Ground truth is a term used in a range of remote sensing techniques. It generally refers to the data collected ‘on site’, on the surface of the Earth regarding characteristics of the Earth’s surface features. Ground truth data are complementary to remote sensing data as it helps to link the image data to the ground reality. You should be aware that though the term ‘ground truth’ contains the word ‘truth’, the ground truth data is not always true as it may have errors in it due to factors such as:

The process of collection of ground truth data is known as ground-truthing. Some people also use the terms ‘field work’ or ‘field survey’ or ‘ground survey’ or ‘surface data collection’ or ‘reference data collection’. Ground truth data includes a minimum of three elements i.e. attribute, location and time. Attribute information is the observations that describe ground conditions at a given ground-truthing site. Locational information is helpful in linking the ground observations to match with corresponding points in images and observations related to time and date.

GROUND TRUTHING CARRIED OUT IN 13 STAGES

1. ORTHO IMAGE CAPTURED BY DRONE:

The SOI will fly a Drone over the village and the village habitation. The SOI provides Ortho Rectified image (ORI) to the Village Survey team showing the outline of the Village and habitation boundary

2. ORTHORECTIFIED IMAGE GENERATED BY SOI:

• Drone image captured is processed at the data centre of SOI for rectification of all tilting, sloping etc errors.
• Orthorectified image is given in .ecw format (Enhanced Compression Wavelet) which is aerial photography and satellite imagery captured by Drone.

3. HANDING OVER OF ORI FOR QUALITY CHECK W.R.T GROUND REALITY:

• Hard copies of the images are supplied to the AP Survey team in a scale of 1:1000.
• The SOI, the village survey team and the Mandal survey team shall jointly conduct a quality check of the ORI for its positional and linear accuracy so as to confirm whether it meets the required standards and its feasibility for ground-truthing.
• Distance between two known points in the image is to be compared to the distance between the same two points on the ground.
• The variation should not exceed the defined allowance.
• No of such samples are to be verified and the team has to certify the quality of the image
• If the ORI doesn’t meet the required standards it will be sent back to SOI for further processing
• All the updations as per ground reality to be carried out on this copy.

4. SUPERIMPOSITION OF GEOREFERENCED VILLAGE MAP ON ORTHO IMAGE:

• For the images which are found feasible for ground-truthing after QC, the SOI shall provide superimposed Geo-Referenced Village maps (soft copy in .kml format) on these ORIs.
• Thus, the ORI of the village will be available with the superimposed village map showing the Sy.Nos of the land parcels.
• The SOI provides ORIs (soft and colour hard copy) separately for the entire Village and habitations. The ORI for Village habitation and scattered habitations shall be in a larger scale.

5. GROUND TRUTHING AND ALSO COLLECTION OF ADDITIONAL DATA ABOUT TEMPORARY BUNDS:

• The updated POLR database shall be provided to the Village Survey team along with the backup data for the POLR process in stages I to V and pending issues if any.
• If required, a formal notice in the proforma prescribed may also be issued, as per entries in POLR and served upon every individual landholder, duly informing the date of Survey, Ground Truthing and inviting them to be present at their fields, by obtaining proper acknowledgement.
• The survey team attends to the Ground Truthing by involving all pattadars / Govt. depts. / all stakeholders as per schedule, determines and records undisputed boundaries of individual land Parcels, duly marking them on ORI hard copy.
• The team shall have all necessary survey equipment namely, GNSS Rovers, ETS systems, Chain & Cross staff etc.
• Where ever the Field boundary points are not distinctly visible in the ORI, GNSS Rovers/ETS instruments shall be used to do field measurement exactly( Ex: Orchard, Coconut gardens, bushes etc.). Geocods data of all field boundary points will definitely be collected as additional information.
• All permanent field boundaries as shown by the landholders shall be demarcated on ORI to reflect the true ground position. All Permanent field boundaries must be properly demarcated.
• Wherever any boundary is disputed, the village team after making a detailed enquiry will make a speaking order, deciding and determining the boundary, Under section 10(1) of AP S & B Act. Such decided boundary shall be recorded and marked on ORI hard copy.
• The survey team shall record remarks if any in the POLR datasheet as provided.
• The survey team will also record all the details in a Field Register prescribed by the CSS & LR. This will mainly consist of: 

1. 1. Verification of the boundaries of the land parcels and issues if any.
   2. The details of GeoCods of the missing boundary points, not legible boundary points etc.
   3. Attributes of the land parcels.
   4. Confirmation of the mobile number of the concerned Pattadar/Occupier

6. QUALITY CHECK OF GROUND-TRUTHING &ADDITIONAL INFORMATION:

• The Mandal team consisting of Dy. Tahsildar and Mandal Surveyor shall check the quality of the Ground Truthing carried out as per the prescribed process by CSS &LR
• All the additional information obtained during the Ground Truthing exercise, both in the remarks of the POLR and Field register shall be 100% scrutinized by the Mandal Team.
• Such quality checked information shall be also checked randomly by the Tahsildar, Dy.Inspector of Survey and the RDO/Sub-Collector.
• On due certification, the records shall be handed over to the District processing team.

7. DATA PROCESSING AND INTEGRATION WITH POLR:

• The Survey of India  will Vectorize the ORI using all the additional data. Provide, updated ORIs. Generate the Village map with LP Numbers.
• A statement showing each land parcel number and its area will also be generated.
• Superimpose the Village map with Land Parcel numbers on the Geo-referenced Village map with Sy. Nos and Subdivision Nos. Prepare the Correlation Statement for each Land parcel, both Sy.No/ Subdivision No wise and LP Number wise.
• The SoI will Vectorize the ORI using all the additional data. Provide, updated ORIs. Generate the Village map with LP Numbers.
• A statement showing each land parcel number and its area will also be generated.
• Superimpose the Village map with Land Parcel numbers on the Geo-referenced Village map with Sy. Nos and Subdivision Nos. Prepare the Correlation Statement for each Land parcel, both Sy.No/ Subdivision No wise and LP Number wise.
• All updated Data will be given to the village teams in two statements:
  • The first statement will be the updated POLR duly showing all the Correlated land parcel numbers, extent etc. for each of the Sy.No. Sub-Division No.
  • The second statement will be a similar statement containing all the information of the updated POLR but will be LP No. Wise. This statement is the most important statement which is being developed in the Webland Gold document.
• This preliminary web land Gold document will be used by the village team to do the Ground validation for each land parcel and record the correct entries by editing the entries.

8. GROUND VALIDATION:

• A formal information to Landholders to attend ground validation shall be given by the village survey team to all the Landholders, govt land depts by the conduct of Gramasabha and also display of this information at conspicuous places and website of CSSLR and local publicity by the beat of Tom-Tom.
• The Village Survey team shall again visit each Land parcel with the concerned Landholders/depts. / stakeholders and confirm the Land parcel boundaries. For the landowners who agree with the details, an appropriate format to be used for taking acceptance.
• For landowners who do not accept, the area of the land parcel, measurements may be done by GNSS Rover. If still not agreed, it may be done using the ETS machine. If necessary physical measurements and area calculations may be done in the D&O system using chain & cross-staff. 
• For any other data where there is a non-satisfaction appropriate action may be taken under the provisions of Act, Rules, G.O.s. All efforts should be made to resolve the non-agreement except those which are in court/revenue cases.
• Additional information to be collected by the validation team for the following:
  • Variation in Geo-codes for which correction is required.
  • Variation in Correlation of the sketch wherever corrections are required.
  • Any further corrections in POLR.

9. QUALITY CHECK OF GROUND VALIDATION & ADDITIONAL INFORMATION:

There shall be a Mandal level quality check team and divisional level quality check team for quality check of the work done by the village survey team.

10. DATA PROCESSING AND UPDATION OF RECORDS:

• Update all necessary records as per the additional information received in validation. 
• Generate draft survey records which include village map, all LPMs, updated Land records, Govt land registers, assigned and allotted land registers etc., and is given to the village team.
• After the quality check, the draft records shall be prepared and submitted to the Tahsildar for scrutiny of Records.
• The Tahsildar and Mandal surveyor verifies whether all Govt. lands are properly resurveyed and recorded in the records and in the field. The RDO/ Sub Collectors also do the cross-check. This is a special step to ensure that all Govt lands are protected.

11. STATUTORY NOTICES:

Village Survey team issues notice u/s 9(2) and 10(2) duly communicating the decisions to the registered landholders and to the parties to the dispute and landholders respectively.

• Any person affected by a decision U/S section 9 or 10 may file an appeal U/s 11 to the appellate authority (mobile Mandal Magistrate team) within 30 days from the date of receipt of such notice. The system is being worked out to receive these appeal petitions in the Village Secretariat itself.
• The mobile magistrate team shall have the necessary systems to receive the appeals, verify each of the appeals, hear the pattadar / person, conduct an enquiry, field inspection and issue speaking orders. A Computer Software will be in operation for the Registration of the appeals, fixing of the hearing dates and field inspections and uploading of orders.
• All the appeal petitions shall be disposed of within 30 days of the last date of filing of appeals. Thus, the total period for receiving objections and disposal is of 60 days.

12. STONE PLANTATION PHASE:

In the cases where no appeals are received stone plantation shall be taken up immediately. For the remaining parcels, it shall be taken up after disposal of the appeal and communication of the order to the appellant.

13. FINAL RECORDS:

• Any updation in the survey records shall be carried out only as per the orders of the mobile magistrate.
• The survey records and the land records have to be transferred to the newly created permanent Database of Survey and land records.
• A Unique land parcel id will be integrated into each parcel number which will become like an aadhar for each land parcel.( NIC + SOI)
• The permanent survey and land records(Village map, LPMs, Land Register) shall be prepared for notification by the village team and the Mandal team and shall be notified by the District Competent Authority u/s 13 of the Act. It shall definitely include the unique id number, the land parcel number and the correlated old survey subdivision number.
• After the publication of U/S section 13, any aggrieved person by the Mandal Magistrate orders, can prefer filing a civil suit as per the provisions of section 14 of AP Survey and Boundaries Act.
• Such notified Survey and land record shall become the permanent resurvey record and shall be maintained in a newly created permanent Database.
• The Permanent Database shall be used to generate the necessary registers under the Titling Act. Necessary notifications shall be done in this regard. The new permanent database will have adequate integration of subdivision/ amalgamation of land parcels, Registration / Succession and mutations so that the data is in a purified manner at all times. The Unique id of the Land parcel will also have the appropriate system so that all subdivisions/amalgamations are properly accounted for.

Points to be remembered regarding Ground Truthing(From SOP):