation and international cooperation. A few neighbors are waiting for this Indian project.

Whether India needs a new vertical datum of the type like NAVD 88.

Here, I will first point a few specific features and geodetic issues pertaining to NAVD 88. This datum was established as a practical solution to replace the NGVD 29, which had become non-usable due to poor “zero”

definition and excessive distortions. Though Canada participated in the project, it later on did not implement it due to a possible slope of about three meter from East to West. The Helmert’s height system is also geodetically not the best. There are many other zero definition issues, which have full scope for improvement. Thus, NAVD 88, which was established 18 years back, is not the right type to be copied by India.

Since the 1980s there has been new research, which shows that GPS surveyed ellipsoidal heights can replace the orthometric heights and thus India does not need a completely readjusted another BIG vertical datum with orthometric heights.

However, India should maintain the present datum by redefining with geoid as the zero reference.

Does India need a big spiritleveling project towards updating the existing datum?

To maintain the existing datum, new leveling on a big scale is NOT needed. But, re-leveling of week sections and of lines, mostly in areas of crustal movement, should be carried out to replace the existing lines. This releveling effort, if carefully planed and executed, would save lot of time, money, and resources. The updated network is to be adjusted using weighted constraint technique with geoid as zero reference.

For using ellipsoidal heights, what type of a vertical datum is needed?

The 3-D geodetic system is the “datum”, which defines the three position coordinates, viz., latitude, longitude, and ellipsoidal height, of any surveyed point. Here, the reference ellipsoid, as defined within the 3-D geodetic system, is then considered as the “zero” reference for the heights.

This 3-D composite approach thus enables us to replace the centuries old practice defining two separate datums, horizontal and vertical, using two separate ellipsoids.

If ellipsoidal heights can do the job, why they have not been used earlier?

Firstly, the ellipsoidal heights were not used earlier, because they were not available. Secondly, when we started getting them with necessary and sufficient accuracy from GPS surveying, nobody showed any new enterprise to research whether they can be used or not.

My two research papers in COORDINATES show that ellipsoidal heights not only do the jobs, but they do them better, especially in mountainous and remote areas. The “zero” definition is globally consistent and there will be NO conflicts.

For India, the using ellipsoidal heights will have many advantages. Indian users have just to check and test them. After this there should not be any “bar” for not using the new GPS surveyed product.

Here, I would like to point two important issues pertaining to the use of orthometric heights in India. It needs (1) gravity “g” observed at close intervals, and (2) average “g” computed along the plumb line from the ground to the geoid. First requirement is extremely costly and practically very difficult for areas along the Himalayas. The second can never be met. As India did not participate in the NIMA- NASA project of 1996, it still does not have a geoid over its territory with good absolute accuracy. As it now seems that India might not release its gravity data for a global solution, I am sure that Indian geodesists are aware of that theoretical modeling is a very poor option to improve geoid. Furthermore, India only has normal orthometric heights. This means that it requires the quasi-geoid and not the geoid.

Thus, considering the above limitations and fact that India only has normal

heights system, the change over to ellipsoidal heights should be a very practical and money saving option.

Is there any security risk?

There is no security risk in using ellipsoidal heights and/or depths. I do not think that there is anyone who can prove it other way.

Why there should be a new “format” for Indian maps and charts?

First, I would bring out the serious limitations of the currently used projection mapping. In this centuries old traditional approach, the distortions are inevitable. In Universal Transverse Mercator (UTM) projection, which has been accepted for the first time under India’s new map policy, a 10 km EW distance could distort enormously as map coverage moves towards the N- or S-Pole from the Equator. At 80- degree latitude, the distortion is about 600%. The associated grid system has “breaks” at zone boundaries and each zone has its own grid North. In addition, the most serious disadvantage for military operations, discontinuity in grid coordinates is inevitable and occurs frequently at zone junctions within the area covered by any ellipsoid and also at the junctions between two adjoining ellipsoids. Incidentally, in many problems in this global grid system, one major breakdown occurs pertaining to the area covered under the Everest ellipsoid. And, India would have to bear it, just for copying the UTM.

From all this, we had no “escape” before my research of the KMAP System. In this “no-projection” system, maps and charts are seamless with practically zero distortion. They also will have true orientation, no discontinuity in coordinates, and contours drawn with ellipsoidal heights. This new approach is the biggest breakthrough in all making large-scale topographic maps and nautical and aeronautical charts.

In view of the above “real” advantages, I would propose to SOI and all other Indian cartographers to check and test the KMap System for the two new DSMs and OSMs.They will find it a cartographic miracle. Then, adopting the KMap System, India would lead the world in producing the best possible quality DSMs and OSMs.

If the “problems” were there, why they have been and are still in use?

There was NO other alternative mapping system(s). Everyone accepted the projection mapping as the inevitable solution. In case of the U.S. Military Grid Reference System (MGRS), which is now) used with UTM, the

problems have kept mounting since its invention in 1949. But, no consensus and improved solution could be found. With no other option available, users still have to use the same system. Starting its new map series, India has the opportunity to avoid the MGRS, the problematic grid system, which comes with use of WGS 84 and UTM.

Why KMap System?

The KMap System, a 21st century cartographic miracle, provides at least thousands of times better solution compared to any projection(s). It will produce the best quality DSMs and OSMs, including all charts.

What about using Absolute Gravimeter in India. Any comments.

The absolute gravimeter is like a “white elephant”. After buying and surveying a few absolute gravity stations, a country hardly has any substantial use for this extremely costly meter.

However, there are a few friendly countries, which might help India. This would be the most practical approach to get the absolute gravity value established in India.

If India has already committed its funds, there is another alternative to consider building a newly researched “small” absolute gravity meter. This meter can replace the relative gravity surveys and has some potential for selling.

Does India need a big gravity survey campaign?

Under NASA’s gravity mission program, two special satellites have already been successful in collecting gravity data globally. Third satellite is planned for launching in the near future and that will provide, if successful,

very dense coverage. All this data will be available to everyone.

In view of the above, Indian gravity survey plans should be drawn accordingly.

Why India should not be “copying”?

Of course, no one should be “reinventing the wheel”. But, copying a solution for geodetic system or datum from USA, UK, Europe, or any other country might not the best. Instead, with “Good” consultation, countries should come up with better solutions to specifically meet or suit their own needs.

What are the implications of your proposal on Indian security?

I am an independent scientist with my own innovative research ideas and concepts and have experience and expertise to generate “Good” geodetic solutions. I have no ties and hidden motives and am working as a consultant with clean slate with no intention of getting involved with any type of security issues. My proposed solutions are geodetic and scientific with everything crystal clear.

2Dr Muneendra Kumar earned MS, in Mathematics with three gold medals and PhD, in Geodetic Sciences. He is Fellow of the International Association of Geodesy and Marine Technology Society. He served in Survey of India, Indian Military Survey, US National Geodetic Survey, and National Geospatial- Intelligence Agency, from where he retired as Chief Geodesist. Dr Kumar has occupied the Research Professor Chair at the

U.S. Naval University, has been Special Consultant to 100+ countries, and Geodesy Advisor to UN Food and Agriculture Organization. He is an authority on marine positioning and geodesy, and GPS surveying. He is known as Dr. or Senor “WGS84”.

Dr Kumar has numerous presentations, publications, special geodetic and GPS seminars, and workshops to his credit. His pioneering and innovative concepts and researches include Projection and Distortion Free and Seamless Kumar Mapping (KMap) System, GPS Surveyed Time-Invariant Seafloor Depths, and use of ellipsoidal heights in place of orthometric.

The list of projects where he has been consulted is too long. We can put them in five broad categories (1) 55+ countries “ADOS” project for IAG, “AFRICOVER” for UN Food Agriculture Organization, and “AFREF” for IAG Commission for Africa; (2) 25+ countries “SIRGAS” for IAG and PAIGH;

(3) 12+ countries “WHS” for the East European countries; (4) 100+ projects for countries, individually and/or in groups, around the world to update and modernize their geodetic infra-structure, mapping, and height systems; (5) IHO’s adoption of WGS 84 for nautical charts and ICAO’s conversion of Airports.

He is probably the only person who has all the pertinent detailed information about the Indian datum and its various updates used by neighboring countries and also a very critical issues for DSMs. He is also the only expert who participated in the development, defining, and realization of the WGS 84, NAD 83, SIRGAS, NAVD 88, KGS 95, PRS 92, and geodetic systems, vertical datums, and mapping projects of many countries. He is a Guru of marine positioning and boundaries and knows all about the geodetic aspects for the Law of the Sea. He has also researched the best mapping system, survey technique for ocean bottom, and use of ellipsoidal heights. He has the unique combination of highest level of theoretical knowledge and expertise in geodetic systems and mapping with worldwide practical experience.

1 Star2 Stars3 Stars4 Stars5 Stars (3 votes, average: 3.67 out of 5)
Loading...