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O U T L O O K The Rajasthan Survey-Resurvey Operations - Method & Scope After processing the satellite imagery, the 'ground truthing' of all parcel boundary corner points and edges are done using DGPS and Electronic Total Station (ETS). The 'ground truthing' term essentially means that the coordinates of each parcel corner and edge that are not visible/unclear in the satellite imagery or those whose identity cannot be deduced from the satellite imagery are measured by DGPS techniques. Where the DGPS technique cannot be used to measure the coordinates of parcel corners and/or edges, such as parcel corner points under tree cover, then the ETS technique is used to measure the coordinates of parcel corners and/or edges. Further, para 5.2.2.8 on '2D features capturing with respect to ortho rectified images' states that 'features those are not visible or unclear shall be captured using ground methods (DGPS and/or ETS) and later integrated with the digitized data'. Para 5.2.2.14 and 5.2.2.18 of the bidding document on 'Grounds Survey Methods to be adopted' and 'Collection and recording of additional map data from the field', respectively, strive to emphasize the above. The acceptable accuracy has been given in para 5.2.2.2 of the bidding document. The para states the general accuracy requirements. The accuracies of coordinates obtained from the screen readout of satellite imageries are acceptable to within 40cm of the coordinates obtained from DGPS/ETS techniques. Whereas the accuracies of the coordinates of points/features that cannot be identified on the satellite imagery, obtained using DGPS/ETS techniques, are accurate to about 2 – 5 cm. For the same parcel the two levels of accuracies are inconsistent and will contribute to the propagation of errors in the whole database. 2 0 G I S R E S O U R C E S | M A R C H 2 0 2 1 The objectives of the NLRMP Project as stated in the document 'The National Land Records Modernization Programme (NLRMP) Guidelines, Technical Manuals and MIS, 2008-09', prepared by the Department of Land Resources, Ministry of Rural Development, Government of India, was the creation of a spatial database of land parcels and integrating the database with the Record of Rights (RoRs). Three methods of survey/re-survey were suggested in the above document, from which, the Govt of Rajasthan has chosen the third method for creating the spatial database. The method of survey/re- survey adopted by the Govt of Rajasthan has been stated in the Bidding document 'Establishment of Ground Control, Network, Conducting Survey/Resurvey and Updation of the Survey & Settlement (Records), Operations in Rajasthan'. In para 5.2.2 of the document under 'Schedule II- Preparation of up-to-date GIS compatible Land Parcel Maps for districts of Rajasthan through hybrid method using High Resolution Stereo Image of satellite (HRSI), Differential GPS and, Electronic Total Survey Station (ETS) in GIS environment, including various attributes/metadata' the hybrid model has been selected as the method of survey/re-survey. The survey/re-survey operations are to be conducted in the entire state. Controls points were established and HRSI imageries were acquired for 11 districts in the initial phase. After generation of ortho-images creation of Khasra map is being done. Acquisition of imageries for the remaining 22 districts is in process. The Hybrid Model of Survey/Resurvey The Digital India LRMP (DILRMP) programme launched in the State of Rajasthan in January 2016, uses 40 cm resolution Quickbird Stereo Satellite Imagery obtained from Digital Globe as the base HRSI. Consistency of the Hybrid Model of Survey/Resurvey The different levels of accuracies of coordinates of parcel corner and edges obtained from satellite imageries and from DGPS/ ETS will create inconsistencies in linear and area measurements. The Higher accuracy of DGPS/ ETS coordinate data when used with the much lower accuracy coordinate data obtained from satellite imageries will lead to inconsistencies in side lengths and area of parcels. Type of Area Target Scale Maximum on Ground Error on Linear Distance Agricultural Land Abadi Land in Village Area 1:4,000 1:1,000 +/- 40cm +/- 20cm Scope for Achieving Higher Accuracy Capture the features, which are not visible in the satellite images Achieve the required accuracy levels in the data by enhancing it by ground survey. It is seen that there is a requirement for improving the consistency of the data being generated. Alongwith improving the consistency of the data, there is also a need to enhance and improve the accuracy of data. Para 5.2.2.13 of the bidding document states the need for 'Enhancement to the data by Ground Survey' wherein higher accuracy levels are required to be achieved. The para states – 'Ground survey using ETS and DGPS enabled smart stations (or equivalent or better) shall be conducted for the following objectives:

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