A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County Scott Farnham, PE, PS City Surveyor, City of Las Cruces NM October 2020

Introduction As part of the ongoing modernization of the U.S. National Spatial Reference System (NSRS), the National Geodetic Survey (NGS) will replace our horizontal and vertical datums (NAD83 and NAVD88) with new geometric datums assigned in the North American Terrestrial Reference Frame of 2022 (NATRF2022). The City of Las Cruces / Dona Ana County and the City of Albuquerque / Bernalillo County submitted proposals to NGS to incorporate Low Distortion Projections (LDP) as part of the New Mexico State Plane Coordinate Systems. Approval by NGS was obtained on June 17, 2019 for the proposed systems (see approval notice). Design of the LDP is the responsibility of the submitting agencies and must be submitted to NGS on or prior to March 31, 2021. Mark Marrujo1 with NMDOT is submitting final LDP design forms to NGS for the State of New Mexico. The City of Las Cruces (City) is designing a new Low Distortion Projection for Public Works Department, Engineering and Architecture projects to NGS criteria. To meet NGS LDP minimum size and shape criterion, the LDP area extends to Dona Ana County (County) boundary lines.

This report presents design analysis and conclusions of the proposed City / County local NGS LDP system for stakeholders’ review prior to NGS final design submittal.

NGS NM SPCS2022 Zones and Stakeholder Organizations NGS is designing new State Plane Coordinate Systems (SPCS2022) for New Mexico. The default SPCS2022 designs for the State are a statewide single zone and the three State Plane Zones: West, Central, and East. The two local LDP zones proposed are part of Layer 3 of the SPCS2022 zones. The submitted NGS SPCS2022 Zone Request and Proposal Form for New Mexico proposed Layer 3 LDP zones lists the following stakeholder organization representatives. NGS requires all stakeholders are supportive of the LDP designs for the March 31st submittal. 1. New Mexico Department of Transportation 2. New Mexico Professional Surveyors 3. New Mexico Board of Licensure for Professional Engineers & Professional Surveyors 4. New Mexico Department of Information Technology – GAC 5. City of Las Cruces 6. Dona Ana County 7. City of Albuquerque 8. Bernalillo County Letters of Support to NGS, William (Bill) Stone2, were provided from: ➢ New Mexico Professional Surveyor’s (NMPS) ➢ New Mexico Department of Transportation (NMDOT)

1 Mark Marrujo, PS: Survey & Lands Engineering Manager, NM Department of Transportation 2 Bill Stone: SW Region (NM, UT, AZ) Geodetic Advisor, NOAA’s NGS

1 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

LDP Objective The objective for a local Low Distortion Projection Coordinate System is to reduce linear distortion at the topographic surface such that it is negligible for most practical applications.

The motivation for a local Low Distortion Projection is to have a consistent set of projected coordinates that yield distances so close to horizontal ground distances that no additional scale factor is required.

Many statewide and LDP systems have been officially adopted by states and local governments: • Wisconsin • Minnesota • Oregon • Kansas • Indiana • Navajo Nation (NM, AZ, UT, CO)

Source: SP_NOS_NGS_13.pdf

1 Examples of U.S. LDP Coordinate Systems

The City / County LDP design objective is based on NGS criteria used in development of the state’s default zones and is tied to linear distortion, population densities, and municipal areas. ❖ A minimum linear distortion that satisfies all three of the following minimum percentages: o 50% of total zone area o 75% of cities and towns, irrespective of population o 90% of zone population

For the City / County, a goal of ±25 ppm or less was selected ➔ 1:40,000 or 0.132 ft per mile (0.025 ft per 1,000 ft).

The City of Las Cruces LDP criterion is a linear distortion of ±15 ppm or less ➔ 1:66,667 or 0.079 ft per mile (0.015 ft per 1,000 ft). A minimum zone size designed by stakeholders needs to meet the following requirements. ❖ Create the largest zone possible, meeting distortion design criterion, to avoid creating an excessive number of small SPCS2022 zones within a state. ❖ Minimum zone width is 50 km (31 miles) for a zone with topographic height range of 250 m (820 ft) or less. For reference, linear distortion changes at a rate of 15.7 ppm per 100 m change in topographic height (4.8 ppm per 100 ft). It decreases (becomes more negative) with increasing height, and vice versa. The reader is referred to Procedures for Design and Modification of the State Plane Coordinate System of 2022 for in-depth criteria review.

2 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

U.S. Survey Foot vs International Foot

New Mexico uses the U.S. survey foot definition, 1 foot = 1200/3937. NGS will deprecate the U.S. survey foot with a planned effective date of December 31, 2022 and is independent of the National Spatial Reference System (NSRS) modernization timeline. We expect New Mexico legislation will eventually change the foot definition to the international foot.

The City / County LDP coordinate system uses the International foot definition: ❖ 1 foot = 0.3048 meter exactly

See the NIST U.S. survey foot site for more details.

Zone Name The City / County LDP design parameters were set on November 5, 2019. Until final NGS approval, and to allow for potential design changes, the City / County LDP reference name is: CLC_5NOV19.

Final submittal zone parameters and test values required on the NGS SPCS2022 Zone Design Submittal Form (Items 9 & 10) will be referenced with the prefix NM_DAC_SPCS2022_Layer3. Final zone names are determined by NGS.

Design Parameters The City / County zone defining parameters must meet NGS criteria, that include: ➢ The zone origin (Latitude/Longitude) and projection axis scale must be unique for all SPCS2022 zones. ➢ Latitude/Longitude be evenly divisible by 3 to avoid infinitely repeating digits. ➢ The projection axis scale defined to 6 decimal places. ➢ Projection grid origins (false northings and eastings) defined in meters with whole numbers evenly divisible by 1,000 meters such that all zone coordinates are positive. ➢ False northing is exactly zero. The City / County LDP design was evaluated using the Transverse Mercator projection (TM) that delivers high accuracy in zones less than a few degrees in east-west extent (current New Mexico State Plane Projection is a TM projection).

The zone origin Longitude was evaluated to best balance population density along the Rio Grande valley and passes close to City of Las Cruces geographic center.

Zone coordinates (meters) range from 12,500N/16,100E at the southwest corner to 474,000N/311,400E at the zone northeast corner.

3 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

Table 1 provides final CLC_5NOV19 LDP parameters.

Table 1 CLC_5NOV19 – A Low Distortion Projection for City of Las Cruces & Dona Ana County

UNITS Metric / iFT (International Feet)

Horizontal Datum NAD83 (2011) epoch 2010.0 (Local Geographic System: EPSG 6318)

GRS80 Ellipsoid: EPSG 7019 Semi-Major Axis 6378137 meter exact Inverse Flattening 298.257222101 unity (12 significant digits min.) .

Vertical Datum NAVD88

Projection Transverse Mercator (Gauss-Kruger form)

GEOID GEOID 18: NGS latest hybrid geoid model, intended to be used with NAD83 (2011) epoch 2010.00. Geoid 18 provides orthometric heights consistent with NAVD 88. See NOAA Technical report NOS NGS 72 for more detail.

Projection Origin Latitude N31°45’00.0” 31.75° Longitude W106°48’00.0” -106.80° (253.20°) False Northing 0.0000 False Easting 52,000.0000 m 170603.675 iFT Scale 1.000195 exact height: 1240 m (4068.2) .

NGS is not expected to release the NATRF2022 datum and geoid until 2024/2025 timeline. NGS uses ITRF2014 / ITRF2020 in their modeling effort and there are interim in-progress xGEOID models available from the NGS web site. See NGS site BETA and Delayed Release of the Modernized NSRS for more information.

NGS Data Release NGS has provided preliminary New Mexico SPCS2022 design and zone linear distortion maps, design Excel spread sheets, and ESRI Shape files for the New Mexico default zones. The shape file and spread sheets provide 1 km ellipsoid height grid points (ITRF2014) and population densities from the 2010 U.S. Census data. The NGS Excel spread sheet, provided by Michael Dennis3, was modified to be specific to the Dona Ana County zone limits. The spreadsheet includes design calculations and statistical reporting from data that includes ITRF2014 1km grid data: ellipsoid heights, grid scale factors, distortion ppm, geometric mean curve radius, latitude and longitude, population grid points, City points and populations. The spreadsheet is complex and may be opened here for review: DAC- CLC_TB_DesignEqArea_ITRF2014.

3 Michael L. Dennis, Ph.D., P.E., R.L.S., M.ASCE: NGS SPCS2022 Project Manager

4 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

Preliminary SPCS2022 Design Maps and Map Data may be downloaded from the NGS site. For New Mexico, the following maps are available and may be viewed with the following links. ➢ Existing SPCS 83 Central Zone Design: 0% population, 0% cities and towns, 0% zone area meet NGS criteria of +/-100 ppm (1:10,000 = +/-0.53 ft per mile).

➢ Preliminary SPCS2022 Default Central Zone: 92% population, 81% cities and towns, 72% zone area meet NGS criteria of +/-100 ppm (1:10,000 = +/-0.53 ft per mile).

➢ Existing UTM Zone 13 North (Used as a statewide zone): 73% population, 48% cities and towns, 50% zone area meet NGS criteria of +/-500 ppm (1:2,000 = +/-2.64 ft per mile).

➢ Preliminary SPCS2022 Statewide Zone: 97% population, 95% cities and towns, 92% zone area meet NGS criteria of +/-500 ppm (1:2,000 = +/-2.64 ft per mile).

Analysis ❖ Proposed Layer 3 Zones Only two new local LDP zones are proposed in New Mexico: City of Las Cruces/Dona Ana County and City of Albuquerque/Bernalillo County. Both zones cover the two largest municipal and highest populated areas in the State and will significantly aid in engineering/surveying projects. Both LDPs are in the New Mexico Central Zone boundary. The two new LDP proposals are not creating an excessive number of small SPCS2022 zones within the state and will provide a consistent set of local projected coordinates without having to apply grid- to-ground scaling. It should be noted that NGS has established processes to handle request for additional LDPs. Proliferation of LDP zones within the state has the potential for adding to confusion and possible misuse. Fig.2: NM SPCS2022 DEFAULT ZONES AND PROPOSED LAYER 3 LDPs

5 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

❖ Zone Size, Cities, and Population Density

Fig: 4: ZONE SIZE: 90 km X 144.8 km (59 X 90 mi) Fig. 3: NGS 1 km POPULATION GRID FROM 2010 CENSUS DATA

County population density is concentrated along the Rio Grande Valley, with City of Las Cruces having the highest populated area. Mountainous ranges within the County have the lowest population counts and include: Caballo Mountains Robledo Mountains Dona Ana Mountains San Andres Mountains East Potrillo Mountains San Augustin Mountains Franklin Mountains Sierra de las Uvas Organ Mountains West Potrillo Mountains The highest County elevation is the Organ Needle and is approximately 2720 m (8920 ft). However, most of the County populated area has an elevation change of 250 m (820 ft) or less. The County Elevation Map is a good thematic view of County elevations and mountain ranges.

A copy of the 2011 County Ownership Map helps understand the varied public/private land use within the County and may be reviewed here: Land Ownership – Dona Ana County.

6 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

Table 2 provides elevation differences within the County. Elevations are from Worldwide Elevation Finder website.

Table 2: Various County Elevations

Elevation Elevation • Lowest County elevation is at the southern County Location Meter FT boundary in the Sunland Park area: 1138 m (3734 SUNLAND PARK 1138 3734 ft) and Organ (unincorporated) is one of the higher communities, an elevation difference of 404 m SOUTH 1179 3868 (1,325 ft). LAS CRUCES • Elevation change between Sunland Park to the NORTH 1192 3911 northwest corner of the County at Garfield, along the LAS CRUCES Rio Grande valley is 114 m (374 ft). HATCH 1234 4049 • Elevation change between Sunland Park and Las CHAPARRAL 1243 4078 Cruces Airport is 215 m (705 ft). GARFIELD 1252 4108 • City of Las Cruces elevation change from south to EAST 1475 4839 north along the valley is 13 m (43 ft). LAS CRUCES WEST County 1306 4285 • City of Las Cruces elevation change from Rio Boundary @I70 Grande to Las Cruces Airport is 174 m (571 ft). LAS CRUCES 1353 4439 • City of Las Cruces elevation change from Rio AIRPORT Grande to City east boundary is 296 m (971 ft). ORGAN 1542 5059 • Maximum elevation change from Sunland Park to Organ Needle 2720 8920 Organ Needle is 1,282 m (4206 ft).

The zone width for the City / County LDP meets NGS requirements and is 90 km (59 miles) which is greater than the minimum width criteria of 50 km.

The NGS design spreadsheet evaluates distortion design criteria for County area, overall County population in 1 km grid, and percent city population. There are 31 cities, towns, villages, and communities within Dona Ana County where 2010 Census data was provided. Five of the communities (Strauss, Lanark, Afton, Aden, Grama) have no population (ghost towns). Incorporated municipalities are Village of Hatch, City of Las Cruces, Town of Mesilla, City of Anthony, and City of Sunland Park.

7 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

Table 3 and Figure 5 provide city, town, community populations and map locations.

Table 3: City, Towns, and Fig: 5: NGS GIS Data – Cities, Towns, and Communities evaluated Community Population (2010)

City 2010 Population Las Cruces 97,618 Chaparral 14,631 Sunland Park 14,106 Anthony 9,360 Santa Teresa 4,258 University Park 4,192 Vado 3,194 Mesilla 2,196 Radium Springs 1,699 White Sands 1,651 Hatch 1,648 Berino 1,441 Dona Ana 1,211 San Miguel 1,153 Mesquite 1,112 La Union 1,106 Salem 942 Chamberino 919 Fairacres 824 San Pablo 806 La Mesa 728 Placitas 576 Rodey 388 Organ 323 Rincon 271 Garfield 137 Strauss --- Lanark --- Afton --- Aden --- Grama ---

8 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

❖ Scale Factor The projection scale factor along the Central Meridian raises and lowers the design grid allowing optimization to meet distortion design criteria. Even though the proposed City / County LDP design meets NGS criteria for cities, population, and area, it is not required by NGS; allowing local design to be optimized for maximum stakeholder benefit based on local knowledge. Table 4 shows how slight variations of the LDP scale factor effects NGS criteria.

Table 4: Central Meridian Scale Factor Effect

% Cities % City Population % Population % Area CRITERIA: >75% >90% >50% +/-30 +/-25 +/-20 +/-30 +/-25 +/-20 +/-30 +/-25 +/-20 +/-30 +/-25 +/-20 SCALE ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm 1.000193 99.0% 96.8% 90.3% 99.8% 99.8% 91.3% 99.0% 97.3% 88.8% 86.3% 77.0% 68.2% 1.000194 99.0% 96.8% 83.9% 99.8% 99.8% 85.1% 99.0% 97.2% 86.8% 85.7% 76.3% 68.1% 1.000195 98.8% 93.5% 77.4% 99.8% 99.7% 73.7% 98.8% 96.8% 81.6% 84.6% 75.9% 67.6% 1.000196 98.8% 90.3% 67.7% 99.8% 91.3% 71.8% 98.8% 93.8% 79.0% 83.4% 75.6% 67.3%

A scale of 1.000195 was selected for final design with a +/-25 ppm distortion criterion.

➢ Cities, Towns, and Communities: Of the 31 County cities, towns, and communities, 29 are within the +/-25 ppm criteria. The two communities exceeding the criteria are: Organ (-43 ppm, 323 pop.) and Garfield (26 ppm, 137 pop.). The median distortion is 16 ppm (0.084 ft per mile).

➢ Population: The scale factor is supportive of 99.7% of County population within cities, towns, and communities; and 96.8% of total County population.

➢ Area: 75.9% of total county area is within the +/-25 ppm criterion. The scale is least favorable to higher elevations of the Organ Mountains, Sierra De Las Uvas Mountains, Robledo Mountains, and Dona Ana Mountains. Grid distortion in these areas can be as low as -204 ppm.

➢ Rio Grande Valley: City of Las Cruces has the highest population density of the County (45% of total County population) and the scale of 1.000195 slightly favors minimizing distortion within the City (+/-15 ppm average).

➢ Northwest of Garfield and a small area of Sunland Park east of the most southerly reach of the Rio Grande, slightly exceeds the +/-25 ppm criterion but is still less than +/-30 ppm. Making slight scale variations, such as 1.000193, only made minor improvements for Garfield and a small sub-area of Sunland Park but had significant impacts to the higher elevations of City areas (Airport – LRU and East Las Cruces) and population along the base of the Organ Mountains.

➢ The selected scale factor is supportive of the entire Rio Grande Valley area.

9 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

❖ Linear Distortion The NGS SPCS2022 NM Central Zone grid data provided in Fig. 6: PARSED NGS SPCS2022 GRID the design spreadsheet was parsed to Dona Ana County. DATA The parsed 1 km grid design points and 2010 census points are shown in Figure 6. There are 10,386 grid points in the model.

Total Grid Population 218,203 City, Town, Village, Community Population 166,490

For each grid point, population point, city point, and point ellipsoid height (ITRF2014); the spreadsheet provides calculations for Earth’s mean geometric radius of curvature, scale factor (k), and point distortion in parts per million (ppm). From the calculations, detailed statistics are generated for the selected LDP. By varying the LDP origin point Lat/Long and central meridian (longitude) scale factor, the user may evaluate different statistical results to optimize final LDP parameters.

The proposed City / County LDP and preliminary NGS SPCS2022 Central Zone (County area) distortion maps are shown below in Figures 7 and 8 for comparison. Click on the map to open the full-size version.

Fig. 8: PROPOSED CITY / COUNTY LAYER 3 Fig. 7: PRELIM. NGS SPCS2022 CENTRAL LDP DISTORTION MAP (SCALE 1.000195) ZONE DISTORTION MAP (SCALE 1.00022)

10 A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

Table 5: Proposed City / County LDP vs SPCS2022 Fig. 9 Proposed CLC_5NOV19 Distortion Contours

City, Town, Population Distortion Community (2010) CLC_5NOV19 SPCS2022 Las Cruces 97,618 12.0 87.3 Chaparral 14,631 20.3 40.4 Sunland Park 14,106 24.6 71.7 Anthony 9,360 21.1 70.1 Santa Teresa 4,258 20.2 74.4

University Park 4,192 11.9 83.4 Vado 3,194 18.1 75.7 Mesilla 2,196 13.2 91.9 Radium Springs 1,699 10.4 108.2 White Sands 1,651 7.2 36.7 Hatch 1,648 18.2 150.0 Berino 1,441 19.1 70.5

Dona Ana 1,211 9.3 89.9 San Miguel 1,153 16.5 85.3 Mesquite 1,112 16.4 79.3 La Union 1,106 19.2 76.8 Salem 942 21.8 162.6 Chamberino 919 17.3 78.6 Fairacres 824 12.7 98.4

San Pablo 806 13.6 88.0 La Mesa 728 16.7 81.3 Table 5 shows distortion differences between the Placitas 576 19.0 153.1 proposed City / County LDP CLC_5NOV19 and the preliminary SPCS2022 Central Zone for cities, Rodey 388 17.2 146.4 towns, and communities within the County. Organ 323 -42.6 4.8 Rincon 271 11.8 130.2 Figure 9 provides a contour line visual for County Garfield 137 25.8 174.2 area within +/-20 ppm, +/-25 ppm, County area exceeding the +/-25 ppm, and the NGS 1 km Strauss --- 3.4 66.8 County population grid points. Click on the map to Lanark --- -0.4 81.1 open the full-size version. Afton --- -0.3 100.7 Aden --- 0.5 129.5 Grama --- -3.0 110.2 Average 12 93.5

Median 16 85 Std. Dev. ±13 ±37

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A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

Summary and Conclusions An acceptable engineering/survey tolerance for small project areas is +/-30 ppm or less and is easily obtained with modern survey equipment. ➢ +/-30 ppm = 1:33,333 ➔ 0.158 ft/mi or 0.030 ft/1,000’ Grid distortion in the existing New Mexico State Plane Coordinate System is less than -250 ppm for most of the County. To obtain ground measurements the user must apply a grid-to-ground scale factor at a project location and ground point coordinates are modified so not to confuse them with actual state plane coordinates. The whole process can become a source for systematic and random errors, particularly when trying to connect multiple project areas, all using different scale factors and coordinates. The new SPCS2022 system greatly improves the New Mexico system and has a median distortion of 85 ppm ±37 ppm for County cities, towns, and communities. Users still must apply a grid-to-ground scale factor and coordinate shift to work at ground level. The NM SPCS2022 has the least distortion for higher elevations and lowest population areas, such as the Organ Mountains and Organ community area. The new zone does not meet stated goals for a City / County coordinate system.

The proposed City / County LDP provides a near ground projection and coordinate system that does not require a grid-to-ground scale factor or coordinate shift for most engineering/surveying/GIS projects within Dona Ana County. The distance distortion limit adopted is +/-25 ppm. The following provides some City / County LDP design statistics: ➢ 99% County population are within +/-30 ppm = 1:33,333 ➔ 0.158 ft/mi or 0.030 ft/1,000’ ➢ 97% County population are within +/-25 ppm = 1:40,000 ➔ 0.132 ft/mi or 0.025 ft/1,000’ ➢ 82% County population are within +/-20 ppm = 1:50,000 ➔ 0.106 ft/mi or 0.020 ft/1,000’ ➢ 66% County population are within +/-15 ppm = 1:66,667 ➔ 0.079 ft/mi or 0.015 ft/1,000’ ➢ 33% County population are within +/-10 ppm = 1:100,000 ➔ 0.053 ft/mi or 0.01 ft/1,000’ The proposed City / County LDP provides project geometric continuity, stability, and standardization. Working with or combining multiple projects in the LDP zone and in the same vicinity is less confusing and potential engineering/survey blunders are reduced for 85% of the County area (+/-30 ppm). The LDP meets City of Las Cruces area engineering/survey criteria and has a distance distortion limit of +/-15 ppm or less for most of the City. No plane projection of a curved surface can eliminate all grid-ground distortion and will not be adequate for all purposes. It will be up to the end user to decide if the LDP provides the necessary distance precisions for their project. Projects such as NMDOT roadway corridors that cross multiple county/state lines have their own plan methods and would not be a typical user of the City / County LDP.

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A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

Earl Burkholder4 provides a good reference article for systematic error in a low distortion projection and LDP trade-offs (see Systematic Error, Low-Distortion Projections©).

There are significant advantages having our local Layer 3 SPCS2022 approved by NGS: ➢ NGS will document all approved designs and associated parameters. ➢ NGS will load defining parameters into an NGS database. ➢ NGS will publish an official report completely defining SPCS2022 and revise as needed to address any changes. ➢ NGS will create and maintain a set of SPCS2022 web pages with links to documents and defining parameters. ➢ NGS maintains a set of geodetic applications and tools that use SPCS2022. ➢ Vendors/manufactures pre-load the NGS coordinate systems defining parameters into their software (e.g. Trimble, ESRI, Autodesk). Within the County, the proposed City / County LDP is supportive of: ➢ High precision land surveying and aerial mapping ➢ High resolution/definition GIS as a business model ➢ Civil Engineering and Architecture ➢ Municipal/County codes for subdivision platting standards ➢ City and County National Flood Insurance Programs ➢ Construction industry (e.g. machine automation) ➢ Agriculture ➢ Airport development and FAA AGIS ➢ Mapping ➢ Real Estate ➢ Land Development and Planning ➢ Future Technology

❖ A Grid vs Ground Distance Example In a recent GNSS survey in the City / County LDP, observations were made on Station Reilly and NGS monument H245. Inverse data from Trimble Business Center provides: ➢ Grid Distance = 4625.127 ±0.007 iFT ➢ Ground Distance = 4625.037 iFT 0.060 Difference Distance Accuracy = 0.060/4625 x 1,000,000 = 13.0 ppm (1:77,000) Grid Point distortion at Station Reilly and H245 are 12.1 ppm and 13.1 ppm.

4 Earl Burkholder, PS, PE: NMSU Emeritus Faculty – retired; President, Global COGO, Inc.

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A Proposed Low Distortion Projection for the City of Las Cruces and Dona Ana County

Final submittal of the City / County LDP to NGS will be made on or before March 31, 2021. Review feedback must be received no later than January 11, 2021. Letters of support are also being solicited from stakeholders.

Stakeholders may provide review feedback to:

Scott Farnham, PE PS City Surveyor/Public Works/Engineering & Architecture Direct: 575-528-3118 Main: 575-528-3333, [email protected]

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